Yu. M. Shafran

Heterocyclic compounds containing diazo and cyano groups. 1. Diazoacetonitrile derivatives in the synthesis of 5-halo-1H-1,2,3-triazoles

Carbonyl-substituted derivatives of diazoacetonitrile have been obtained by the diazotization of amines and by diazo-group transfer which, under the action of hydrogen halide, have been converted into 4-carbonyl-substituted 5-halo-1H-1,2, 3-triazoles. The structures of these compounds have been confirmed by mass spectrometry and independent synthesis.

Heterocyclization of compounds containing diazo and cyano groups. 3. Two pathways in the cyclization of 2-diazo-2-cyanoacetic acid derivatives under the influence of bases

Abstract1,2,3-Triazol-5-olates are formed in the reaction of diazomalonodiamide and 2-diazo-2-cyanoacetic acid amide and N-methylamide with sodium ethoxide, triethylamine, and ammonia. The products of the reaction of 2-diazo-2-cyanoacetamide with primary amines are mixtures of 4-cyano-1,2,3-triazol-5-olates and 5-amino-1-alkyl-1,2,3-triazole-4-carboxamides.

ANOMALOUS REARRANGEMENT OF 1,2,3-THIADIAZOLES TO 1,2,3-TRIAZOLES

The rearrangement of 5-amino-1,2,3-thiadiazoles under the influence of halogen-containing oxidizing to bis(triazolyl) disulfides was observed. Ammonia reduces the disulfides obtained to 5-mercapto-1,2,3-triazoles.

Heterocyclization of compounds containing diazo and cyano groups. 2. Synthesis and recyclization of 4-substituted 5-amino-1,2,3-thiadiazoles

The reaction of carbonyl derivatives of diazoacetonitrile with hydrogen sulfide in the presence of triethylamine yields 4-substituted 5-amino-1,2,3-triadiazoles. Under analogous conditions, hydrogen selenide and ethyl mercaptan reduce the starting diazo compounds to hydrazones. Thiadiazoles are recyclized to 4-substituted 5-mercapto-1,2,3-triazoles by the action of bases.

Mass-spectrometric study of the cyclization of diazo compounds. 10. 2-Diazomalonic acid amides. Mass spectra of the negative ions

The mass spectra of the negative ions of the dissociative resonance capture of electrons of diazo amides and the isomeric triazoles were studied. The molecular negative ions of these compounds are unstable and do not undergo interisomerization. The principal fragmentation process involves the elimination of a molecule of nitrogen and transformation of the resulting [M-N2]− ions to the heterocyclic form, which is the same for the two isomers.

Mass-spectrometric study of isomeric 5-amino-1,2,3-thiadiazoles and 5-mercapto-1,2,3-triazoles

The behavior of the isomeric 5-amino-1,2,3-thiadiazoles and 5-mercapto-1,2,3-triazoles under electron impact was studied. It was shown that mass spectrometry can serve as a rapid and reliable method for the identification of these compounds. Key factors in the assignment of a compound to one or the other class are the peaks of the [M-N2]+ ions, which are more intense in the case of the thiadiazoles, and the ions determined by the decomposition of the prototropic forms of the triazoles. The compositions of the ions were determined by the high-resolution mass spectra.

Mass-spectrometric study of the cyclization of diazo compounds. 9. 2-Diazo-2-cyanoacetamides

An analysis of the electron impact mass-spectra of 2-diazo-2-cyanoacetamides and the 4-cyano-5-hydroxy-1,2,3-triazoles isomeric to them, showed that the molecular ions of these compounds do not isomerize one into another. The diazo compounds decompose, undergoing a Wolff rearrangement. To study the fragmentation of the diazoamides, one can use the crystalline adducts of these diazo compounds with triphenylphosphine, and to study the fragmentation of the triazoles, their salts with aliphatic amines.

Synthesis and properties of analogs of 5(or 4)-aminoimidazole-4(or 5)-carboxamide (aica) and purines. 12. Investigation of the interaction of 4-chloroimidazo[4,5-d]-1,2,3-triazine with nucleophiles

The reactions of 4-chloroimidazo[4,5-d]-1,2,3-triazine with a number of nucleophilic reagents have been studied. Either replacement of the chlorine atom in position 4 of the 1,2,3-triazine ring or opening of the triazine ring with the formation of products of the interaction of the intermediate 5-diazoimidazole-4-carbonitrile with these nucleophiles occurs, depending on the nucleophilicity of the reagent.