G.Patton

Well-known member
Expert
Joined
Jul 5, 2021
Messages
1,685
Solutions
3
Reaction score
1,076
Points
113
Deals
1

Introduction
Vt5cdTuK2V

Fenethylline (BAN, USAN) is a codrug of amphetamine and theophylline and a prodrug to both. It is also spelled phenethylline and fenetylline (INN); other names for it are amphetaminoethyltheophylline and amfetyline. The drug was marketed for use as a psychostimulant under the brand names Captagon, Biocapton, and Fitton.

Synthesis of Fenethylline is quite simple and doesn't take elaborated expensive glassware. In this topic, you can find two-step synthesis of this substance, each step presented by two different methods, which have some features.

One of the main advantages of fenethylline was that it does not tend to increase blood pressure to the same extent as amphetamines, and so it could be used in patients with cardiovascular conditions. Fenethylline is metabolized by the body to form two drugs amphetamine (24.5% of oral dose) and theophylline (13.7% of oral dose), both of which are active stimulants themselves. The physiological effects of fenethylline therefore result from a combination of all three drugs.

Difficulty rating: 4/10

Equipment and glassware:
  • Magnetic stirrer with heater;
  • Filter paper;
  • pH Indicator paper;
  • Vacuum source;
  • Buchner flask and funnel [Schott filter may be used for small quantities];
  • Reflux condenser;
  • Oil bath;
  • Funnel;
  • 250 or 500 mL Separatory funnel;
  • Laboratory scale (0.01-100 g is suitable) [depends on synthesis load];
  • Retort stand and clamp for securing apparatus;
  • [Method 1_1]
    • 50 mL Round-bottom flask (RBF);
  • [Method 2_1]
    • 1 L Round-bottom flask (RBF);
  • [Method 1_2]
    • 1 L Round-bottom flask (RBF);
  • [Method 2_2]
    • 5 mL Pear shaped flask;
  • Flash chromatography kit

Reagents:
  • Theophylline (1);
  • 1,2-dichloroethane (2);
  • Distilled water;
  • 1-phenyl-2-aminopropane (4);
  • Sodium sulfate (Na2SO4) anhydrous;
  • [Method 1_1]
    • Aliquat-336 or TEBA (BTEAC) or TBAB (catalyst);
    • Petroleum ether;
  • [Method 2_1]
    • Sodium hydroxide;
    • i-Propanol (IPA);
    • Chloroform;
    • Ethanol (EtOH);
  • [Method 1_2]
    • Alcohol (EtOH) or toluene;
    • Hydrochloric acid (HCl) alcoholic solution;
  • [Method 2_2]
    • Sodium bicarbonate (aq. solution);
    • Dichloromethane;
    • Ethyl acetate;
FxPlLdXBbK
Fenethylline [3,7-Dihydro-1,3-dimethyl-7-[2-[(1-methyl-2-phenylethyl)amino]ethyl]-1H-purine-2,6-dione]
Boiling Point: 563.8 °C at 760 mm Hg;
Melting Point: 227–229 °C;
Molecular Weight: 341.41 g/mol;
Density: 1.26±0.1 g/cm3;
CAS Number: 3736-08-1.



7-(2-Chloroethyl)theophylline from Theophylline

O2W5vxYl0w
Method 1_1
Theophylline (1) (10 mmol), finely ground sodium (potassium) hydroxide (10–20 mmol) and aliquat-336 (0.6 mmol) are suspended in 1,2-dichloroethane (2) (10–20 ml) in 50 mL Round-bottom flask (RBF) with reflux condenser. The reaction mixture is stirred under reflux for 4 hours, filtered while hot and the precipitate dissolved in distilled water and the solution neutralized to pH 7 to give the unreacted theophylline and the synthesized symmetric 1,2-bis(7-theophyllinyl)ethane. Trituration of the taken to dryness filtrate under reduced pressure with petroleum ether or water affords the desired chloroalkyl derivative (3) in crystalline form in 99 % yield from the theoretical. The compound (3) obtained are then recrystallized from ethanol.

Aliquat-336, TEBA (BTEAC) and TBAB show similar catalytic activities.

Method 2_1
Theophylline (1) (150.0 mmol, 29.70 g) was added to a solution of sodium hydroxide (150.0 mmol, 6.0 g) in 200 ml water in 1 L Round-bottom flask (RBF). 1,2-Dichloroethane (1.20 mol, 118.66 g) in 300 ml i-propanol was then added with stirring. The mixture was heated under reflux at 78–80 °C for 76.5 h. After filtration and removal of the solvent, the residual solid was extracted with chloroform (3 x 200 ml). Combined chloroform extracts were dried over anhydrous sodium sulfate and after filtration the solvent was removed. The product (3) crystallized from ethanol in 90 % yield, m.p.: 120–122 °C.

