Methyl 5-methyl-4-nitrothiophene-2-carboxylate → Methyl 4-amino-5-methylthiophene-2-carboxylate

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Reaction Steps

5-Methyl-4-nitro-thiophene-2-carboxylic acid methyl ester [15.09 g., 75.0 mM, Intermediate (23)] is dissolved in ethyl acetate (200 mL) to which 10% palladium on charcoal (1.03 g) is added and the mixture is shaken under 50 psi of hydrogen. The catalyst is removed by filtration and the solvent is removed leaving 4-amino-5-methyl-thiophene-2-carboxylic acid methyl ester [12.82 g., 99.8%, Intermediate (24)] as a yellow solid; MS 171.9 (100%, M+1).

Provenance & Evidence