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-

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Reaction Steps

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.

Provenance & Evidence