1,3-dimethyl-7-[2-(1-phenylpropan-2-ylamino)ethyl]purine-2,6-dione (Fenethylline) from 7-(2-Chloroethyl)theophylline and 1-Phenyl-2-aminopropane (amphetamine)

R9LsQxilbj
Method 1_2
1 mol of 7-(2-Chloroethyl)theophylline (3) and 2.5 mols of 1-phenyl-2-aminopropane (4) are heated for 6 hours in an oil bath in 1 L Round-bottom flask (RBF), if necessary with addition of alcohol or toluene. The reaction mixture is diluted with alcohol and acidified with alcoholic hydrochloric acid. The crystalline mass formed is filtered with suction and extracted by boiling with alcohol. A product having a melting point of 237 to 239 °C is formed. With prolonged extraction by boiling with alcohol, the melting point of the mass falls, preferably due to a change in modification, to 227 to 229 °C. However, analysis shows that both products are the pure condensation product. Instead of the chloroethyl theophylline, it is also possible to use the corresponding bromine derivative. It was found that in this way the process is facilitated, and the yield is improved.

Method 2_2
A mixture of 7-(2-Chloroethyl)theophylline (3) (0.22 g, 0.9 mmol) and 1-phenyl-2-aminopropane (4) (0.49 g, 3.6 mmol) was heated at 100 °C for 17 h in 5 mL pear shaped flask. After cooling to room temperature, the saturated aqueous solution of sodium bicarbonate was added to basify the reaction mixture to a pH of 8. The aqueous phase was extracted with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate. Filtration and concentration yielded a residue, which was purified by flash column chromatography using silica gel as the stationary phase and ethyl acetate as the mobile phase to produce compound (5) (0.15 g, 0.4 mmol). Yield: 48 %.
 
Last edited:

thedrugdesigner

New member
Joined
Jun 5, 2022
Messages
1
Reaction score
1
Points
3
even better if enantiopure dAMP is used instead of racemic dlAMP :)
great post man.
 

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
Thank you for the explanation, but is there a video of the process for the benefit of everyone and beginners like me? Thank you
 

quite

New member
Joined
Jun 4, 2022
Messages
2
Reaction score
1
Points
3

IntroductionView attachment 5168

Fenethylline (BAN, USAN) is a codrug of amphetamine and theophylline and a prodrug to both. It is also spelled phenethylline and fenetylline (INN); other names for it are amphetaminoethyltheophylline and amfetyline. The drug was marketed for use as a psychostimulant under the brand names Captagon, Biocapton, and Fitton.

Synthesis of Fenethylline is quite simple and doesn't takes elaborated expensive glassware. In this topic you can find two step synthesis of this substance, each step presented by two different methods, which have some features.

One of the main advantages of fenethylline was that it does not tend to increase blood pressure to the same extent as amphetamines and so could be used in patients with cardiovascular conditions. Fenethylline is metabolized by the body to form two drugs amphetamine (24.5% of oral dose) and theophylline (13.7% of oral dose), both of which are active stimulants themselves. The physiological effects of fenethylline therefore result from a combination of all three drugs.

Difficulty rating: 4/10

Equipment and glassware:
  • Magnetic stirrer with heater;
  • Filter paper;
  • pH Indicator paper;
  • Vacuum source;
  • Buchner flask and funnel [Schott filter may be used for small quantities];
  • Reflux condenser;
  • Oil bath;
  • Funnel;
  • 250 or 500 mL Separatory funnel;
  • Laboratory scale (0.01-100 g is suitable) [depends on synthesis load];
  • Retort stand and clamp for securing apparatus;
  • [Method 1_1]
    • 50 mL Round-bottom flask (RBF);
  • [Method 2_1]
    • 1 L Round-bottom flask (RBF);
  • [Method 1_2]
    • 1 L Round-bottom flask (RBF);
  • [Method 2_2]
    • 5 mL Pear shaped flask;
  • Flash chromatography kit

