Effect of the reaction conditions on the character of the products of acetylation of 2-methylmercapto-, 2-methoxy-, and 2-dimethylaminothiophene

Acetylation of 2-methylmercaptothiophene by the action of acetyl chloride in methylene chloride at –70°C in the presence of excess AlCl₃ gives a mixture of 5-methylmercapto-2-acetylthiophene, 5-methylmercapto-2,4-diacetylthiophene, and a small amount of 3-acetyl-substituted derivative. The acetylation of 2-methoxythiophene gives similar results. 5-Dimethylamino-2-acetylthiophene was obtained from 2-dimethylaminothiophene under similar conditions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 486–489, April, 1973.