Methylamine → Urea, N-(6-chloro-5-(2-fluorophenyl)-2,3-dihydro-1-methyl-2-oxo-1H-1,4-benzodiazepin-7-yl)-N(sup 1)-methyl-

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Reaction Steps

Excess gaseous methylamine is conducted into a dichloroethane solution of [6-chloro-5-(o-fluorophenyl)-2,3-dihydro-1-methyl-2-oxo-1H-1,4-benzodiazepin-7-yl]isocyanate, obtained in analogy to the procedure described in paragraph (a) of Example 1 from 10 g (0.031 M) of 7-amino-6-chloro-5-(o-fluorophenyl)-1,3-dihydro-1-methyl-2H-1,4-benzodiazepin-2-one, and the mixture is concentrated. The residue is dissolved in methylene chloride/water and extracted with methylene chloride. The organic phase is separated, dried with sodium sulphate, filtered and concentrated. After purification on a 500 g silica gel column using ethyl acetate as the eluting agent, the product is 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-methylurea which melts at 145°-160° C. with decomposition.

Provenance & Evidence