Cyclocondensation of α-acylacetamidines with esters of 2-fluoro-5-nitrobenzoic and 4-chloro-2-methyl-5-pyrimidinecarboxylic acids

The cyclocondensation of α-acylacetamidines with esters of 2-fluoro-5-nitrobenzoic and 4-chloro-2-methyl-5-pyrimidinecarboxylic acids leads to condensed azines. The reaction proceeds chemoselectively such that the α-carbon atom of the amidine replaces the halogen atom in the aromatic ring, while the amino group reacts with the ester group. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 589–594, April, 2008.     

Reaction of thiazolidinethiones with hydrazine hydrate

Thiazolidinethiones react with hydrazine hydrate to give bicyclic compounds with a bridge sulfur atom. The bicyclic structure of the reaction products is confirmed by data from¹H NMR and IR spectroscopy. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 171–172, January, 1998.     

Reaction of tetracyanocyclopropyl ketones with hydrazine hydrate

The reaction of 2,2,3,3-tetracyanocyclopropyl ketones with hydrazine involved the addition at the carbonyl and cyano groups and resulted in the formation of previously unknown polycyclic systems whose common feature was the presence in the structure of a pyridazine ring. In the general case 3-substituted 6-amino-8-oxo-4,5,7-tptriazatricyclo[4.3.0.0^2.9]-non-3-ene-1,9-dicarbonitriles were obtained. The reaction with 3-pivaloylcyclopropane-1,1,2,2-tetracarbonitrile took another route with the opening of the three-membered ring and the formation of 3-amino-7a-tert-butyl-6-oxo-5,6,7,7a-tetrahydro-4aH-pyrrolo[2,3-c]pyridazine-4,5-dicarbonitrile.     

Reaction of 9-substituted 1-aminoadenine with hydrazine

Reaction of 9-substituted (methyl or benzyl) 1-aminoadenines 1 with hydrazine afforded 9-substituted 6-hydrazinopurines 2 and 1-substituted 5-ammo-4-(4-amino-1,2,4-triazol-3-yl)imidazole ( 4 ). The product ratio of 2 to 4 rose with increasing amounts of methanol used as the solvent. When the same reaction was carried out using 1,9-dimethyladenine instead of 1 , compounds 2 and 4 were also obtained with N⁶,9-dimethyladenine. A possible mechanism for formation of 2 and 4 is discussed.     

Reaction of methyl 4,9-dioxobicyclo[3.3.1]nonane-2-carboxylate with hydrazine hydrate

Vilnius University, Vilnius 2734. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 416–417, March, 1995. Original article submitted January 20, 1995.     

Dealkylation with hydrazine hydrate

Cleavage of one alkyl group occurs in the reaction of 4-amino-3,5-di(alkylthio)-1,2,4-triazoles with hydrazine hydrate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1708–1710, December, 1973.     

Synthesis of 5-substituted cyanofurans and their reaction with hydrazine

Based on the Schmidt reaction, a new method has been developed for the preparation of nitriles in furan series from the corresponding furfural derivatives. Depending on conditions, the reaction of 5-substituted cyanofurans with hydrazine leads to amidrazones, N-aminotriazoles, or 1,2,4,5-dihydrotetrazines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 181–186, February, 1986.     

2-acyl(aroyl)-1,1,3,3-tetracyanopropenides: V. Reaction with hydrazine hydrate

Reactions of 2-acyl(aroyl)-1,1,3,3-tetracyanopropenides with hydrazine hydrate followed by neutralization led to the formation of 2-amino-4-[hydrazono(aryl)methyl]-2-oxo-1,2-dihydropyridine-3,5-dicarbonitriles.     

