1-methyl-1,4-benzodiazepin-2-ones prepn - by n-methylation with methyl benzenesulphonate

摘要

Cpds. of formula (I): (where R3 is halogen or NO2) are prepd. by reacting cpds. of formula (II) with methyl benzenesulphonate in a molar ratio of 0.5:2 in the presence of methanol and NaOH at 40-45 degrees C, the product obtd. being purified by dissolving in butyl acetate and washing with extraction benzene or by selective temp.-dependent crystallisation from IPA.