RESUMO
The reaction of active methylene reagents with sulphonylazides is one of the best known methods for preparing polyfunctional diazo compounds. However, active methylene nitriles and active methylene ketones have been shown to afford in some cases cyclic 1,2,3-triazoles. Reactions of this type have been reviewed several times in literature .In connection with our interest in the synthesis of heterocyclic derivatives from activated nitriles we have investigated the reaction of p-tosylazide with several activated nitrile derivatives. It has been found that tosylazide reacts with benzoylacetonitrile in ether in the presence of sodium hydroxide to yield a product of molecular formula C[16]H[12]N[4]O[2]S. Structure 3 was readily established for the reaction product based on its IR spectrum which revealed the absence of diazo group absorption. Treatment of compound 3 with equimolecular amount of hydrazine hydrate at 100 degree in absence of a solvent afforded a mixture of two products of mp. 125 degree and 193 degree which were separated by fractional crystallization from ethanol. The product of the mp. 125 degree was shown to be the amidrazone 4 based on its analytical data and the absence of absorption for cyano- and diazo- functions in its IR spectrum. On the other hand, the other product revealed analytical data indicating that it is only an isomer for 3; its IR spectrum revealed the presence of cyano- and diazo- functions, consequently structure 5 was suggested for this product. Similar isomerisatian of 1, 2, 3-triazoles into diazo- compounds has been observed in literature and reactions of this type have been summarized by Regitz. The isomerisatian of 3 into the diazo- derivative 5 prompted us to try isomerisatian of the 1,2,3-triazole 6, prepared by Regitz et al by the reaction of malononitrile with 1, into the diazo- derivative 7. However, the reaction afforded the amidrazone on treatment with phenylhydrazine. Compound 1 also reacted with 1,1, 3-tricyano-2- aminopropene under similar conditions to yield the 1,2,3-triazole derivative 10. Attempts to convert this compound into the diazo- derivative 11 by our procedure or other reported procedures for isomerising 1, 2, 3-triazoles into diazo-derivatives, were unsuccessful. In contrast to the observed behaviour of active methylene nitriles, the aryl-hydrazononitriles 12a-c were treated with sodium azide in DMF to yield 1,2,3,4-tetrazole derivatives 13a-c. To our knowledge only few examples of the reaction of nitriles with azides to yield tetrazoles have been reported in literature Compound 1 reacted with 1, 3-diphenyl-5- aminopyrazole [14a] to yield the pyrazolo [4, 5-d] 1, 2, 3-triazole derivative 15. On the other hand, the aminopyrazole 14b reacted under the same conditions to yield the tetrazene derivative 16. Under a variety of conditions l-phenyl-3-methyl-2-pyrazolin-5-one reacted with tosylazide to yield the hydrazo derivative 18. The formation of 18 is assumed to proceed via intermediacy of the diazo derivative 19 formed through the triazine 20 [c.f. chart 2]. In order to get evidence for this assumption the reaction of 17 with 1 was conducted in the presence of [3-naphthol. The coupling product 21 was isolated in addition to 18 and the azo derivative 22