tert-Butanol → tert-butyl N-{4H,5H,6H-cyclopenta[b]thiophen-2-yl}carbamate

Participants

Reaction Steps

To a solution of 4H,5H,6H-cyclopenta[b]thiophene-2-carboxylic acid (1.68 g, 9.99 mmol, 1.00 equiv) in tert-butanol (25 mL) was added DPPA (4.95 g, 17.99 mmol, 1.80 equiv) and triethylamine (3.03 g, 29.94 mmol, 3.00 equiv) at room temperature under nitrogen. The resulting solution was heated to reflux overnight in an oil bath and concentrated in vacuo. The residue was diluted with 100 mL of ethyl acetate and washed with brine, dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:10) to provide 1.6 g (67%) of tert-butyl N-[4H,5H,6H-cyclopenta[b]thiophen-2-yl]carbamate as a white solid. MS (ES): m/z 240 (M+H)+.

Provenance & Evidence