Ammonia → 1-methyl-5-phenyl-7-nitro-2,3-dihydro-1H-1,4-benzodiazepine

関与物質

反応条件

反応手順

To a solution of 30 ml of 1.07 M diborane in tetrahydrofuran was added with stirring 1.48 g of 1-methyl-5-phenyl-7-nitro-1,3-dihydro-2H-1,4-benzodiazepin-2-one at -13° to -8° C, and the mixture was further stirred at -8° C for 1 hour and 45 minutes. The reaction mixture was poured into ice-water, and 20 ml of concentrated hydrochloric acid was added. The mixture was refluxed for one hour. After cooling, the resultant solution was neutralized with 28%-aqueous ammonia, and extracted with chloroform. The chloroform extracts were washed with water and dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. The residue was dissolved in a 20%-solution of hydrochloric acid in ethyl alcohol, and refluxed for 10 minutes. The alcohol was removed by distillation under reduced pressure, and the residue was distributed between water and chloroform. The chloroform layer was separated, washed with water, and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure to obtain 1.34 g of 1-methyl-5-phenyl-7-nitro-2,3-dihydro-1H-1,4-benzodiazepine, which was recrystallized from isopropyl alcohol to yield yellow flakes melting at 186° to 187° C.

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