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.