Hydroxamic acids. V. The alkylation of O-alkylarylhydroxamic acids

Abstract

The reactions of O-alkylarylhydroxamic acids with a variety of alkylating agents, to yield mixtures of the N,O-dialkyl and 0,O'-dialkyl products, are described. Spectral data and independent synthesis allow the unambiguous assignment of structure to these isomeric products. Substituents on the aryl ring exert an electronic influence on the ratio of the two products; the extent of this influence varies with the alkylating agent. Diazomethane, triethyloxonium tetrafluoroborate and methyl fluorosulphonate give largely, but not exclusively, the 0,O'-dialkyl product. Methyl fluorosulphonate, in the presence of a base, reacts further to form an unstable salt which appears also to function as an alkylating agent.