tert-Butanol → HCID 19100786, compound

Participants

Reaction Steps

A mixture of 2-t-butoxycarbonylamino-4-isopropylthiophene-3-carboxylic acid (4.0 g, 14.0 mmol) in 2-methyl-2-propanol (125 ml), triethylamine (1.8 g, 18.2 mmol) and diphenylphosphoryl azide (4.25 g, 15.4 mmol) was heated at reflux for 64 h. 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 1.4 g (28%) of di-t-butyl 4-isopropylthiophene-2,3-dicarbamate. 1H-NMR (CDCl3, δ): 1.15 (d, 6H), 1.5 (s, 18H), 2.75 (m, 1H), 6.0 (br.s, 1H), 6.5 (s, 1H), 7.65 (br.s, 1H).

Provenance & Evidence