Betylates. 1. Synthesis and reactions of an isolable [0]betylate, N,N-dimethyl-N-(phenoxysulfonyl)methanaminium fluorosulfate

Abstract

Phenyl [0]betylate fluorosulfate (2), the first example of a "[0]betylate" (trialkylammoniosulfate ester), has been prepared by methylation of phenyl N,N-dimethylsulfamate with methyl fluorosulfate. Nucleophiles react with 2 either by attack on the sulfur or methyl carbon atoms, but with no sign of any products derived from benzyne or the phenyl cation. A synthesis of enol N,N-dimethylsulfamates has been devised using a reagent, [Formula: see text], prepared from tetramethylsulfamide and methyl fluorosulfate, but no satisfactory method was found for converting the sulfamic ester to the [0]betylate. Evidence is presented that phenyl chlorosulfate reacts with trimethylamine to give the phenyl [0]betylate which then undergoes further reaction.