反应详情

4 g (0.011 M) of (S)-7-amino-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one are dissolved in 35 ml of ice-cold concentrated hydrochloric acid at -10° C. and chlorine gas is conducted in at -10° C. for 1 hour. The mixture is concentrated at 0°-5° C. using a high vacuum cooling trap and a soda lime tower under a high vacuum (1-2 mmHg). The residue is made alkaline with a mixture of ice and 10% sodium bicarbonate solution. The mixture is extracted with methylene chloride and the extract is dried over sodium sulphate, filtered and concentrated. The remaining oil is purified on a 300 g silica gel column using methylene chloride and then methylene chloride/ethyl acetate (20:1) as the eluting agent. This operation is repeated once on a 120 g silica gel column using methylene chloride and then methylene chloride/ethyl acetate (20:1) as the eluting agent. After crystallisation from ethyl acetate/ether, there is obtained (S)-7-amino-6-chloro-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one which melts at 222°-226° C.; [α]25D =+92° (in methylene chloride; 0.5%).

1. concentrationThe mixture is concentrated at 0°-5° C.
2. temperaturecooling trap
3. additionwith a mixture of ice and 10% sodium bicarbonate solution
4. extractionThe mixture is extracted with methylene chloride
5. dry with materialthe extract is dried over sodium sulphate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe remaining oil is purified on a 300 g silica gel column
9. customAfter crystallisation from ethyl acetate/ether