Hello,
Required materials
Phenylacetic acid
Acetic acid
Thorium oxide or manganese oxide
Nitrogen gas
First, build a furnace.
The way to build a furnace is as follows:
Connect a sep funnel to the adapter connecting to the condenser and place a mechanical stirrer inside the sep funnel.
Connect the nitrogen gas inlet tube to this part.
Fill the condenser with small stones cleaned with acetone (completely filled).
If you don't have stones, break a glass and fill it.
Pour manganese oxide or thorium oxide into these stones.
Connect an outlet adapter for nitrogen gas to the end of the condenser, which is connected to the discharge flask.
Middle part Heat the condenser with direct flame heat and slowly, while you are mixing phenylacetic acid and acetic acid (the stirrer in the sep funnel is stirring), open the sep valve and wait 15 minutes for every 3 shots that you direct the liquid into the condenser.
You will see phenylacetone coming out of the outlet, which of course is not pure, but you can distill it with vacuum or steam.
Tip (First pour the phenylacetic acid on the newspaper and place a fan in front of it because it quickly combines with the humidity in the air)
Adjust the amounts one by one.
For example, every 50 grams of phenylacetic acid requires at least 50 grams of acetic acid, but to be more sure, pour 57 grams of acetic acid.
The problem with this method is that thorium oxide is very expensive and difficult to find, but you may be able to find manganese oxide.
Required materials
Phenylacetic acid
Acetic acid
Thorium oxide or manganese oxide
Nitrogen gas
First, build a furnace.
The way to build a furnace is as follows:
Connect a sep funnel to the adapter connecting to the condenser and place a mechanical stirrer inside the sep funnel.
Connect the nitrogen gas inlet tube to this part.
Fill the condenser with small stones cleaned with acetone (completely filled).
If you don't have stones, break a glass and fill it.
Pour manganese oxide or thorium oxide into these stones.
Connect an outlet adapter for nitrogen gas to the end of the condenser, which is connected to the discharge flask.
Middle part Heat the condenser with direct flame heat and slowly, while you are mixing phenylacetic acid and acetic acid (the stirrer in the sep funnel is stirring), open the sep valve and wait 15 minutes for every 3 shots that you direct the liquid into the condenser.
You will see phenylacetone coming out of the outlet, which of course is not pure, but you can distill it with vacuum or steam.
Tip (First pour the phenylacetic acid on the newspaper and place a fan in front of it because it quickly combines with the humidity in the air)
Adjust the amounts one by one.
For example, every 50 grams of phenylacetic acid requires at least 50 grams of acetic acid, but to be more sure, pour 57 grams of acetic acid.
The problem with this method is that thorium oxide is very expensive and difficult to find, but you may be able to find manganese oxide.
Phenylacetone, also known as methyl benzyl
ketone, or l-phenyl-2-propanone, is easy to make
if one can get the chemicals. In this reaction,
phenylacetic acid reacts with acetic anhydride
with pyridine catalysts to produce phenylacetone
plus carbon dioxide and water.
A Russian journal tells of using sodium acetate
instead of pyridine. For nearly two decades now,
I have let one sour experience with this reaction
convince me it is useless, an example of lying
commie science. I have been convinced that my
judgment on this Russian variation was prema-
ture, and it really does work. We'll talk more
about that method at the end of this chapter, but
first let's cover the version using pyridine. I have
done this reaction many times.
The reaction is done as follows: Into a clean,
dry 3000 ml round bottom flask is placed 200
grams of phenylacetic acid, 740 ml of acetic an-
hydride and 740 ml of pyridine. This is done on a
table covered with a sheet of newspaper, because
phenylacetic acid, once it is exposed to the air,
smells like cat urine, and the smell is next to im-
possible to get rid of. Pyridine also smells awful.
The pyridine and acetic anhydride are measured
out in a large glass measuring cup.
The flask is then gently swirled until the
phenylacetic acid is dissolved. The flask is then
assembled with the 50 cm condenser and the vac-
uum adapter, as shown in Figure 9. Before as-
sembly, the joints are lightly greased with sili-
cone-based stop cock grease. This prevents the
pieces from getting stuck together. All pieces
should be clean and dry. The vacuum nipple of
the vacuum adapter is plugged with a piece of
tape. In the rounded section of the vacuum
adapter is a plug of cotton, then about two tea-
spoons of Drierite (anhydrous calcium sulfate),
then another plug of cotton. This makes a bed of
Drierite, which is prevented from falling into the
flask by a ball of cotton. The purpose of this is to
keep moisture from the air away from the reac-
tion.
Now the underground chemist is ready to begin
heating the flask. Notice that in Figure 10, the
flask is in a large pan, which sits on the buffet
range. The pan is filled about half-full of cooking
oil (Wesson works fine). This is so that the flask
is heated evenly. The heat is turned about half
way to maximum, and the flow of cold water
through the condenser is begun. A length of plas-
tic or rubber tubing runs from the cold-water fau-
cet to the lower water inlet of the condenser. The
cold water runs through the condenser and out of
the top water exit, through another length of tub-
ing to the drain. In this way, the rising vapors
from the boiling pyridine are condensed and re-
turned to the flask. A rate of water flow of about
one gallon per minute is good.
Within a half hour, the flask is hot enough to
begin boiling. The heat is then turned down to
stabilize the flask at a gentle rate of boiling. This
is called a reflux. The boiling is allowed to con-
tinue for seven hours. During this time, the reac-
tion mixture turns from clear to brownish-red in
color. Periodically, the rate of water flow coming
out of the condenser is checked, because faucet washers tend to swell after a while and slow
down the rate of water flow.
After seven hours, the heat is turned off.
Twenty minutes after the boiling stops, the
glassware is set up as shown in Figure 11. The
cotton and Drierite are removed from the vacuum
adapter. Then four pea-sized pieces are broken
off a pumice foot stone (purchased at the local
pharmacy). These are called boiling chips, be-
cause they cause liquids to boil faster and more
evenly. They are added to the flask with the reac-
tion mixture in it. But they are not added until 20
minutes after the boiling stops; otherwise they
could produce a geyser of hot chemicals.
Now the heat is turned back on, a little hotter
than when refluxing the reaction mixture. Water
flow to the condenser is resumed. The mixture
soon begins boiling again and the vapors con-
dense in the condenser and flow to the collecting
round bottom flask. What is being boiled off is a
mixture of pyridine and acetic anhydride. The
phenylacetone remains behind in the distilling
round bottom flask, because its boiling point is
about 100 degrees Celsius higher than the pyri-
dine and acetic anhydride. This process is called
simple distillation. Distillation continues until
1300 ml has been collected in the collecting
round bottom flask, then the heat is turned off.
The 1300 ml is poured into a clean dry glass jug
about one gallon in size, which is then stoppered with a cork. Later in this chapter, I will describe a
process by which this pyridine is recycled for fu-
ture use. Since pyridine is so expensive, this cuts
production costs considerably.
What is left in the distilling round bottom flask
is a mixture of phenylacetone, some acetic anhy-
dride and pyridine, and a high-molecular-weight
tarry polymer, which is reddish-brown in color.
The next step is to isolate and purify the
phenylacetone.
The flask is taken out of the hot oil arid allowed
to cool down. Three-quarters of a gallon of 10%
sodium hydroxide solution (NaOH) is needed. So
a gallon-size glass jug is filled three-quarters full
of cold water and about 10 ounces of sodium hy-
droxide pellets are added to it. A good quality lye,
such as Red Devil or Hi-Test, is a substitute that
saves a good deal of money and works fine. Eye
protection is always worn when mixing this up. It
is mixed thoroughly by swirling, or by stirring
with a clean, wooden stick. The dissolution of
NaOH in water produces a great deal of heat. It is
allowed to cool off before the chemist proceeds.
