Hydrochloric Acid → 6-[(R)-1-(4-fluoro-phenyl)-ethylcarbamoyl]-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid

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Reaction Conditions

Reaction Steps

To a solution of 6-[(R)-1-(4-fluoro-phenyl)-ethylcarbamoyl]-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid ethyl ester (9.0 g, 25 mmol) in methanol (38 ml) was added 2 N aqueous sodium hydroxide (38 ml, 76 mmol). The mixture was stirred for 1 h at 60° C., then cooled down to 25° C. acidified with excess 10 M aqueous hydrochloric acid. After extraction (3 times with dichloromethane), the combined organic layers were dried over sodium sulfate and the solvents evaporated to give 7.2 g (85%) 6-[(R)-1-(4-fluoro-phenyl)-ethylcarbamoyl]-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid as a white solid. LC/MS (method 4): Rt=1.11 min; m/z=333.06 (M+H+).

Provenance & Evidence