Zur Methylierung von Lactamen mit Dimethylsulfat

Abstract

In contradiction to the hitherto existing opinion lactim ethers are the only methylation products of lactams with dimethylsulfate. The occurrence of N-methyllactams often observed in former work must have been the result of isomerizations under the catalytic action of undestroyed dimethylsulfate during isolation. An excess of the alkylating agent must be used to obtain acceptable conversions with lactams containing more than ten atoms in the ring. Methods for the preparation of O-methyllactimethers and N-methyllactams in high yields are described.