About 500 ml of the 10% NaOH is put in a
1000 ml sep funnel, then the crude phenylacetone
mixture from the round bottom flask is poured in
the sep funnel also. The top of the sep funnel is
stoppered and mixed by swirling. When the fun-
nel gets hot, it is allowed to set for a while. Then
the mixing is continued, with the underground
chemist working his way up to shaking the sep
funnel, with his finger holding in the stopper.
What he is doing is removing and destroying the
acetic anhydride. Acetic anhydride reacts with the
sodium hydroxide solution to produce sodium
acetate, which stays dissolved in the water, never
to be seen again. Some of the pyridine and red-
colored tar also goes into the water. The destruc-
tion of the acetic anhydride is what produces the
heat.
After it has cooled down, about 100 ml of tolu-
ene is added to the sep funnel and shaken vigor-
ously for about 15 seconds. The sep funnel is un-
stoppered and allowed to sit in an upright position
for about one minute. The liquid in the funnel
will now have separated into two layers. On top is a mixture of toluene, phenylacetone, and red tar.
On the bottom is the water layer, which has some
phenylacetone in it. Pyridine is in both layers.
Two 500 ml Erlenmeyer flasks are placed on
the table, one marked "A," the other marked "B."
The stop cock on the sep funnel is opened, and
the water layer is drained into B. The top layer is
poured into A. B is poured back into the sep fun-
nel, and 50 ml of benzene is added. The funnel is
shaken for 15 seconds, then the water layer is
drained back into B. The top layer is poured into
A. The purpose of this is to get the phenylacetone
out of the water. Once again the water in B is put
in the sep funnel. Fifty ml of toluene is added,
and shaken. Xylene is for almost all purposes
substitutable for toluene, and is at present easier
to get at the hardware store. The water is drained
into B and the toluene layer poured into A. The
water in B is poured down the drain and the con-
tents of A put into the sep funnel along with 400
ml of 10% NaOH solution from the jug. After
shaking, the water layer is drained into B and the
toluene layer poured into A. The contents of B
are put back in the sep funnel and 50 ml of tolu-
ene added. After shaking, the chemist drains the
water layer into B and pours it down the drain.
The contents of A are added to the funnel again,
along with 400 ml of 10% NaOH solution; the
funnel is shaken again. The water layer is drained
into B and the toluene layer poured into A. The
contents of B are returned to the sep funnel, along
with 50 ml toluene, and shaken again. The water
layer is poured into B and poured down the drain.
The toluene layer is poured into A. The sep fun-
nel is washed out with hot water.
Now the last traces of pyridine are removed
from the phenylacetone. For this purpose, some
hydrochloric acid is needed. Hardware stores
usually have the 28% strength sometimes called
muriatic acid. A bottle in which the acid seems
clear-colored is used; the ones with a green tint
have been sitting around too long.
The contents of A are returned to the clean sep
funnel. Then 10 ml of hydrochloric acid, mixed
with 10 ml of water, is added to the sep funnel
and shaken for 30 seconds. The stopper is pulled out to check whether or not the odor of pyridine
has disappeared. If not, another 20 ml of the acid-
water mix is added and shaken. The odor should
now be gone, but if it is not, some more of the
mix is added and shaken. Now 200 ml of water is
added and shaken. Flask A is rinsed out with hot
water; the water layer is drained into B and
poured down the drain. The toluene layer is
poured into A. What has just been done is to con-
vert the pyridine into pyridine hydrochloride,
which dissolves in water, but not in toluene. It is
now down the drain.
Finally, for one last time, the contents of A are
returned to the sep funnel, along with 200 ml of
the 10% NaOH solution. This is shaken and the
water layer drained into B. The toluene layer is
allowed to stay in the sep funnel for the time be-
ing; more water will slowly fall out to the area of
the stop cock, where it can be drained out. It is
now ready to be distilled, and stray water must be
removed beforehand.
which an underground chemist can make
himself. The claisen adapter is checked to make
sure it is clean and dry. A clear glass beer bottle
is washed out with hot water, then smashed on
the cement floor. A few pieces are picked out that
are small enough to fit in the lower opening of the
claisen, yet big enough that they will not fall out of the bottom opening of the claisen adapter.
Pieces of the broken bottle are dropped in the
lower opening until that section of the claisen
adapter is filled to about the level shown in the
drawing. The chemist tries to get it to land in a
jumbled pattern, as shown in the drawing. Then
more similarly sized pieces of glass are dropped
in the upper opening of the claisen adapter until it
is filled to the level shown. Again a jumbled pat-
tern is striven for. The lower opening is then
stoppered with the proper size of glass or rubber
stopper. Finally, the outside is wrapped with a
layer or two of aluminum foil, except for the
ground glass joint.
The underground chemist will now distill the
phenylacetone. First, here is some information on
the process to be performed. The crude
phenylacetone the underground chemist has is a
mixture of toluene, phenylacetone, red tarry
polymer, some water and maybe some dibenzyl
ketone. These substances all have very different
boiling temperatures. By distilling this mixture
through a fractionating column, the chemist can
separate them very effectively and get a high-pu-
rity product. The way it works is easy to under-
stand. The vapors from the boiling mixture in the
distilling flask rise up into the fractionating col-
umn and come into contact with the pieces of
glass inside. Here the vapors are separated ac-
cording to boiling point. The substance in the
mixture with the lowest boiling point is able to
pass on through, while the other substances are
condensed and flow back into the distilling flask.
This is why the pieces of glass in the column
can't be tightly packed, as that would interfere
with the return flow, leading to a condition called
flooding. Once all of the lowest-boiling substance
has been distilled, the substance with the next
higher boiling point can come through the frac-
tionating column. In the distillation process to be
described, the order is as follows: toluene-water
azeotrope, 85° C; toluene, 110° C; phenylacetone,
120-130° C (under a vacuum of about 20 torr).
Why must the phenylacetone be distilled under
a vacuum? Because its boiling point at normal pressure is 216° C, which is much too hot. Dis-
tilling it at that temperature would ruin the prod-
uct. By distilling it under a vacuum, it boils at a
much lower temperature. The exact temperature
depends on how strong the vacuum is; the
stronger the vacuum, the lower the temperature.
For example, at a vacuum of 13 torr, the boiling
point goes down to about 105° C.
The glassware is set up as shown in Figure 13.
The distilling flask is no more than
2/3 full. If the
underground chemist has more crude phenylace-
tone than that, he has to wait until some of the
toluene has distilled off, then turns off the heat,
waits until the boiling stops and adds the rest of it
to the distilling flask.
The glassware should be clean and dry. A fast
way to dry glassware after washing is to put it in
the oven at 400° F for 20 minutes. Rubber stop-
pers do not go in the oven. Water tends to stay in-
side round bottom flasks dried in this way. So,
while they are still hot, the chemist takes a piece
of glass tubing and puts it inside the flask. He
sucks the moist air out of the flask with the glass
tubing before it has a chance to cool down and
condense. For the distillation, two 250 ml round
15
bottom flasks are needed, one to collect the tolu-
ene in, the other to collect the phenylacetone in.
Five boiling chips are put in the distilling flask.
