Triethylamine → (R)-1-(2-chlorophenyl)ethyl (5-(4-bromophenyl)-3-methylisoxazol-4-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

5-(4-Bromo-phenyl)-3-methyl-isoxazole-4-carboxylic acid (10 g, 35 mmol), (R)-1-(2-chloro-phenyl)-ethanol (6.6 g, 42 mmol), triethylamine (10 mL, 70 mmol), and diphenylphosphoryl azide (11.5 g, 42 mmol) were combined in toluene (100 mL) and stirred at 90° C. for 1 hour. The mixture was concentrated, and the residue was purified by silica gel chromatography (0-30% EtOAc in hexanes). The isolated product was recrystallized in 5:1 hexanes:acetone to give the title compound in >99% e.e (by chiral HPLC. Chiracel OD 98.4% hexanes/1.6% Ethanol. Major isomer 27.9 min minor isomer 32.7 min).

Provenance & Evidence