ON THE SYNTHESIS OF NITRILIUM SALTS FROM NITRILES AND CHLOROFORMATES

Nitriles react with methyl or ethyl chloroformate (2a,b) and antimony( V) chloride to give high yields of N-methyl-, or N-ethyl-nitrilium hex achloroantimonates 3,4. With butyl chloroformate (2c) N-(1-methylpropy l)nitrilium salts 6 are obtained. These products arise from a 2-butyl cation, which is formed prior to alkylation of the nitrile. Isobutyl c hloroformate (2d), (2-tert-butylcyclohexyl) chloroformate (2e), menthy l chloroformate (2f), 2,2-dimethylpropyl chloroformate (2g), and 3-met hylbutyl chloroformate (2h) react with nitriles to give N-tert-alkylni trilium salts, 11,13,15,19, which were characterized by hydrolysis to amides. With phenyl chloroformate (2i) benzonitriles react in a 1 : 2 ratio to furnish 2-phenoxy-1,3,5-oxadiazinium salts 21.