The heat source is turned on, to the low range,
about 1/4 maximum. Water must be flowing
through the shorter condenser at about one gallon
per minute. When the mixture has begun boiling,
the heat is adjusted so that about one or two drops
per second drip into the collecting flask. The
temperature on the thermometer should say about
68° C. For accurate temperature readings
The material distilling at 85° C is the toluene-
water azeotrope. It is about 80% toluene and 20%
water. It is milky white from suspended droplets
of water. Once the water is all gone, pure toluene
is distilled at about 80° C. It is clear in color. If
the liquid in the collecting flask is not clear or
white in color, then undistilled material is being
carried over from the distilling flask. This is
caused either by having the distilling flask too
full or by having the heat turned too high. In ei-
ther case, the chemist must correct accordingly
and redistill it. Once the temperature reaches 115°
C on the thermometer, or the rate of toluene ap-
pearing in the collecting flask slows to a crawl, the heat is turned off because the chemist is ready
to vacuum distill the phenylacetone.
There is a problem that is sometimes encoun-
tered while distilling off the toluene. Sometimes
the toluene in the distilling flask will foam up in
the distilling flask instead of boiling nicely. These
bubbles refuse to break and they carry undistilled
material along with them to the collecting flask,
leaving a red liquid over there. This cannot be
allowed to happen. One effective method of
dealing with this is to turn on the water supply to
the aspirator at a slow rate so that a weak vacuum
is produced. Then the vacuum hose is attached to
the vacuum adapter and a weak vacuum produced
inside the glassware. This causes the bubbles to
break. Every few seconds, the vacuum hose is
removed, then reattached. In a while, the toluene
begins to boil normally and the vacuum can be
left off.
After it has cooled off, the collected distilled
toluene is poured into a labeled glass bottle. It can
be used again in later batches of phenylacetone.
The same 250 ml round bottom flask is reattached
to the collecting side, and the vacuum hose at-
tached to the vacuum adapter. The vacuum source
is turned on. If an aspirator is being used, the
water is turned all the way on. All the pieces of
glassware must be fitted snugly together. A
strong vacuum quickly develops inside the glass-
ware. The heat is turned on to about
]/3 maxi-
mum. The boiling begins again. At first, what
distills over are the last remnants of toluene and
water left in the distilling flask. Then the tem-
perature shown on the thermometer begins to
climb. The phenylacetone begins to distill. When
the thermometer reaches 100° C, the vacuum
hose is removed and the collecting 250 ml flask is
replaced with the clean, dry 250 ml flask, then the
vacuum hose is reattached. If a good vacuum
pump is being used, the flasks are changed at
about 80° C. This flask changing is done as fast
as possible to prevent the material in the distilling
flask from getting too hot during the change over.
If it gets too hot, it distills too rapidly when the
vacuum is reapplied, resulting in some red tar
being carried over along with it.
The vacuum is reapplied, and the phenylace-
tone is collected. With a properly working aspi-
rator, the phenylacetone will all be collected once
the temperature on the thermometer reaches 140-
150° C. With a good vacuum pump, it will all
come over by the time the temperature reaches
110-115° C. Once it is all collected, the heat is
turned off, the vacuum hose is removed from the
vacuum adapter and the vacuum source is turned
off.
The yield is about 100 ml of phenylacetone. It
should be clear to pale yellow in color. It has a
unique but not unpleasant smell. The flask hold-
ing this product is stoppered and stored upright in
a safe place. Although phenylacetone can be
stored in a freezer to keep it fresh, the chemist now proceeds to making N-methylformamide.
Once the distilling flask has cooled down, the
glassware is taken apart and cleaned. The red tar
left in the distilling flask and the fractionating
column is rinsed out with rubbing alcohol. Then hot soapy water is used on all pieces. A long, nar-
row brush comes in handy for this.
One last word about vacuum distillation. To
keep the vacuum strong, the vacuum hose is no
more than three feet long. This forces the chemist
to do the distilling close to the source of the vac-
uum.
Now for that pyridine recycling process I men-
tioned earlier in this chapter. After the under-
ground chemist has made a few batches of
phenylacetone, he will have accumulated a fair
amount of pyridine-acetic anhydride mixture in
the gallon-sized glass jug. He will now fraction-
ally distill it to recover the pyridine from it. The
clean dry glassware is set up as shown in Figure
15. It has a long fractionating column instead of
the short type just used. This is because pyridine
and acetic anhydride are harder to separate, so a
longer column is needed to do the job.
The distilling flask is a 3000 ml round bottom
flask with 5 boiling chips in it. The chemist pours
2000 ml of the acetic anhydride-pyridine mixture
into it. The heat is turned on to about '/3 maxi-
mum and the cold water is started flowing slowly
through the condenser. Within a half hour, the
mixture will begin to boil. A couple of minutes
later, the vapors will have worked their way
through the fractionating column and begin ap-
pearing in the 2000 ml collecting flask. The heat
source is adjusted so that it is collecting at the
rate of one or two drops per second. Distilling is
continued until 1000 ml have accumulated in the
collecting flask. If the temperature reading on the
thermometer goes above 135° C, the heat is
turned down a little to slow the rate of distillation.
Once 1000 ml has been collected, the heat is
turned off and it is allowed to cool down. After it
is cool, the distilling flask is removed and its
contents (mainly acetic anhydride) poured down
the drain. The contents of the collecting flask
(mainly pyridine) are poured into a clean, dry
2000 ml round bottom flask with 5 boiling chips,
or 5 boiling chips are simply added to the 2000
ml round bottom flask that the pyridine collected
in and that flask is put on the distilling side in
place of the 3000 ml flask. A clean, dry 1000 ml
17
round bottom flask is put on the collecting side.
The heat is turned back on and in a while the dis-
tilling begins again. As before, the rate of distil-
lation is adjusted to one or two drops per second.
The distillation is continued until 750 ml of pyri-
dine has been collected. Sometimes it does not
keep well, but so long as it is used to make an-
other batch of phenylacetone within a few hours
after it is made, this pyridine works just as well as
new pyridine.
Now let's talk about the Russian recipe, and
how I messed it up when I was a neophyte cooker
20 years ago, and the right way to do it. The Rus-
sian recipe, which dates to about 1940 during the
height of Stalin's wackiness when all sorts of po-
litically motivated "science" was turned out by
people fearing losing their lives if they didn't get
the "politically correct" results, calls for mixing
420 grams of phenylacetic acid with 700 ml of
acetic anhydride and 210 grams of sodium acetate
in a 2000 ml flask. Two advantages are obvious
here. The expensive reagent pyridine has been re-
placed with the cheap chemical sodium acetate.
Also, the reaction is being done considerably
more concentrated than with the pyridine recipe,
i.e., more phenylacetic acid is getting poured into
the 2000 ml flask, so more phenylacetone will be
produced at a single cooking session.
Back in, I think it was 1979, I tried this recipe
using a standard round bottom flask, which I just
set upon a magnetic stirrer hot plate, and began to
cook. Just setting a round bottom flask on a hot
plate surface is a poor way to heat this flask. I had
to turn the heat up to maximum just to get it to
start to boil. Shortly thereafter, the magnetic stir-
rer motor burned out from all the heat from the
hot plate, and the sodium acetate just sat at the
bottom of the flask with the weak boiling I was
making. At the end of the 18 hours of prescribed
cooking, I got maybe a 20% yield of product, and
was soured on this method for 20 years.
Now for the right way to do this reaction. First
of all, an oil bath or heating mantle should be
used to heat the reaction flask, because a weak
and puny boil isn't sufficient. The reaction mix-
ture must reach 145-150° C. Acetic anhydride
boils at 139° C, but with the higher boiling
phenylacetic acid mixed into the solution, and
similarly high boiling point phenylacetone being
produced, it's not too hard to make the solution
reach this temperature if it is being boiled good
and hard. With a good hard boil like that, just one
condenser isn't enough. One must use a three-
necked flask, and attach a condenser on two of
the necks, and plug the third neck with a glass
stopper No stirrer is really necessary with this reaction,
as the strong boil will lift sodium acetate off the
bottom of the flask, and mix it with the solution.