Reagents:
  • Theophylline (1);
  • 1,2-dichloroethane (2);
  • Distilled water;
  • 1-phenyl-2-aminopropane (4);
  • Sodium sulfate (Na2SO4) anhydrous;
  • [Method 1_1]
    • Aliquat-336 or TEBA (BTEAC) or TBAB (catalyst);
    • Petroleum ether;
  • [Method 2_1]
    • Sodium hydroxide;
    • i-Propanol (IPA);
    • Chloroform;
    • Ethanol (EtOH);
  • [Method 1_2]
    • Alcohol (EtOH) or toluene;
    • Hydrochloric acid (HCl) alcoholic solution;
  • [Method 2_2]
    • Sodium bicarbonate (aq. solution);
    • Dichloromethane;
    • Ethyl acetate;
Fenethylline [3,7-Dihydro-1,3-dimethyl-7-[2-[(1-methyl-2-phenylethyl)amino]ethyl]-1H-purine-2,6-dione]
Boiling Point: 563.8 °C at 760 mm Hg;
Melting Point: 227–229 °C;
Molecular Weight: 341.41 g/mol;
Density: 1.26±0.1 g/cm3;
CAS Number: 3736-08-1 .



7-(2-Chloroethyl)theophylline from Theophylline

Method 1_1
Theophylline (1) (10 mmol), finely ground sodium (potassium) hydroxide (10–20 mmol) and aliquat-336 (0.6 mmol) are suspended in 1,2-dichloroethane (2) (10–20 ml) in 50 mL Round-bottom flask (RBF) with reflux condenser. The reaction mixture is stirred under reflux for 4 hours, filtered while hot and the precipitate dissolved in distilled water and the solution neutralized to pH 7 to give the unreacted theophylline and the synthesized symmetric 1,2-bis(7-theophyllinyl)ethane. Trituration of the taken to dryness filtrate under reduced pressure with petroleum ether or water affords the desired chloroalkyl derivative (3) in crystalline form in 99 % yield from the theoretical. The compound (3) obtained are then recrystallized from ethanol.

Aliquat-336, TEBA (BTEAC) and TBAB show similar catalytic activities.

Method 2_1
Theophylline (1) (150.0 mmol, 29.70 g) was added to a solution of sodium hydroxide (150.0 mmol, 6.0 g) in 200 ml water in 1 L Round-bottom flask (RBF). 1,2-Dichloroethane (1.20 mol, 118.66 g) in 300 ml i-propanol was then added with stirring. The mixture was heated under reflux at 78–80 °C for 76.5 h. After filtration and removal of the solvent, the residual solid was extracted with chloroform (3 x 200 ml). Combined chloroform extracts was dried over anhydrous sodium sulfate and after filtration the solvent was removed. The product (3) crystallized from ethanol in 90 % yield, m.p.: 120–122 °C.

1,3-dimethyl-7-[2-(1-phenylpropan-2-ylamino)ethyl]purine-2,6-dione (Fenethylline) from 7-(2-Chloroethyl)theophylline and 1-Phenyl-2-aminopropane (amphetamine)

Method 1_2
1 mol of 7-(2-Chloroethyl)theophylline (3) and 2.5 mols of 1-phenyl-2-aminopropane (4) are heated for 6 hours in an oil bath in 1 L Round-bottom flask (RBF), if necessary with addition of alcohol or toluene. The reaction mixture is diluted with alcohol and acidified with alcoholic hydrochloric acid. The crystalline mass formed is filtered with suction and extracted by boiling with alcohol. A product having a melting point of 237 to 239 °C is formed. With prolonged extraction by boiling with alcohol, the melting point of the mass falls, preferably due to a change in modification, to 227 to 229 °C. However, analysis shows that both products are the pure condensation product. Instead of the chloroethyl theophylline, it is also possible to use the corresponding bromine derivative. It was found that in this way the process is facilitated and the yield is improved.

Method 2_2
A mixture of 7-(2-Chloroethyl)theophylline (3) (0.22 mg, 0.9 mmol) and 1-phenyl-2-aminopropane (4) (0.49 g, 3.6 mmol) was heated at 100 °C for 17 h in 5 mL pear shaped flask;. After cooling to room temperature, the saturated aqueous solution of sodium bicarbonate was added to basify the reaction mixture to a pH of 8. The aqueous phase was extracted with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate. Filtration and concentration yielded a residue, which was purified by flash column chromatography using silica gel as the stationary phase and ethyl acetate as the mobile phase to produce compound (5) (0.15 g, 0.4 mmol). Yield: 48 %.
G.PattonThanks sir, you are GREAT!
 

G.Patton

Well-known member
Expert
Joined
Jul 5, 2021
Messages
1,685
Solutions
3
Reaction score
1,076
Points
113
Deals
1
Thank you for the explanation, but is there a video of the process for the benefit of everyone and beginners like me? Thank you
cyb3r0Right now, we don't have a video tutorial, it's not popular synthesis.
 
Last edited by a moderator:

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
THEOPHYLLINE (ANHYDROUS) 99% 100GM/BTL. (C7H8N4O2, 1,3-DIMETHYLXANTHINE)


Is this required?
 

