Lithium Hydroxide → 4-(4-{[(1,1-Dimethylethyl)oxy]carbonyl}-2,3,4,5-tetrahydro-1,4-benzoxazepin-7-yl)benzoic acid

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Reaction Conditions

Reaction Steps

To a slurry of 1,1-dimethylethyl 7-{4-[(methyloxy)carbonyl]phenyl}-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (9.8 g, 26 mmol) in tetrahydrofuran (40 mL) was added a solution of lithium hydroxide (3.1 g, 130 mmol) in water (15 mL). The resulting mixture was heated at 60° C. for 18 h then partitioned between ethyl acetate (100 mL) and 1M hydrochloric acid (50 mL). The organic layer was washed with brine (50 mL), dried over anhydrous magnesium sulfate, filtered and concentrated. Purification by silica gel column chromatography (5% methanol in dichloromethane) provided 4-(4-{[(1,1-dimethylethyl)oxy]carbonyl}-2,3,4,5-tetrahydro-1,4-benzoxazepin-7-yl)benzoic acid (8.1 g, 85% yield). MS (EI) for C21H23NO5: 370 (MH+).

Provenance & Evidence