Ethyl isocyanate → Urea, N-(6-chloro-5-(2-fluorophenyl)-2,3-dihydro-1-methyl-2-oxo-1H-1,4-benzodiazepin-7-yl)-N(sup 1)-ethyl-
Reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]([CH3:12])[C:10](=[O:13])[CH2:9][N:8]=[C:7]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=3[F:20])[C:6]=2[C:21]=1[Cl:22].[CH2:23]([N:25]=[C:26]=[O:27])[CH3:24]>>[Cl:22][C:21]1[C:6]2[C:7]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][C:15]=3[F:20])=[N:8][CH2:9][C:10](=[O:13])[N:11]([CH3:12])[C:5]=2[CH:4]=[CH:3][C:2]=1[NH:1][C:26]([NH:25][CH2:23][CH3:24])=[O:27]Participants
3
Procedure
5 g (0.016 M) of 7-amino-6-chloro-5-(o-fluorophenyl)-1,3-dihydro-1-methyl-2H-1,4-benzodiazepin-2-one are heated at reflux with 15 ml of ethylisocyanate under nitrogen for 7 hours. The mixture is poured on to methanol/ice-water and extracted with methylene chloride. The organic phase is separated, dried with sodium sulphate, filtered and concentrated. The residue is purified on a 300 g silica gel column using ethyl acetate as the eluting agent and crystallised from ethyl acetate/ether. There is obtained 1-[6-chloro-5-(o-fluorophenyl)-2,3-dihydro-1-methyl-2-oxo-1H-1,4-benzodiazepin-7-yl]-3-ethylurea which melts at 155°-160° C. with decomposition.