Hydrochloric Acid → tert-Butyl [(4-cyano-7-fluoro-5-methyl-6-phenyl-1,3-benzoxazole-2-carbonyl)methylamino]acetate

Participants

Reaction Steps

Under nitrogen atmosphere, trimethylaluminium (1.03 M n-hexane solution, 4.50 ml, 4.63 mmol) was dropwise added at room temperature to a dichloromethane (6 ml) solution of N-methylglycine tert-butyl ester hydrochloride (840 mg, 4.63 mmol), followed by stirring for 25 hours. Subsequently, a dichloromethane (4 ml) solution of ethyl 4-cyano-7-fluoro-5-methyl-6-phenyl-1,3-benzoxazole-2-carboxylate (I-111) (500 mg, 1.54 mmol) was dropwise added, followed by stirring for 23 hours. After the reaction, aqueous 1 N hydrochloric acid solution was added to the reaction liquid with cooling with ice, followed by stirring at room temperature, and the reaction liquid was extracted with chloroform. Next, the obtained organic layers were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was suspended and washed in diethyl ether to obtain the entitled compound (569 mg, 87%) as a white solid.

Provenance & Evidence