4-Aminothiophenol → 4-(6-Chloro-2-quinoxalylthio)-aniline

Participants

Reaction Steps

5.7 g (0.045 mol) of p-aminothiophenol together with 3 g (0.045 mol) of 86% potassium hydroxide and 2 ml of water in 80 ml of dimethylsulfoxide was heated under stirring at 80°-90° C. for 5 hours to make the potassium p-aminothiophenolate. The water generated was removed off by azeotropic distillation under reduced pressure. To this solution which was allowed to be cooled to room temperature was added a solution of 9 g (0.045 mol) of 2,6-dichloroquinoxaline dissolved in 100 ml of dimethylsulfoxide. The mixture was subjected to the reaction, while stirring, at 80°-90° C. for 8 hours. After the reaction mixture was cooled to the room temperature, it was poured into a great deal of water and stirred. The precipitating solid was filtered off, washed with 5% aqueous solution of sodium hydroxide and then washed with water, followed by drying. The crude crystals thus obtained were recrystallized from a mixed solution of ethanol-benzene to produce 6.7 g (yield 52%) of the intended compound (Compound No. 10) as light-yellow crystals, m.p. 144°-147° C.

Provenance & Evidence