4-Methoxybenzenethiol

Synthesis

To a 1000 mL three-necked flask, add 0.25 mol of aromatic compound anisole and 700 mL of 1,2-dichloroethane. Start mechanical stirring and slowly add chlorosulfonic acid (the amount added is 3 times the theoretical amount). During the addition, control the substrate temperature at approximately 50 °C using a water bath. After the addition is complete, raise the temperature to 80 °C and maintain the temperature for 1 h. After the reaction is complete, remove the solvent under reduced pressure. The obtained solid is recrystallized from n-heptane to obtain pure aromatic sulfonyl chloride. The average yield of the intermediate product is 85%.

Take 0.1 mol of the prepared aromatic sulfonyl chloride and add it to a 500 mL three-necked flask. Add 200 mL of n-heptane and start mechanical stirring. Control the substrate temperature at 85 °C in a water bath. Add triphenylphosphine in batches (the amount added is 3 times the amount of the sulfonyl chloride group). After the addition is complete, continue the reaction at 85 °C for 1 h. Then cool down to 50 °C, add 100 mL of water dropwise to the system and continue the reaction for 10 min. After the reaction was complete, the system separated into layers. The oil phase was extracted with 10% sodium hydroxide solution (50 mL × 3). The organic layer was removed by vacuum distillation to remove n-heptane, yielding the byproduct triphenylphosphine oxide, which was stored for later use. The alkaline layer was acidified with 37% hydrochloric acid to pH 1–3, and then extracted with dichloromethane (50 mL × 3). The organic layer was dried with anhydrous sodium sulfate, and the dichloromethane was removed by vacuum distillation, yielding the crude aromatic thiophenol.

Chemical Properties

Uses

Synthesis Reference(s)