Reaction of 1-germatranol hydrate with carboxylic acids

Reaction of 1-germatranol hydrate with carboxylic acids RCOOH (R = ClCH₂, PhCH=CH, Ph, 2-FC₆H₄, 3-BrC₆H₄, 3-HOC₆H₄, 3-EtOC₆H₄) in protic (CH₃OH, iso-C₅H₁₁OH) and aprotic polar solvent (CH₃CN) is studied. 1-Acyloxygermatranes RC(O)OGe(OCH{in2}CH{in2}){in3}N are formed in yields from 11 to ~100 % depending on the nature of the acid, solvent, duration of the process and the method of its completion. The reaction is the most effective in acetonitrile. Its topochemical completion (heating of the reaction residue in a vacuum) increases the yield of 1-acyloxygermatranes.     

Preparation of 5-substituted 3-aminofuran-2-carboxylate esters

[reaction: see text] An efficient method for the preparation of 3-aminofuran-2-carboxylate esters has been developed. This method is based on the reaction of an alpha-cyanoketone with ethyl glyoxylate under Mitsunobu conditions to produce a vinyl ether in good yield. Subsequent treatment of the vinyl ether with sodium hydride afforded the 3-aminofuran. It was also found that a one-pot procedure using the Mitsunobu reaction followed by cyclization afforded the 3-aminofuran in comparable yield. Currently, this method is limited to the synthesis of 5-alkyl-, 5-aryl-, and 4,5-fused bicyclic furans.     

Reduction of 2-amino-3- and -5-nitropyridine derivatives with hydrazine hydrate

The reactions of 2-amino-3-nitropyridine and 2-amino-5-nitropyridine with hydrazine hydrate resulted in elimination of the amino group and reduction of the nitro group with formation of 3-aminopyridine. A probable reaction mechanism involves addition of hydrazine hydrate at the N-C² bond, followed by elimination of ammonia and reduction of the nitro group to amino. 2-Amino-4-methyl-3-nitropyridine and 2-amino-5-methyl-3-nitropyridine reacted with hydrazine hydrate in a similar way.     

Catalytic amination of 2-substituted pyridines with hydrazine derivatives

[reaction in text] Protected pyridylhydrazine derivatives were prepared in a one-step palladium-catalyzed amination reaction using chelating phosphine ligands. 2-Pyridyl chlorides, bromides, and triflates were effective electrophiles in these reactions. Di-tert-butyl hydrazodiformate was an excellent hydrazine substrate, and the resulting products were deprotected under mild conditions. Catalytic amination provides a direct route to protected bifunctional hydrazinopyridine linkers that are suitable for metal-bioconjugate syntheses.     

Reaction of 2-aminopyrimidines with αhalocarboxylic acids and their esters

N-Pyrimidylcarboxylic acids and their esters, which can be cyclized to tetrahydromidazo-[1,2-a]pyrimidine-2,5-diones, are formed from 2-aminopyrimidine and its C-substituted derivatives by reaction with -halo acids and their esters under mild conditions. Alkylation proceeds at the N₁ and N₃ atoms of the pyrimidine ring during the action of unsymmetrical 2-aminopyrimidines with -halo acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1140–1142, August, 1974.     

Reaction of 3,3-dialkyl-6-trifluoromethyl-2,3-dihydro-4-pyrones with hydrazine hydrate

3,3-Dialkyl-2,3-dihydro-6-trifluoromethyl-4-pyrones react with hydrazine hydrate to give 2-hydrazino-2-trifluoromethyl-4-tetrahydropyrone hydrazones. When heated, the latter are transformed into 3(5)-(2-hydroxyethyl)-5(3)-trifluoromethylpyrazoles, while their treatment with HCl in ether leads to 3,3-dialkyl-2,3-dihydro-6-trifluoromethyl-4-pyrone azines.     

Reaction of 5-substituted 4,6-dichloro-2-aminopyrimidines with oxalyl chloride

The reaction of 5-substituted 4,6-dichloro-2-aminopyrimidines with oxalyl chloride gives 2-isocyanatopyrimidines, the structures of which were proved by chemical means and the IR, PMR, and ³⁵Cl nuclear quadrupole resonance spectra. The intermediate pyrimidinyloxamic acid chlorides were not isolated; this is evidently explained by the low basicities of 2-amino-pyrimidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1248–1251, September, 1977.