(S)-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one → (S)-7-amino-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one

Participants

Reaction Conditions

Reaction Steps

1 g of (S)-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one is introduced portionwise into 10 ml of concentrated hydrochloric acid while cooling with ice at 0° C. The solution obtained is treated slowly at 0° C. with 2 g of stannous chloride, stirred for 30 minutes while cooling with ice, poured into ice/sodium bicarbonate solution and extracted several times with methylene chloride. The organic phase is dried over sodium sulphate, filtered and concentrated. After crystallisation from ether, there is obtained (S)-7-amino-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one which crystallises with 1 mol of ether; melting point 100°-110° C. (with decomposition); [α]25D =+77.1° (in methylene chloride; 1%).

Provenance & Evidence