Benzenethiol, 2-chloro-4-methyl- synthesis

Yield:5375-97-3 78%

Reaction Conditions:

Stage #1: 2-chloro-4-methyl-benzenaminewith hydrogenchloride;NaNO₂ in lithium hydroxide monohydrate at -10; for 1 h;
Stage #2: with potassium ethylxanthate in lithium hydroxide monohydrate at 80; for 1 h;

Steps:

3.a a) Preparation of 2-chloro-4-methylthiophenol

At a low temperature of -10°C, sodium nitrite (293 mmol) was dissolved in water (100 mL), which was then added dropwise to 2-chloro-4-methylaniline (245 mmol) in hydrochloric acid (3 mol/L, 200 mL) In the solution, after the dropwise addition was completed, the reaction was continued at -10°C for 1 hour. The reaction solution was then heated to 80°C, and an aqueous potassium ethylxanthate solution (414 mmol, dissolved in 120 mL of water) was added dropwise to the reaction solution. After reacting for 1 h, it was cooled to room temperature, and the organic layer was washed with saturated aqueous sodium bicarbonate solution and water. The organic phase was then added portionwise to a KOH solution (1220 mmol, dissolved in 52 mL of water and 280 mL of ethanol) and heated to reflux for 21 hours. The reaction solution was cooled to 0°C, diluted with ice water (500 mL), adjusted to pH 2 with hydrochloric acid, extracted with ethyl acetate, the organic phase was collected, washed with water and saturated brine, dried over anhydrous sodium sulfate, filtered and spun to dryness. Removal of solvent gave 2-chloro-4-methylthiophenol (78%).

References:

CN114890987,2022,A Location in patent:Paragraph 0104-0107