tert-Butanol → HCID 19100804, compound

Participants

Reaction Steps

A mixture of 2-t-butoxycarbonylamino-4-cyclopropylthiophene-3-carboxylic acid (2.6 g, 9.1 mmol) in 2-methyl-2-propanol (100 ml), triethylamine (1.2 g, 11.9 mmol) and diphenylphosphoryl azide (2.8 g 10.1 mmol) was heated at reflux for 84h. The reaction mixture was concentrated in vacuo and the residue taken up in dichloromethane which was successively washed with a 5% citric acid solution, water and an aqueous sodium bicarbonate solution. The organic phase was dried (MgSO4) and concentrated in vacuo to give 1.7 g (52%) of di-t-butyl 4-cyclopropylthiophene-2,3-dicarbamate. 1H-NMR (CDCl3, δ) : 0.55 (m, 2H) , 0.85 (m, 2H), 1.52 (s, 9H), 1.55 (s, 9H), 1.60 (s, 1H), 6.3 (br.s, 1H), 6.35 (s, 1H), 8.15 (br.s, 1H).

Provenance & Evidence