Three-necked flasks are a bitch to get these days,
but stainless steel is fine for this reaction, as is a
Teflon-coated metal replica. As an added bonus,
using metal replicas makes it impossible to bust
one for having glassware for the purpose of
making meth, a 10-year felony under the Meth
Act of 1996. Drying tubes should be attached to
the tops of the condensers, as in the example us-
ing pyridine.
Heat the oil to about 160° C or so to get a good
boiling inside the flask, and let cook for 18 hours.
At the end of the cook, allow the flask to cool,
then pour the reaction mixture into a gallon of
cold water. Phenylacetone will float on top of the
water, and the acetic anhydride and sodium ace-
tate will stay in the water.
Using a sep funnel, separate off the
phenylacetone from the water, and pour it into a
convenient container. Now extract the water layer
with two 200 ml portions of toluene, and add
these extracts to the phenylacetone. The water
can now be thrown away. The combined
phenylacetone and toluene extracts should next
be poured into a large sep funnel, and washed two
times with 500 ml portions of 5% sodium hy-
droxide or lye solution in water. This will destroy
any acetic anhydride left floating around.
The toluene solution containing the
phenylacetone is poured into a beaker, and al-
lowed to sit for a few hours. Some water will fall
out of the solution, and sit on the bottom of the
beaker.
Next, the toluene solution containing the
phenylacetone is poured into a distilling flask,
and a distillation is done, just like in the recipe
using pyridine. First, the toluene-water azeotrope
distills, drying the mixture, then pure toluene dis-
tills. The toluene can be reused. When the toluene
has distilled, the mixture is allowed to cool some
before commencing vacuum distillation of the
phenylacetone. The Russians would have you be-
lieve that about 400 ml of phenylacetone will re-
sult from the cook. I have been told by people in
a position to know that 300-350 ml is more likely.
Not a bad day's work, by any means.
An alternative procedure for making
phenylacetone from phenylacetic acid can be
found in The Journal of the Society of Chemical
Industry, Volume 44, pages 109-112 (1925) and
in the Journal of the Chemical Society, Volume
59, pages 621-629 (1891). In this method, the
calcium salts of phenylacetic acid and acetic acid
are mixed together and then heated. The product
we want, phenylacetone, distills out of the reac-
tion mixture. The advantage to this method is that
acetic anhydride and pyridine don't need to be
obtained. They are replaced with the very cheap
and easily available chemical calcium hydroxide.
Phenylacetic acid still is required in this method,
and as a List One chemical, it should never be
purchased
for a good phenylacetic acid recipe starting with
the common industrial solvent ethylbenzene.
To do the reaction, first one must make the cal-
cium salt of phenylacetic acid. To do this, put 500
grams of phenylacetic acid into a glass container.
Add about two quarts of a 50-50 mixture of de-
natured alcohol and water. This is the reaction
solvent. Stir and warm the mixture using a hot
water batch until all the phenylacetic acid has dis-
solved producing a clear water-like solution. Now
to this solution, add 135 grams of finely pow-
dered calcium hydroxide. It should be added
slowly with strong stirring of the solution. Heat
will be produced by the reaction to make calcium
phenylacetate, so take care that the mixture
doesn't boil during the addition.
Once all the calcium hydroxide has been added,
continue stirring for an additional hour, and allow
the mixture to cool. A white-colored precipitate
of calcium phenylacetate will have been formed.
This product should be filtered out, rinsed with
some water, then spread out to dry on wax paper
or clean dishes.
The next thing one needs is a reaction vessel to
produce phenylacetone from the calcium
phenylacetate. Luck is on our side here. It has
been found that iron and steel reaction vessels are
superior to glass when doing this reaction. They
don't need to be coated on the inside with any
protective paint. I would avoid the use of galva-
nized steel because the zinc metal coating may
interfere with the reaction. The reason why an
iron reaction pot is superior, is because it con-
ducts heat so well. The top of the reaction vessel
gets almost as hot as the bottom. In this way, the
phenylacetone formed and boiled out of the reac-
tion mixture doesn't condense on a cold top of the
pot and drip back into the reaction mixture. At
that point a lot of it would be destroyed
One starts with a steel or iron pot about as big
around as a large frying pan. It should measure in
height less than half the diameter of the pot.
Threads should be cut around the top of the pot,
and a flat iron or steel lid should be obtained with
threads that match the ones on the reaction pot.
Into the center of the lid, a hole should be drilled.
The hole should have at least a half-an-inch di-
ameter. Larger would be better to allow for easier
escape of the phenylacetone. A section of steel or
copper tubing should next be mated with that
central hole and welded into place. The tubing
should be bent so that it first rises a couple of
inches off the top of the pot, and then begins
sloping downward so that the cooled condensed
phenylacetone liquid will run towards the
phenylacetone collector.
The phenylacetone collector is a metal cup of
about one quart capacity. Towards the top on one
side, a threaded hole should be drilled in it which
matches the tubing used. In this way, the collector
can be screwed onto and off of the tubing. On the
opposite side of the collector, a smaller hole
should be drilled, and a nipple to which a vacuum
line can be attached should be screwed in. One
may want to put a section of water jacket around
the lower portion of the tubing to assure easy
condensing of the phenylacetone product. One
could get around this by wrapping some cloth
around the lower section of tubing, and keeping it
wet with cold water during the reaction. One
could also chill the collector vessel with an ice
bath.
Now the reaction is ready to be run. Take the
calcium phenylacetate, which was made earlier
(roughly 650 grams product), and stir it up to gether with about 900 grams of calcium acetate.
This will give about three moles of calcium ace-
tate for each mole of calcium phenylacetate. Now
take this rough mixture, and put about a cup full
at a time into a blender. Grind the mixture to-
gether while shaking the blender for about a min-
ute. When the dust has settled in the blender, pour
it into the reaction pot, and repeat the process
with another cup of the rough mixture. Continue
until the reaction pot is no more than a little over
half full. Fill no further because the mixture
froths at first while it is being heated.
Now screw the lid onto the reaction pot, attach
the collector vessel to the tubing, and begin heat-
ing the reaction pot. A natural-gas-fired ring
heater which will blow flames part way up the
sides of the reaction vessel is what was used in
the scientific papers. I suppose one could also
stick the reaction vessel into a pile of charcoal.
One wants to heat the pot to a temperature of
around 350° to 400° C. This is in the neighbor-
hood of 700° F or so. When the pot starts heating
up, attach the vacuum line to the vacuum nipple,
and apply a vacuum to the system. An aspirator
will give enough vacuum, and also flush the
fumes from the reaction down the drain. One of
the fumes is acetone. This flammable material is
not a good mixture with open flames. If one uses
a vacuum pump, make sure that its discharge port
vents fumes away from flame through some tub-
ing. The vacuum serves to help pull the product
out of the reaction pot and to the collector vessel.
It helps to eliminate the problem of product con-
densing and dripping back into the pot.
After about two hours of heating, the reaction
will be done. The heating can be stopped, the
vacuum removed, and then the collector vessel
unscrewed from the tubing. It should be roughly
half full of a brownish-colored liquid that is
mostly phenylacetone. A decent vacuum will pre-
vent much of any acetone from being collected. If
there isn't much of any product in the collector,
the heating wasn't strong enough. In this case, re-
heat the reaction pot with higher flames. In a
well-done reaction, there will be nothing left in
the reaction vessel except a solid residue of cal-
cium carbonate colored funky with some dark tar.
This can be cleaned out, and another production
is run.
The crude dark-colored phenylacetone product
obtained must be purified before it is used to
make meth. The simplest way to do this is to vac-
uum fractionally distill the mixture, just as de-
scribed earlier in this chapter. The alternative
method for getting pure phenylacetone from the
mixture is to steam distill out the phenylacetone.
