Sodium Hydroxide → prop-2-en-1-yl 7-(3,4-diaminophenyl)-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate

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Reaction Conditions

Reaction Steps

Prop-2-en-1-yl 7-(4-amino-3-nitrophenyl)-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (4.2 g, 11.2 mmol) was taken into glacial acetic acid (25 mL) and the solution was warmed to 45° C. Tin (II) chloride (8.51 g, 44.8 mmol) was added in portions over 5 minutes and the mixture was allowed to stir at this temperature for 6 h. The mixture was then cooled to room temperature and diluted with MTBE (100 mL). 50% aqueous sodium hydroxide was then added in small portions with stirring until complete precipitation of tin salts occurred. Anhydrous sodium sulfate was then added in portions until the precipitated salts formed a fine granular solid and the mixture was filtered. The filter cake was washed with additional MTBE and the combined organic filtrate was concentrated. The residue was partitioned with ethyl acetate and saturated aqueous sodium bicarbonate. 50% aqueous sodium hydroxide was added to the biphasic mixture in portions until the aqueous pH was 9-10. The layers were then separated and the organic solution washed with brine then dried over anhydrous sodium sulfate, filtered and concentrated to provide prop-2-en-1-yl 7-(3,4-diaminophenyl)-2,3-dihydro-1,4-benzoxazepine-4(5H)-carboxylate (2.7 g, 71% yield) as a yellow solid. MS (EI) for C19H21N3O3: 340 (MH+).

Provenance & Evidence