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
My friend, honestly we haven't understand yet. You mentioned that there are two ways and each way has special reagents.

Are the two methods mandatory to move from the first to the second or are they optional?

And please write the steps in an orderly manner.

And he hates you
 

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
My friend, honestly we haven't understand yet. You mentioned that there are two ways and each way has special reagents.

Are the two methods mandatory to move from the first to the second or are they optional?

And please write the steps in an orderly manner.

And he hates you
cyb3r0Reminder
 

G.Patton

Well-known member
Expert
Joined
Jul 5, 2021
Messages
1,685
Solutions
3
Reaction score
1,076
Points
113
Deals
1
And he hates you
cyb3r0Thank you. This method clearly explain that you can choose appropriate method for you in each step. I cannot explain more clearly, maybe you have problem not with my article...
Method 1_1 and Method 1_2
or
Method 2_1 and Method 2_2
or
Method 1_1 and Method 2_2
or
Method 2_1 and Method 1_2
Do you understand now???
 

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
What are the percentages of reagents in grams?
 

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
Can I use any other solvent for this step?
Because the ether is not available to me, there is no suitable alternative that performs the same task. Thank you
taken to dryness filtrate under reduced pressure with petroleum ether or water affords the desired chloroalkyl derivative
G.Patton
 

MadHatter

Well-known member
Joined
Dec 4, 2021
Messages
442
Solutions
1
Reaction score
301
Points
63
Thank you for an excellent write-up as usual!
But I can't really see the point of the drug itself? Why ingest a prodrug that gives you a minor amount of speed and a pretty useless asthma medication? Theophylline has no psychostimulating effects I'm aware of, and I know the medicaton quite well.
 

G.Patton

Well-known member
Expert
Joined
Jul 5, 2021
Messages
1,685
Solutions
3
Reaction score
1,076
Points
113
Deals
1
DocXTheophylline or Fenethylline? :unsure: Fenethylline is works as stimulator but not so potent then amph. Some people ask about this synthesis.
 

MadHatter

Well-known member
Joined
Dec 4, 2021
Messages
442
Solutions
1
Reaction score
301
Points
63
Theophylline or Fenethylline? :unsure: Fenethylline is works as stimulator but not so potent then amph. Some people ask about this synthesis.
G.PattonSorry, i understood from your text that it was a prodrug that metabolized into amphetamine and theophylline?
Fenethylline is metabolized by the body to form two drugs amphetamine (24.5% of oral dose) and theophylline (13.7% of oral dose), both of which are active stimulants themselves.

But theophylline is not known for any relevant psychoactive effects. It's an excellent bronchodilator in some cases, but not much else. So the net result would be a weak dose of amphetamine and a little easier breathing, although oral theophylline has only minor short-term effects.
 
Last edited:

cyb3r0

Member
Joined
Nov 5, 2021
Messages
104
Reaction score
5
Points
18
I'm not an expert in chemistry just a hobbyist and I want to know the following ratios how much are they equivalent in grams

Theophylline 10 mmol
Sodium hydroxide 10–20 mmol
aliquat-336 0.6 mmol
1,2-dichloroethane 10–20 ml
The reaction mixture is stirred under reflux for 4 hours, filtered while hot and the precipitate dissolved in distilled water and the solution neutralized to pH 7 to give the unreacted theophylline and the synthesized symmetric 1,2-bis(7-theophyllinyl)ethane.
G.PattonAnd the other point here, do you leave it here at a certain temperature?
 

MadHatter

Well-known member
Joined
Dec 4, 2021
Messages
442
Solutions
1
Reaction score
301
Points
63
I'm not an expert in chemistry just a hobbyist and I want to know the following ratios how much are they equivalent in grams

Theophylline 10 mmol
Sodium hydroxide 10–20 mmol
aliquat-336 0.6 mmol
1,2-dichloroethane 10–20 ml

And the other point here, do you leave it here at a certain temperature?
cyb3r0A hobbyist should know how to google stuff. Otherwise it's impossible to be a hobbyist. Learn to google.
 

ACAB

Active member
Joined
Mar 27, 2022
Messages
261
Reaction score
161
Points
43
I'm not an expert in chemistry just a hobbyist and I want to know the following ratios how much are they equivalent in grams
cyb3r0Are the batteries of your calculator also empty? Or do you not know how to convert moles into g?
It's actually quite simple, every substance has a molar mass, you have to search for it, the unit is given in g/mol. Since mmol is given here, you only have to divide it by 1000, the rest is a walk in the park.
 
Top