The procedure for doing this is described in
Chapter Nine of this book.
One of the biggest hassles in doing this reaction
is the need to first convert the phenylacetic acid
to the calcium salt. I read a similar recipe in Or-
ganic Syntheses where they omitted that step. To
follow their procedure here, one would mix 500
grams of phenylacetic acid with 660 ml of glacial
acetic acid. When the two substances have mixed
together with stirring to form a clear solution,
then with stirring, slowly add 550 grams calcium
hydroxide to the mixture. In their procedure, they
then just added this reaction mush to the reaction
pot and cooked away. Does this work as well in
the case of making phenylacetone? Damned if I
know. I doubt I'll be trying it out anytime soon.
It's worth a try, though.
A somewhat similar procedure can be found in
the Journal of Organic Chemistry, Volume 28,
pages 880-882. In this method, phenylacetic acid,
acetic acid, and iron are heated together in chemi-
cal glassware to around 300° C. Phenylacetone
distills out and can be collected. Check out the
reference for more details.
ketone, or l-phenyl-2-propanone, is easy to make
if one can get the chemicals. In this reaction,
phenylacetic acid reacts with acetic anhydride
with pyridine catalysts to produce phenylacetone
plus carbon dioxide and water.
A Russian journal tells of using sodium acetate
instead of pyridine. For nearly two decades now,
I have let one sour experience with this reaction
convince me it is useless, an example of lying
commie science. I have been convinced that my
judgment on this Russian variation was prema-
ture, and it really does work. We'll talk more
about that method at the end of this chapter, but
first let's cover the version using pyridine. I have
done this reaction many times.
The reaction is done as follows: Into a clean,
dry 3000 ml round bottom flask is placed 200
grams of phenylacetic acid, 740 ml of acetic an-
hydride and 740 ml of pyridine. This is done on a
table covered with a sheet of newspaper, because
phenylacetic acid, once it is exposed to the air,
smells like cat urine, and the smell is next to im-
possible to get rid of. Pyridine also smells awful.
The pyridine and acetic anhydride are measured
out in a large glass measuring cup.
The flask is then gently swirled until the
phenylacetic acid is dissolved. The flask is then
assembled with the 50 cm condenser and the vac-
uum adapter, as shown in Figure 9. Before as-
sembly, the joints are lightly greased with sili-
cone-based stop cock grease. This prevents the
pieces from getting stuck together. All pieces
should be clean and dry. The vacuum nipple of
the vacuum adapter is plugged with a piece of
tape. In the rounded section of the vacuum
adapter is a plug of cotton, then about two tea-
spoons of Drierite (anhydrous calcium sulfate),
then another plug of cotton. This makes a bed of
Drierite, which is prevented from falling into the
flask by a ball of cotton. The purpose of this is to
keep moisture from the air away from the reac-
tion.
Now the underground chemist is ready to begin
heating the flask. Notice that in Figure 10, the
flask is in a large pan, which sits on the buffet
range. The pan is filled about half-full of cooking
oil (Wesson works fine). This is so that the flask
is heated evenly. The heat is turned about half
way to maximum, and the flow of cold water
through the condenser is begun. A length of plas-
tic or rubber tubing runs from the cold-water fau-
cet to the lower water inlet of the condenser. The
cold water runs through the condenser and out of
the top water exit, through another length of tub-
ing to the drain. In this way, the rising vapors
from the boiling pyridine are condensed and re-
turned to the flask. A rate of water flow of about
one gallon per minute is good.
Within a half hour, the flask is hot enough to
begin boiling. The heat is then turned down to
stabilize the flask at a gentle rate of boiling. This
is called a reflux. The boiling is allowed to con-
tinue for seven hours. During this time, the reac-
tion mixture turns from clear to brownish-red in
color. Periodically, the rate of water flow coming
out of the condenser is checked, because faucet washers tend to swell after a while and slow
down the rate of water flow.
After seven hours, the heat is turned off.
Twenty minutes after the boiling stops, the
glassware is set up as shown in Figure 11. The
cotton and Drierite are removed from the vacuum
adapter. Then four pea-sized pieces are broken
off a pumice foot stone (purchased at the local
pharmacy). These are called boiling chips, be-
cause they cause liquids to boil faster and more
evenly. They are added to the flask with the reac-
tion mixture in it. But they are not added until 20
minutes after the boiling stops; otherwise they
could produce a geyser of hot chemicals.
Now the heat is turned back on, a little hotter
than when refluxing the reaction mixture. Water
flow to the condenser is resumed. The mixture
soon begins boiling again and the vapors con-
dense in the condenser and flow to the collecting
round bottom flask. What is being boiled off is a
mixture of pyridine and acetic anhydride. The
phenylacetone remains behind in the distilling
round bottom flask, because its boiling point is
about 100 degrees Celsius higher than the pyri-
dine and acetic anhydride. This process is called
simple distillation. Distillation continues until
1300 ml has been collected in the collecting
round bottom flask, then the heat is turned off.
The 1300 ml is poured into a clean dry glass jug
about one gallon in size, which is then stoppered with a cork. Later in this chapter, I will describe a
process by which this pyridine is recycled for fu-
ture use. Since pyridine is so expensive, this cuts
production costs considerably.
What is left in the distilling round bottom flask
is a mixture of phenylacetone, some acetic anhy-
dride and pyridine, and a high-molecular-weight
tarry polymer, which is reddish-brown in color.
The next step is to isolate and purify the
phenylacetone.
The flask is taken out of the hot oil arid allowed
to cool down. Three-quarters of a gallon of 10%
sodium hydroxide solution (NaOH) is needed. So
a gallon-size glass jug is filled three-quarters full
of cold water and about 10 ounces of sodium hy-
droxide pellets are added to it. A good quality lye,
such as Red Devil or Hi-Test, is a substitute that
saves a good deal of money and works fine. Eye
protection is always worn when mixing this up. It
is mixed thoroughly by swirling, or by stirring
with a clean, wooden stick. The dissolution of
NaOH in water produces a great deal of heat. It is
allowed to cool off before the chemist proceeds.
About 500 ml of the 10% NaOH is put in a
1000 ml sep funnel, then the crude phenylacetone
mixture from the round bottom flask is poured in
the sep funnel also. The top of the sep funnel is
stoppered and mixed by swirling. When the fun-
nel gets hot, it is allowed to set for a while. Then
the mixing is continued, with the underground
chemist working his way up to shaking the sep
funnel, with his finger holding in the stopper.
What he is doing is removing and destroying the
acetic anhydride. Acetic anhydride reacts with the
sodium hydroxide solution to produce sodium
acetate, which stays dissolved in the water, never
to be seen again. Some of the pyridine and red-
colored tar also goes into the water. The destruc-
tion of the acetic anhydride is what produces the
heat.
After it has cooled down, about 100 ml of tolu-
ene is added to the sep funnel and shaken vigor-
ously for about 15 seconds. The sep funnel is un-
stoppered and allowed to sit in an upright position
for about one minute. The liquid in the funnel
will now have separated into two layers. On top is a mixture of toluene, phenylacetone, and red tar.
On the bottom is the water layer, which has some
phenylacetone in it. Pyridine is in both layers.
Two 500 ml Erlenmeyer flasks are placed on
the table, one marked "A," the other marked "B."
