Functional derivatives of thiophene

The nitration of 3-ethoxycarbonyl-4-hydroxy-2-methyl- and 4-chloro-3-ethoxycarbonyl-2-methylthiophenes has given the corresponding 5-nitro derivatives of thiophene. The 4-chloro-3-ethoxycarbonyl-2-methylthiophene was synthesized by the decarboxylation of 3-chloro-4-ethoxycarbonyl-5-methylthiophene-2-carboxylic acid, which is formed by the oxidation of 3-chloro-4-ethoxycarbonyl-5-methylthiophene-2-carbaldehyde.For Communication IV, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1024–1025, August, 1973.     

Synthesis of derivatives of 2-aminothiophene and of thienoxazine

2-Amino-3-ethoxycarbonylthiophenes are synthesized by condensing alkylidenecyanoacetic esters with sulfur, and converted to a series of 2-aminothiophene derivatives. 4-Oxothienooxazine derivatives are synthesized by reaction of 2-acetylaminothiophene-3-carboxylic acid with acetic anhydride.     

Alkyl- and arylamination of 3-hydroxy-4-carbethoxy-5-methylthiophene

N-Alkylaminothiophene derivatives were obtained by the reaction of 3-hydroxy-4-carbethoxy-5-methylthiophene with alkylammonium acetates, while N-arylaminothiophene derivatives were obtained by the reaction of the same thiophene derivative with aromatic amines in the presence of catalytic amounts of iodine.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 12, pp. 1602–1604, December, 1970.