Synthesis of n-acyl- and n-aroylamino-1,2,3,6-tetrahydro 4-substituted pyridines

ABSTRACT

Reaction of N-amino-4-substituted pyridinium iodide I with the acid chlorides II afforded the ylides III in high yields. Their reduction with sodium borohydride in absolute ethanol at ice-bath temperature was found to be more favorable than in 95% ethanol to give higher yields of the title N-carbonylamino-1,2,3,6-tetrahydropyridines IV. The chemical constitution of the products was proved by spectral as well as elemental analyses