The stop cock on the sep funnel is opened, and
the water layer is drained into B. The top layer is
poured into A. B is poured back into the sep fun-
nel, and 50 ml of benzene is added. The funnel is
shaken for 15 seconds, then the water layer is
drained back into B. The top layer is poured into
A. The purpose of this is to get the phenylacetone
out of the water. Once again the water in B is put
in the sep funnel. Fifty ml of toluene is added,
and shaken. Xylene is for almost all purposes
substitutable for toluene, and is at present easier
to get at the hardware store. The water is drained
into B and the toluene layer poured into A. The
water in B is poured down the drain and the con-
tents of A put into the sep funnel along with 400
ml of 10% NaOH solution from the jug. After
shaking, the water layer is drained into B and the
toluene layer poured into A. The contents of B
are put back in the sep funnel and 50 ml of tolu-
ene added. After shaking, the chemist drains the
water layer into B and pours it down the drain.
The contents of A are added to the funnel again,
along with 400 ml of 10% NaOH solution; the
funnel is shaken again. The water layer is drained
into B and the toluene layer poured into A. The
contents of B are returned to the sep funnel, along
with 50 ml toluene, and shaken again. The water
layer is poured into B and poured down the drain.
The toluene layer is poured into A. The sep fun-
nel is washed out with hot water.
Now the last traces of pyridine are removed
from the phenylacetone. For this purpose, some
hydrochloric acid is needed. Hardware stores
usually have the 28% strength sometimes called
muriatic acid. A bottle in which the acid seems
clear-colored is used; the ones with a green tint
have been sitting around too long.
The contents of A are returned to the clean sep
funnel. Then 10 ml of hydrochloric acid, mixed
with 10 ml of water, is added to the sep funnel
and shaken for 30 seconds. The stopper is pulled out to check whether or not the odor of pyridine
has disappeared. If not, another 20 ml of the acid-
water mix is added and shaken. The odor should
now be gone, but if it is not, some more of the
mix is added and shaken. Now 200 ml of water is
added and shaken. Flask A is rinsed out with hot
water; the water layer is drained into B and
poured down the drain. The toluene layer is
poured into A. What has just been done is to con-
vert the pyridine into pyridine hydrochloride,
which dissolves in water, but not in toluene. It is
now down the drain.
Finally, for one last time, the contents of A are
returned to the sep funnel, along with 200 ml of
the 10% NaOH solution. This is shaken and the
water layer drained into B. The toluene layer is
allowed to stay in the sep funnel for the time be-
ing; more water will slowly fall out to the area of
the stop cock, where it can be drained out. It is
now ready to be distilled, and stray water must be
removed beforehand.
which an underground chemist can make
himself. The claisen adapter is checked to make
sure it is clean and dry. A clear glass beer bottle
is washed out with hot water, then smashed on
the cement floor. A few pieces are picked out that
are small enough to fit in the lower opening of the
claisen, yet big enough that they will not fall out of the bottom opening of the claisen adapter.
Pieces of the broken bottle are dropped in the
lower opening until that section of the claisen
adapter is filled to about the level shown in the
drawing. The chemist tries to get it to land in a
jumbled pattern, as shown in the drawing. Then
more similarly sized pieces of glass are dropped
in the upper opening of the claisen adapter until it
is filled to the level shown. Again a jumbled pat-
tern is striven for. The lower opening is then
stoppered with the proper size of glass or rubber
stopper. Finally, the outside is wrapped with a
layer or two of aluminum foil, except for the
ground glass joint.
The underground chemist will now distill the
phenylacetone. First, here is some information on
the process to be performed. The crude
phenylacetone the underground chemist has is a
mixture of toluene, phenylacetone, red tarry
polymer, some water and maybe some dibenzyl
ketone. These substances all have very different
boiling temperatures. By distilling this mixture
through a fractionating column, the chemist can
separate them very effectively and get a high-pu-
rity product. The way it works is easy to under-
stand. The vapors from the boiling mixture in the
distilling flask rise up into the fractionating col-
umn and come into contact with the pieces of
glass inside. Here the vapors are separated ac-
cording to boiling point. The substance in the
mixture with the lowest boiling point is able to
pass on through, while the other substances are
condensed and flow back into the distilling flask.
This is why the pieces of glass in the column
can't be tightly packed, as that would interfere
with the return flow, leading to a condition called
flooding. Once all of the lowest-boiling substance
has been distilled, the substance with the next
higher boiling point can come through the frac-
tionating column. In the distillation process to be
described, the order is as follows: toluene-water
azeotrope, 85° C; toluene, 110° C; phenylacetone,
120-130° C (under a vacuum of about 20 torr).
Why must the phenylacetone be distilled under
a vacuum? Because its boiling point at normal pressure is 216° C, which is much too hot. Dis-
tilling it at that temperature would ruin the prod-
uct. By distilling it under a vacuum, it boils at a
much lower temperature. The exact temperature
depends on how strong the vacuum is; the
stronger the vacuum, the lower the temperature.
For example, at a vacuum of 13 torr, the boiling
point goes down to about 105° C.
The glassware is set up as shown in Figure 13.
The distilling flask is no more than
2/3 full. If the
underground chemist has more crude phenylace-
tone than that, he has to wait until some of the
toluene has distilled off, then turns off the heat,
waits until the boiling stops and adds the rest of it
to the distilling flask.
The glassware should be clean and dry. A fast
way to dry glassware after washing is to put it in
the oven at 400° F for 20 minutes. Rubber stop-
pers do not go in the oven. Water tends to stay in-
side round bottom flasks dried in this way. So,
while they are still hot, the chemist takes a piece
of glass tubing and puts it inside the flask. He
sucks the moist air out of the flask with the glass
tubing before it has a chance to cool down and
condense. For the distillation, two 250 ml round
15
bottom flasks are needed, one to collect the tolu-
ene in, the other to collect the phenylacetone in.
Five boiling chips are put in the distilling flask.
The heat source is turned on, to the low range,
about 1/4 maximum. Water must be flowing
through the shorter condenser at about one gallon
per minute. When the mixture has begun boiling,
the heat is adjusted so that about one or two drops
per second drip into the collecting flask. The
temperature on the thermometer should say about
68° C. For accurate temperature readings
The material distilling at 85° C is the toluene-
water azeotrope. It is about 80% toluene and 20%
water. It is milky white from suspended droplets
of water. Once the water is all gone, pure toluene
is distilled at about 80° C. It is clear in color. If
the liquid in the collecting flask is not clear or
white in color, then undistilled material is being
carried over from the distilling flask. This is
caused either by having the distilling flask too
full or by having the heat turned too high. In ei-
ther case, the chemist must correct accordingly
and redistill it. Once the temperature reaches 115°
C on the thermometer, or the rate of toluene ap-
pearing in the collecting flask slows to a crawl, the heat is turned off because the chemist is ready
to vacuum distill the phenylacetone.
There is a problem that is sometimes encoun-
tered while distilling off the toluene. Sometimes
the toluene in the distilling flask will foam up in
the distilling flask instead of boiling nicely. These
bubbles refuse to break and they carry undistilled
material along with them to the collecting flask,
leaving a red liquid over there. This cannot be
allowed to happen. One effective method of
dealing with this is to turn on the water supply to
the aspirator at a slow rate so that a weak vacuum
is produced. Then the vacuum hose is attached to
the vacuum adapter and a weak vacuum produced
inside the glassware. This causes the bubbles to
break. Every few seconds, the vacuum hose is
removed, then reattached. In a while, the toluene
begins to boil normally and the vacuum can be
left off.
After it has cooled off, the collected distilled
toluene is poured into a labeled glass bottle. It can
be used again in later batches of phenylacetone.
