tert-Butanol → [3-(2-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)phenyl]-carbamic acid, 1,1-dimethylethyl ester

Participants

Reaction Conditions

Reaction Steps

Triethylamine (5.23 mL, 37.5 mmol) is added to a stirred suspension of 3-(2-methyl-1H-imidazol-1-yl)-5-(trifluoromethyl)-benzoic acid (Example 91 b; 6.8 g, 25 mmol) in t-butanol (200 mL). Diphenylphosphorylazide (7.6 g, 27.5 mmol) is added to the resulting solution and the mixture is heated 80° C. for 16 h. The solvent is evaporated off under reduced pressure and the residue is treated with water (100 mL) and extracted with ethyl acetate (2×100 mL). The combined extracts are washed with brine (100 mL), dried (Na2SO4) and the solvent is evaporated off under reduced pressure to give the crude product which is purified by column chromatography (silica gel, eluent 2% ethanol in ethyl acetate) and recrystallised from ether-hexane to afford the title compound as a colourless crystalline solid, m.p. 203–208° C.

Provenance & Evidence