Thiophene-3-carboxylic acid → HCID 12796524, compound

Participants

Reaction Steps

A solution of 3-thiophenecarboxylic acid (10 g, 78 mmol) in 250 mL of THF at 0° C. under N2 was added 2.0 M LDA (2.2 eq., 86 mL) dropwise. After 10 min at 0° C., p-anisaldehyde (10.6 mL, 1.12 eq.) was added and the mixture was slowly warmed to room temperature overnight. The reaction was stirred for ˜14 h, after which 100 mL of ice-water was added, and the solvent was evaporated. The aqueous solution was washed with EtOAc (2×40 mL), and then added KMnO4 (2 eq., 12.4 g) dropwise at 0° C. The ice-bath was removed and the reaction was heated to 60° C. for 3 h. The solid was collected and washed with hot water. The aqueous layer was acidified to pH ˜3, extracted with EtOAc (3×50 mL). The combined EtOAc was dried and evaporated. The crude solid was dissolved in 50 mL of EtOH, and NH2NH2.H2O (1.5 eq., 1.5 mL) was added dropwise. The reaction was heated to 80° C. for 3 h, and the resulting solid was collected and washed with EtOH to give 3.6 g (36%): MS m/z 259 (M+H).

Provenance & Evidence