Studies in the benzodiazine series

It has been shown that when there is no substituent in position 5 of a tetrazolo1, 5-c]quinazoline covalent hydration at the N(₆)=C(₅) bond and cleavage of the pyrimidine ring with the formation of 5-(2-aminophenyl)-tetrazole take place more readily than in the case of the 5-methyl derivative. The 5-phenyl derivative of tetiazolo1, 5-c]quinazoline does not undergo hydration. The mechanism of the hydration of the compounds mentioned is discussed.For communication VIII, see 1].