On triazoles XLIII[1]. Synthesis of 1,2,4-triazolyl isoquinolinium zwitterions

Type 8 isoquinolinium zwitter ions were synthesised by the reaction of type 1 diketones or type 2 pyrylium salts with different 5-amino-3-Q-1H-1,2,4-t riazoles. Spectroscopic and X-ray diffraction evidence was given for the zw itter ion structure of the products obtained. The position of the negative charge on the 1,2,4-tiazolium ring was proved by comparison of the cmr and uv spectra of the products obtained with the three possible N-benzyl deriva tives 14-16 prepared for this purpose.