B. V. Golomolzin

Covalent hydration in the tetrazolo [1,5-c]quinazoline series (structure of the products of hydration of 5-methyl(phenyl)-9-bromotetrazolo[1,5-c]-quinazolines)

Abstract1(2)-Methyl-5-(2-acylamino-5-bromophenyl)tetrazoles (VIa,b), the structures of which were proved by alternative synthesis, were obtained by the action of diazomethane on the products of covalent hydration of 5-methyl(phenyl)-9-bromotetrazolo[1,5-c]quinazolines. A comparison of the IR and UV spectra of the hydration products and VIa and VIb confirms that the former have the 5-(2-acylamino-5-bromophenyl)tetrazole structure (IIa,b) in the crystalline state and in solution.

Ring-chain tautomeric transformations of the product of diazotization of 5-(2′-aminophenyl)tetrazole

It was established on the basis of IR spectral data that the products of the reaction of 5-(2′-aminophenyl)tetrazole and 4-hydrazinobenzo-1,2,3-triazine with amyl nitrite have the 5-(2′-diazoniaphenyl)tetrazolestructure in the crystalline state. A study of the UV spectra of the latter showed that in methanol solution it exists in equilibrium with the isomeric 4-azidobenzo-1,2,3-triazine.

Investigations in the benzodiazine series

Abstract5-Phenyl-9-bromotetrazolo[1, 5c]quinazoline (I) was synthesized. It was shown that I is covalently hydrated at the N(6)=C(5) bond. The structure of the covalent hydrate (V) was confirmed by cleavage to 5-(2′-amino-5′-bromophenyl) tetrazole. The probable mechanisms of the covalent hydration and cleavage are examined. V was converted to the 5-methyl derivative (VII).

Investigations on benzodiazines

The luminescence properties of 6-methoxy-2-phenyl-4-piperidino-quinazoline and 6-methoxy-4-morpholino-2-phenylquinazoline, synthesized for the first time, have been studied.

Studies on benzodiazines: XV. Synthesis and properties of some derivatives of quinazoline and of tetrazolo[1,5-c]quinazoline with substituents in the benzene nucleus

Derivatives of 5-phenyltetrazolo[1,5-c]quinazoline with substituants in the benzene nucleus — 7-methyl-5-phenyltetrazolo[1,5-c]-quinazoline and 9-methyl-5-phenyltetrazolo-[1,5-c]quinazoline — have been obtained for the first time. The oxidation of the 9-methyl derivative gave the corresponding carboxylic acid which, in contrast to the 5-phenyltetrazolo[1,5-c]quinazoline unsubstituted in the benzene nucleus, is covalently hydrated.