Identification of an intact sydnonimine ring depending on the reaction substituents of mesocarb by gas chromatography/mass spectrometry

Abstract

Trifluoroacylated, trimethylsilylated and methylated mesocarb (3-(1-methyl-2-phenylethyl)-5-[[(phenylamino) carbonyl]amino]-1,2,3-oxadiazolium) were analyzed by gas chromatography/mass spectrometry (GC/MS). In trifluoroacylation, N -trifluoroacylated sydnophen (SP-NTFA), where the exocyclic nitrogen atom of the sydnonimine ring attacks N-methylbis(trifluoroacetamide), was identified by GC/MS, However, in trimethylsilylation, C -trimethylsilylated sydnophen (SP-CTMS), where the C-4 atom of the sydnonimine ring attacks N -methyl-N -trimethylsilyltrifluoroacetamide, was detected. SP-NTFA and SP-CTMS are intermediates of mesocarb in pyrolysis, and retain an intact sydnonimine ring. In methylation, a ketene form of mesocarb reacts as a nucleophile with methyl iodide to produce methylated N-nitroso-N-cyanomethylamphetamine. Thus, depending on the reaction substituents, the intermediate of mesocarb in pyrolysis was identified to be either an intact sydnonimine ring skeleton or an open-ring compound using GC/MS. Copyright (C) 1999 John Wiley & Sons, Ltd.