3-Thiophenecarboxylic acid, tetrahydro-4-oxo-, methyl ester → HCID 12953041, compound

Participants

Reaction Steps

Ethyl 6-aminonicotinate (2.5 g., 0.015 mol), methyl 4-oxotetrahydrothiophene-3-carboxylate (6.2 g., 0.039 mol) and p-toluenesulfonic acid monohydrate (0.25 g) are thoroughly mixed and heated at 155°-160° C. under nitrogen for 90 minutes. The distillate is collected in a Dean-Stark trap. The residue is cooled, triturated with boiling ethanol and filtered. Recrystallization from methanol gives yellow crystals (1.2 g.), mp 183°-185° C.

Provenance & Evidence