Ammonia → Medazepam

Beteiligte Stoffe

Reaktionsschritte

To a suspension of 2.28 g of sodium borohydride in 35ml of tetrahydrofuran was added dropwise with stirring a solution of 13.0 g of boron trifluoride etherate in 10ml of tetrahydrofuran below 10° C, and the mixture was stirred at room temperature for 45 minutes. To the mixture was added dropwise solution of 1.43 g of 1-methyl-5-phenyl-7-chloro-1,3-dihydro-2H-1,4-benzodiazepin-2-one in 10 ml of tetrahydrofuran at -15° to -12.5° C over a period of 5 minutes, and then the mixture was stirred at =15° C for 22 hours. The reaction mixture was poured into 100 ml of ice-water, and then 20 ml of concentrated hydrochloric acid was added. The mixture was refluxed for 30 minutes, then cooled, and neutralized with concentrated ammonia. The tetrahydrofuran layer was separated, and the aqueous layer was extracted with ether. The combined organic layer was washed with water and dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain 1.4 g of 1-methyl-5-phenyl-7-chloro-2,3-dihydro-1H-1,4-benzodiazepine.

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