METHYLATION OF 5-PHENYL-1,4-BENZODIAZEPIN-2-ONE DERIVATIVES WITH N,N-DIMETHYLFORMAMIDE-DIMETHYL ACETAL

A novel method for N-methylation of the cyclic amide in the 1,4-benzod iazepine ring system is presented. Methods traditionally used involve treatment of the 1,4-benzodiazepinone anion with an alkyl halide. It h as been demonstrated that these derivatives can be methylated on the a mide nitrogen atom by use of dimethylformamide dimethyl acetal which a cts as both reagent and solvent for the reaction.