Toluene synthesis via Freidel-Craft's reaction

[G.Patton]

Introduction.​

I want to represent to your attention toluene synthesis method via Freidel-Craft's reaction. This method quite difficult and takes some chemical experience because there are manipulations with aggressive gases, fractional distillation and hazard substances. If you have option to buy toluene (methylbenzene) in chem shop, it would be better than suffer and provide this experiment. In other cases, use this method and be careful, use all safety equipment such as chemical glass, gloves, chemical coat and respiratory mask. Carry on experiments under pull out probe or under exhaust hood in good ventilated premises.

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Appearance: colorless liquid with a sweet, pungent, benzene-like odor;
Boiling Point: 110.6 °C/760 mm Hg;
Melting Point: -95 °C;
Molecular Weight: 92.141 g/mol;
Density: 0.86694 g/ml (20 °C).

Equipment and glassware:​

• 2 L x3 Two-neck round bottom flask;
• 0.5 L Drip funnel;
• x2 Heating mantle;
• x2 Calcium chloride tube;
• Glass tubes;
• Glass tube connector to flask throats;
• Flush flask;
• x2 Reflux condenser;
• Water-jet aspirator;
• Distillation apparatus with vigreux column;
• Retort stand and clamp for securing apparatus;
• Laboratory scale (1 — 200 g is suitable);
• 100 ml x2 and 200 ml x2 Erlenmeyer flasks with cap;
• 1 L Measuring cylinder;
• 200 ml x2; 100 ml x2 Beakers;
• Conventional funnel.

Reagents:​

• 300 ml Sulfuric acid conc. (H2SO4);
• 200 g Sodium chloride (NaCl);
• 500 ml Methanol (MeOH);
• 30 g Anhydrous zinc chloride (ZnCl2);
• 92 g Anhydrous aluminum chloride (AlCl3);
• 500 ml Benzene.

Procedure:​

1. Firstly, we are assembling the installation for toluene synthesis. First step is assembling the device for hydrochloric acid gas synthesis. A two-neck round bottom flask connected with a drip funnel with sulfuric acid (H2SO4) (control the amount of gaseous hydrogen chloride). Place sodium chloride (NaCl) on the bottom of the flask and place this flask on a heating mantle. We connect the outlet from the flask through a calcium chloride tube and through a glass tube we introduce it to the bottom of the second two-necked round bottom flask.

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2. Place the second flask in the heating mantle and pour methanol (CH3OH) (dried with magnesium or copper sulfate) into the flask. Add some anhydrous zinc chloride (ZnCl2). We connect a reflux condenser to the second neck of this flask and connect its outlet with a flush flask filled with concentrated sulfuric acid.

Spoiler: The flush flask

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3. Connect the outlet from the wash bottle to a calcium chloride tube, and then connect it to a glass tube touching the bottom of the third two-necked flask.

4. Pour 500 ml of benzene into the third flask, add 92 g of anhydrous aluminum chloride (AlCl3) and close the throat with a reflux condenser, the outlet of which is connected to a water-jet pump.

5. We turn on the apparatus by turning on the heating of benzene and methanol. As soon as the methanol starts to boil, open the drip funnel with sulfuric acid and start generating hydrogen chloride gas. Hydrogen chloride dried through calcium chloride tube, getting into boiling methanol in the presence of ZnCl2 catalyst forms monochloromethane gas (CH3Cl). Dried monochloromethane gas enters the flask with benzene and forms toluene by the Friedel-Crafts alkylation mechanism in the presence of AlCl3 catalyst.​

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6. The reaction must be controlled in time 6-8 h, since the yield of products from a certain moment begins to sharply shift towards xylenes (dimethylbenzenes).

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7. After reaction termination, the mixture of benzene, toluene and xylenes must be distilled with a vigreux column. The system is rather complex - polyazeotropic, which makes it quite difficult to obtain pure substances by multiple distillations with high vigreux column.

Spoiler: Fractional distillation with vigreux column

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Boiling points of pure substances:​

Benzene Bp = 80.1 °C;
Toluene Bp = 111 °C;
Ortho-xylene Bp = 144 °C;
Para-xylene Bp = 138 °C;
Meta-xylene Bp = 139 °C.

Download Video

Toluene synthesis

• G.Patton
• May 27, 2022
• toluene synthesis

http://bbzzzsvqcrqtki6umym6itiixfhni37ybtt7mkbjyxn2pgllzxf2qgyd.onion/threads/toluene-synthesis-v...

 

[G.Patton]

In what (drug proceeding) reactions can you use Toluene?

ArsoleDickiteYou can use it to producing benzoic acid or benzaldehyde and use them in following syntheses of mph or meth.

 

[MadHatter]

Or you could produce methaquolone (Mandrax, Quaaludes) through nitration of the toluene, isolation of o-nitrotoluene, then synth of o-toluidine, and subsequent reaction with anthranilic acid and GAA. I will post a synth description of this as soon as I have the time.

 

[T0lek511]

In czech republic is toulene in hobby market but benzene is strictly restricted chemical

 

[Jeff_Benzoz]

Toulene was first extracted from oil from pine tree- am I correct?
does anyone know how such a method is done and or right direction towards it?

 

[middlemaneu]

O-toulidine became a controlled chemical? In several EU countries can be still obtained in bulk for a dirty cheap price. But I suppose if it's ordered directly from the chemist who will work on whatever, just the idea that it could have been monitored and the name/address noted down, would cause some random paranoia. I heard several chemists from UK saying the knocks are not so rare and getting whatever chemical in bulk is already something to be concerned about.
LE got really nothing better to do -_-