Triethylamine → 4-(2-Azetidin-1-yl-ethyl)-2-(4-bromo-phenyl)-5-methyl-oxazole

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Reaction Steps

Add methanesulfonyl chloride (0.745 g, 6.50 mmol) to a cool (0° C.) solution of 2-[2-(4-bromo-phenyl)-5-methyl-oxazol-4-yl]-ethanol (1.4 g, 5.0 mmol) and triethylamine (1.26 g, 12.5 mmol) in dichloromethane (20 mL). Warm to room temperature and stir for 1 hour. Remove solvents, transfer crude of methanesulfonic acid 2-[2-(4-bromo-phenyl)-5-methyl-oxazol-4-yl]-ethyl ester residue to a sealed tube, add tetrahydrofuran (30 mL), azetidine (2.0 g, 35.5 mmol), and heat at 60° C. overnight. Wash the crude organic material with 1N HCl. Separate layers and add 5N NaOH to the aqueous layer until it is basic. Extract the aqueous layer with diethyl ether (2×50 mL), dry the organic extracts over Na2SO4, filter, and concentrate. Purify on silica gel eluting with 10% ammoniated methanol in dichloromethane to give 4-(2-azetidin-1-yl-ethyl)-2-(4-bromo-phenyl)-5-methyl-oxazole (1.22 g, 72%): mass spectrum (m/e): 323 (M+1).

Provenance & Evidence