tert-Butanol → tert-Butyl thiophen-3-ylcarbamate

Participants

Reaction Steps

3-Thiophenecarboxylic acid (31 g, 0.24 mol), Diphenylphosphoryl azide (57 mL, 0.26 mol) and triethylamine (36 mL, 0.26 mol) were combined in dry tert-butanol (450 mL) and the resulting solution was heated to reflux. After 22 h the cooled solution was concentrated in vacuo to remove solvent. The residue was taken up in diethyl ether (1.5 L) and washed with 5% aqueous citric acid, water and brine (1.5 L each), dried (Na2SO4), and concentrated in vacuo to give the crude product as a tacky tan solid (51 g). Recrystallization from hot ethyl acetate-hexane gave the title compound (33 g, 69%, m.p. 139-41° C.) as shiny off-white needles.

Provenance & Evidence