3-Methyl Flunitrazepam → rac-7-amino-5(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one

Participants

Reaction Steps

85 g (0.26 M) of rac-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one are dissolved in 700 ml of concentrated hydrochloric acid and treated slowly with 180 g of stannous chloride. After about 15 minutes, the mixture is cooled with ice and then concentrated on a rotary evaporator. The residue is dissolved in ice-water, slowly made alkaline with 200 g of sodium carbonate in 1 liter of water and extracted several times with methylene chloride. The organic solution is dried over sodium sulphate, filtered and concentrated. The residue is crystallised from ethyl acetate and there is obtained rac-7-amino-5(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one which melts at 178°-180° C.

Provenance & Evidence