Hydrogen Bromide → 1,3-dihydro-5-cyclohexyl-3(R,S)-amino-2H-1,4-benzodiazepin-2-thione

Participants

Reaction Conditions

Reaction Steps

1,3-Dihydro-5-cyclohexyl-3(R,S)-[(benzyloxycarbonyl)-amino]-2H-1,4-benzodiazepin-2-thione (787 mg, 1.93 mmole) was dissolved in 40 ml of a 1:1 mixture of methylene chloride and acetic acid. The resulting solution was cooled to 0° C. and a continuous stream of hydrogen bromide gas was passed into the stirred solution for 10 minutes. The reaction vessel was capped and the reaction mixture was allowed to warm to ambient temperature over 5 hours. All volatiles were removed under reduced pressure and the yellow residual solid was azeotropically dried with toluene. This material was partitioned between 180 ml of ethyl acetate and 7.3 ml of 10% sodium carbonate solution. The resulting suspension was stirred for 5 minutes and then filtered. The filter cake was washed with ethyl acetate, dried in vacuo over phosporus pentoxide (40° C.), and triturated with ethyl acetate-hexane (1:1) to give 492 mg of the title compound (93% yield).

Provenance & Evidence