3-Thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl ester → Methyl 4-aminothiophene-3-carboxylate Hydrochloride

Participants

Reaction Steps

3-Oxo-4-methoxycarbonyltetrahydrothiophene (28 g) was heated under reflux for 1 hour with hydroxylamine hydrochloride (11.5 g) in methanol (80 ml). The mixture was then cooled and a first crop was filtered off and washed with dry diethyl ether to afford the title compound (18.4 g, 57.6%) m.p. 203° to 205° C. On further cooling a second crop (2.7 g, 8.5%) was obtained, m.p. 201° to 202° C. The total yield was thus 66.1%.

Provenance & Evidence