The same 250 ml round bottom flask is reattached
to the collecting side, and the vacuum hose at-
tached to the vacuum adapter. The vacuum source
is turned on. If an aspirator is being used, the
water is turned all the way on. All the pieces of
glassware must be fitted snugly together. A
strong vacuum quickly develops inside the glass-
ware. The heat is turned on to about
]/3 maxi-
mum. The boiling begins again. At first, what
distills over are the last remnants of toluene and
water left in the distilling flask. Then the tem-
perature shown on the thermometer begins to
climb. The phenylacetone begins to distill. When
the thermometer reaches 100° C, the vacuum
hose is removed and the collecting 250 ml flask is
replaced with the clean, dry 250 ml flask, then the
vacuum hose is reattached. If a good vacuum
pump is being used, the flasks are changed at
about 80° C. This flask changing is done as fast
as possible to prevent the material in the distilling
flask from getting too hot during the change over.
If it gets too hot, it distills too rapidly when the
vacuum is reapplied, resulting in some red tar
being carried over along with it.
The vacuum is reapplied, and the phenylace-
tone is collected. With a properly working aspi-
rator, the phenylacetone will all be collected once
the temperature on the thermometer reaches 140-
150° C. With a good vacuum pump, it will all
come over by the time the temperature reaches
110-115° C. Once it is all collected, the heat is
turned off, the vacuum hose is removed from the
vacuum adapter and the vacuum source is turned
off.
The yield is about 100 ml of phenylacetone. It
should be clear to pale yellow in color. It has a
unique but not unpleasant smell. The flask hold-
ing this product is stoppered and stored upright in
a safe place. Although phenylacetone can be
stored in a freezer to keep it fresh, the chemist now proceeds to making N-methylformamide.
Once the distilling flask has cooled down, the
glassware is taken apart and cleaned. The red tar
left in the distilling flask and the fractionating
column is rinsed out with rubbing alcohol. Then hot soapy water is used on all pieces. A long, nar-
row brush comes in handy for this.
One last word about vacuum distillation. To
keep the vacuum strong, the vacuum hose is no
more than three feet long. This forces the chemist
to do the distilling close to the source of the vac-
uum.
Now for that pyridine recycling process I men-
tioned earlier in this chapter. After the under-
ground chemist has made a few batches of
phenylacetone, he will have accumulated a fair
amount of pyridine-acetic anhydride mixture in
the gallon-sized glass jug. He will now fraction-
ally distill it to recover the pyridine from it. The
clean dry glassware is set up as shown in Figure
15. It has a long fractionating column instead of
the short type just used. This is because pyridine
and acetic anhydride are harder to separate, so a
longer column is needed to do the job.
The distilling flask is a 3000 ml round bottom
flask with 5 boiling chips in it. The chemist pours
2000 ml of the acetic anhydride-pyridine mixture
into it. The heat is turned on to about '/3 maxi-
mum and the cold water is started flowing slowly
through the condenser. Within a half hour, the
mixture will begin to boil. A couple of minutes
later, the vapors will have worked their way
through the fractionating column and begin ap-
pearing in the 2000 ml collecting flask. The heat
source is adjusted so that it is collecting at the
rate of one or two drops per second. Distilling is
continued until 1000 ml have accumulated in the
collecting flask. If the temperature reading on the
thermometer goes above 135° C, the heat is
turned down a little to slow the rate of distillation.
Once 1000 ml has been collected, the heat is
turned off and it is allowed to cool down. After it
is cool, the distilling flask is removed and its
contents (mainly acetic anhydride) poured down
the drain. The contents of the collecting flask
(mainly pyridine) are poured into a clean, dry
2000 ml round bottom flask with 5 boiling chips,
or 5 boiling chips are simply added to the 2000
ml round bottom flask that the pyridine collected
in and that flask is put on the distilling side in
place of the 3000 ml flask. A clean, dry 1000 ml
17
round bottom flask is put on the collecting side.
The heat is turned back on and in a while the dis-
tilling begins again. As before, the rate of distil-
lation is adjusted to one or two drops per second.
The distillation is continued until 750 ml of pyri-
dine has been collected. Sometimes it does not
keep well, but so long as it is used to make an-
other batch of phenylacetone within a few hours
after it is made, this pyridine works just as well as
new pyridine.
Now let's talk about the Russian recipe, and
how I messed it up when I was a neophyte cooker
20 years ago, and the right way to do it. The Rus-
sian recipe, which dates to about 1940 during the
height of Stalin's wackiness when all sorts of po-
litically motivated "science" was turned out by
people fearing losing their lives if they didn't get
the "politically correct" results, calls for mixing
420 grams of phenylacetic acid with 700 ml of
acetic anhydride and 210 grams of sodium acetate
in a 2000 ml flask. Two advantages are obvious
here. The expensive reagent pyridine has been re-
placed with the cheap chemical sodium acetate.
Also, the reaction is being done considerably
more concentrated than with the pyridine recipe,
i.e., more phenylacetic acid is getting poured into
the 2000 ml flask, so more phenylacetone will be
produced at a single cooking session.
Back in, I think it was 1979, I tried this recipe
using a standard round bottom flask, which I just
set upon a magnetic stirrer hot plate, and began to
cook. Just setting a round bottom flask on a hot
plate surface is a poor way to heat this flask. I had
to turn the heat up to maximum just to get it to
start to boil. Shortly thereafter, the magnetic stir-
rer motor burned out from all the heat from the
hot plate, and the sodium acetate just sat at the
bottom of the flask with the weak boiling I was
making. At the end of the 18 hours of prescribed
cooking, I got maybe a 20% yield of product, and
was soured on this method for 20 years.
Now for the right way to do this reaction. First
of all, an oil bath or heating mantle should be
used to heat the reaction flask, because a weak
and puny boil isn't sufficient. The reaction mix-
ture must reach 145-150° C. Acetic anhydride
boils at 139° C, but with the higher boiling
phenylacetic acid mixed into the solution, and
similarly high boiling point phenylacetone being
produced, it's not too hard to make the solution
reach this temperature if it is being boiled good
and hard. With a good hard boil like that, just one
condenser isn't enough. One must use a three-
necked flask, and attach a condenser on two of
the necks, and plug the third neck with a glass
stopper No stirrer is really necessary with this reaction,
as the strong boil will lift sodium acetate off the
bottom of the flask, and mix it with the solution.
Three-necked flasks are a bitch to get these days,
but stainless steel is fine for this reaction, as is a
Teflon-coated metal replica. As an added bonus,
using metal replicas makes it impossible to bust
one for having glassware for the purpose of
making meth, a 10-year felony under the Meth
Act of 1996. Drying tubes should be attached to
the tops of the condensers, as in the example us-
ing pyridine.
Heat the oil to about 160° C or so to get a good
boiling inside the flask, and let cook for 18 hours.
At the end of the cook, allow the flask to cool,
then pour the reaction mixture into a gallon of
cold water. Phenylacetone will float on top of the
water, and the acetic anhydride and sodium ace-
tate will stay in the water.
Using a sep funnel, separate off the
phenylacetone from the water, and pour it into a
convenient container. Now extract the water layer
with two 200 ml portions of toluene, and add
these extracts to the phenylacetone. The water
can now be thrown away. The combined
phenylacetone and toluene extracts should next
be poured into a large sep funnel, and washed two
times with 500 ml portions of 5% sodium hy-
droxide or lye solution in water. This will destroy
any acetic anhydride left floating around.
The toluene solution containing the
phenylacetone is poured into a beaker, and al-
lowed to sit for a few hours. Some water will fall
out of the solution, and sit on the bottom of the
beaker.
Next, the toluene solution containing the
phenylacetone is poured into a distilling flask,
and a distillation is done, just like in the recipe
using pyridine. First, the toluene-water azeotrope
distills, drying the mixture, then pure toluene dis-
tills. The toluene can be reused. When the toluene
has distilled, the mixture is allowed to cool some
before commencing vacuum distillation of the
phenylacetone. The Russians would have you be-
lieve that about 400 ml of phenylacetone will re-
sult from the cook. I have been told by people in
a position to know that 300-350 ml is more likely.
