EFFECT OF INTRAMOLECULAR HYDROGEN-BOND ON THE AZIDE-TETRAZOLE EQUILIBRIUM OF 5-(2'-HYDROXYPHENYL)TETRAZOLO[1,5-A]PYRIMIDINE, 5-(2'-HYDROXYPHENYL)TETRAZOLO[1,5-C]PYRIMIDINE, 5-(2'-HYDROXYPHENYL)TETRAZOLO[1,5-C]QUINAZOLINE, AND 7-(2'-HYDROXYPHENYL)TETRAZOLO[1,5-C]PYRIMIDINE

The intramolecular hydrogen bond between the phenolic hydroxyl and the pyrimidine nitrogen atom in the title compounds exerts a destabilizin g effect on the tetrazole ring and shifts the azide-tetrazole equilibr ium toward the azide farm, especially in the case of tetrazolo[c]pyrim idine and -[c]quinazoline. It has been found that the introduction of a methoxy group into the ortho-position of the phenyl fragment stabili zes the tetrazole tautomer more efficiently than introduction of this group into the para-position.