Hydrochloric Acid → 6-((S)-2-methyl-pyrrolidine-1-carbonyl)-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-((S)-2-methyl-pyrrolidine-1-carbonyl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid ethyl ester (Comp. No. 6c) (762 mg, 2.49 mmol) in methanol (10 ml) was added water (4 ml) and 2 N aqueous potassium hydroxide (6 ml, 12 mmol). The mixture was stirred for 3 h at 80° C., then cooled down to 25° C. and 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 595 mg (86%) 6-((S)-2-methyl-pyrrolidine-1-carbonyl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid as a white solid. LC/MS (method 2): Rt=0.98 min; m/z=279.06 (M+H+).

Provenance & Evidence