Not a bad day's work, by any means.
An alternative procedure for making
phenylacetone from phenylacetic acid can be
found in The Journal of the Society of Chemical
Industry, Volume 44, pages 109-112 (1925) and
in the Journal of the Chemical Society, Volume
59, pages 621-629 (1891). In this method, the
calcium salts of phenylacetic acid and acetic acid
are mixed together and then heated. The product
we want, phenylacetone, distills out of the reac-
tion mixture. The advantage to this method is that
acetic anhydride and pyridine don't need to be
obtained. They are replaced with the very cheap
and easily available chemical calcium hydroxide.
Phenylacetic acid still is required in this method,
and as a List One chemical, it should never be
purchased
for a good phenylacetic acid recipe starting with
the common industrial solvent ethylbenzene.
To do the reaction, first one must make the cal-
cium salt of phenylacetic acid. To do this, put 500
grams of phenylacetic acid into a glass container.
Add about two quarts of a 50-50 mixture of de-
natured alcohol and water. This is the reaction
solvent. Stir and warm the mixture using a hot
water batch until all the phenylacetic acid has dis-
solved producing a clear water-like solution. Now
to this solution, add 135 grams of finely pow-
dered calcium hydroxide. It should be added
slowly with strong stirring of the solution. Heat
will be produced by the reaction to make calcium
phenylacetate, so take care that the mixture
doesn't boil during the addition.
Once all the calcium hydroxide has been added,
continue stirring for an additional hour, and allow
the mixture to cool. A white-colored precipitate
of calcium phenylacetate will have been formed.
This product should be filtered out, rinsed with
some water, then spread out to dry on wax paper
or clean dishes.
The next thing one needs is a reaction vessel to
produce phenylacetone from the calcium
phenylacetate. Luck is on our side here. It has
been found that iron and steel reaction vessels are
superior to glass when doing this reaction. They
don't need to be coated on the inside with any
protective paint. I would avoid the use of galva-
nized steel because the zinc metal coating may
interfere with the reaction. The reason why an
iron reaction pot is superior, is because it con-
ducts heat so well. The top of the reaction vessel
gets almost as hot as the bottom. In this way, the
phenylacetone formed and boiled out of the reac-
tion mixture doesn't condense on a cold top of the
pot and drip back into the reaction mixture. At
that point a lot of it would be destroyed
One starts with a steel or iron pot about as big
around as a large frying pan. It should measure in
height less than half the diameter of the pot.
Threads should be cut around the top of the pot,
and a flat iron or steel lid should be obtained with
threads that match the ones on the reaction pot.
Into the center of the lid, a hole should be drilled.
The hole should have at least a half-an-inch di-
ameter. Larger would be better to allow for easier
escape of the phenylacetone. A section of steel or
copper tubing should next be mated with that
central hole and welded into place. The tubing
should be bent so that it first rises a couple of
inches off the top of the pot, and then begins
sloping downward so that the cooled condensed
phenylacetone liquid will run towards the
phenylacetone collector.
The phenylacetone collector is a metal cup of
about one quart capacity. Towards the top on one
side, a threaded hole should be drilled in it which
matches the tubing used. In this way, the collector
can be screwed onto and off of the tubing. On the
opposite side of the collector, a smaller hole
should be drilled, and a nipple to which a vacuum
line can be attached should be screwed in. One
may want to put a section of water jacket around
the lower portion of the tubing to assure easy
condensing of the phenylacetone product. One
could get around this by wrapping some cloth
around the lower section of tubing, and keeping it
wet with cold water during the reaction. One
could also chill the collector vessel with an ice
bath.
Now the reaction is ready to be run. Take the
calcium phenylacetate, which was made earlier
(roughly 650 grams product), and stir it up to gether with about 900 grams of calcium acetate.
This will give about three moles of calcium ace-
tate for each mole of calcium phenylacetate. Now
take this rough mixture, and put about a cup full
at a time into a blender. Grind the mixture to-
gether while shaking the blender for about a min-
ute. When the dust has settled in the blender, pour
it into the reaction pot, and repeat the process
with another cup of the rough mixture. Continue
until the reaction pot is no more than a little over
half full. Fill no further because the mixture
froths at first while it is being heated.
Now screw the lid onto the reaction pot, attach
the collector vessel to the tubing, and begin heat-
ing the reaction pot. A natural-gas-fired ring
heater which will blow flames part way up the
sides of the reaction vessel is what was used in
the scientific papers. I suppose one could also
stick the reaction vessel into a pile of charcoal.
One wants to heat the pot to a temperature of
around 350° to 400° C. This is in the neighbor-
hood of 700° F or so. When the pot starts heating
up, attach the vacuum line to the vacuum nipple,
and apply a vacuum to the system. An aspirator
will give enough vacuum, and also flush the
fumes from the reaction down the drain. One of
the fumes is acetone. This flammable material is
not a good mixture with open flames. If one uses
a vacuum pump, make sure that its discharge port
vents fumes away from flame through some tub-
ing. The vacuum serves to help pull the product
out of the reaction pot and to the collector vessel.
It helps to eliminate the problem of product con-
densing and dripping back into the pot.
After about two hours of heating, the reaction
will be done. The heating can be stopped, the
vacuum removed, and then the collector vessel
unscrewed from the tubing. It should be roughly
half full of a brownish-colored liquid that is
mostly phenylacetone. A decent vacuum will pre-
vent much of any acetone from being collected. If
there isn't much of any product in the collector,
the heating wasn't strong enough. In this case, re-
heat the reaction pot with higher flames. In a
well-done reaction, there will be nothing left in
the reaction vessel except a solid residue of cal-
cium carbonate colored funky with some dark tar.
This can be cleaned out, and another production
is run.
The crude dark-colored phenylacetone product
obtained must be purified before it is used to
make meth. The simplest way to do this is to vac-
uum fractionally distill the mixture, just as de-
scribed earlier in this chapter. The alternative
method for getting pure phenylacetone from the
mixture is to steam distill out the phenylacetone.
The procedure for doing this is described in
Chapter Nine of this book.
One of the biggest hassles in doing this reaction
is the need to first convert the phenylacetic acid
to the calcium salt. I read a similar recipe in Or-
ganic Syntheses where they omitted that step. To
follow their procedure here, one would mix 500
grams of phenylacetic acid with 660 ml of glacial
acetic acid. When the two substances have mixed
together with stirring to form a clear solution,
then with stirring, slowly add 550 grams calcium
hydroxide to the mixture. In their procedure, they
then just added this reaction mush to the reaction
pot and cooked away. Does this work as well in
the case of making phenylacetone? Damned if I
know. I doubt I'll be trying it out anytime soon.
It's worth a try, though.
A somewhat similar procedure can be found in
the Journal of Organic Chemistry, Volume 28,
pages 880-882. In this method, phenylacetic acid,
acetic acid, and iron are heated together in chemi-
cal glassware to around 300° C. Phenylacetone
distills out and can be collected. Check out the
reference for more details.
I prefer the first method if you can find thorium or manganese oxides.
Because the second method is very long and you have to be very careful not to make mistakes, but at the same time it is very practical because it is obtained from cheaper and easier raw materials.
I have sent the second method in full, judge for yourself which one you are more comfortable with.
Instead of pyridine in the second method, you can use sodium acetate.
Because the second method is very long and you have to be very careful not to make mistakes, but at the same time it is very practical because it is obtained from cheaper and easier raw materials.
I have sent the second method in full, judge for yourself which one you are more comfortable with.
Instead of pyridine in the second method, you can use sodium acetate.