“One pot” synthesis of 2,9-disubstituted 8-azaadenines (3,5-disubstituted 7-amino-3H-1,2,3-triazolo[4,5-d]pyrimidines)

A new simple method for the synthesis of title compounds is described starting from malononitrile, benzyl-azide and an aliphatic or aromatic nitrile.     

A facile “one pot” synthesis of 2,9-disubstituted 8-azapurin-6-ones (3,5-disubstituted 7-hydroxy-3H-1,2,3-triazolo[4,5-d]pyrimidines)

A series of title compounds have been synthesized by utilising benzylazide, cyanoacetamide, ethyl or methyl esters of aliphatic or aromatic carboxylic acids and sodium ethoxide as catalyst.     

“One pot” synthesis of 2-substituted 9-(2′-hydroxy-3′-aminopropyl)-8-azahypoxanthines and 8-azaadenines (5-substituted 3-(2′-hydroxy-3′-aminopropyl) 7-amino and 7-hydroxy-3H-1,2,3-triazolo[4,5-d]pyrimidines)

An example of the generalization of the synthesis of 8-azahypoxanthines A and 8-azaadenines B , interesting from a medicinal point of view, is presented by utilizing l-amino-2-hydroxy-3-azidopropanes.     

Lactam and amide acetals. 52. Reaction of dimethylformamide diethylacetal with 2,2-dimethyl-4,6-dioxo-1,3-dioxane (Meldrum's acid)

Depending on the conditions of carrying out the reaction of dimethylformamide diethylacetal with the Meldrum's acid, either 2,2-dimethyl-4,6-dioxo-5-(N,N-dimethyl-aminomethylene)-1,3-dioxane or N,N,N¹N¹-tetramethylformamidinium salt of 2,2-dimethyl-4,6-dioxo-5-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)methylene-1,3-di-oxane are formed. The two compounds can react with primary amines to form N-substituted 2,2-dimethyl-4.,6-dioxo-5-aminomethylene-1,3-dioxanes.For Communication 51, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 184–187, February, 1988.     

Synthesis of 6-amino-1,2,3-triazolo[4,5-c] pyridin-4(5H)one (8-aza-3-deazaguanine) and 6-amino-1-(β-D-ribofuranosyl)-1,2,3-triazolo[4,5-c] pyridin-4(5H)one (8-Aza-3-deazaguanosine) via novel ring closure procedures

The total synthesis of 6-amino-1,2,3-triazolo[4,5-c]pyridin-4(5H)one (8-aza-3-deazaguanine, 3 ) and 6-amino-1-(β-D-ribofuranosyl)-1,2,3-triazolo[4,5-c]pyridin-4(5H)one (8-aza-3-deazaguano-sine, 22 ) has been described for the first time by a novel base-catalyzed ring closure of 4(5)-cyanomethyl-1,2,3-triazole-5(4)carboxamide (14) and methyl 5-cyanomethyl-1-(2,3,5-tri-O-ben-zoyl-β-D-ribofuranosyl)-1,2,3-triazole-4-carboxylate (17) , respectively. Under the catalysis of DBU, 2,4-dinitrophenylhydrazone of dimethyl 1,3-acetonedicarboxylate (7) was converted to methyl 5-methoxycarbonylmethyl-1-(2,4-dinitroanilino)-1,2,3-triazole-4-carboxylate (12) via dimethyl 2-diazo-3-iminoglutarate (8) . Catalytic reduction of 12 gave methyl 4(5)methoxycar-bonylmethyl-1,2,3-triazole-5(4)carboxylate (11) from which methyl 4(5)carbamoylmethyl-1,2,3-triazole-5(4)carboxylate (10) was obtained by ammonolysis. Dehydration of 10 provided methyl 4(5)cyanomethyl-1,2,3-triazole-5(4)carboxylate (13) which on amination gave 14 . The 1,2,3-triazole nucleosides 17, 18 and 19 were obtained from the stannic chloride-catalyzed condensation of the trimethylsilyl 13 and a fully acylated β-D-ribofuranose. The yield and ratio of the ribofuranosyl derivatives of 13 markedly depends on the ratio of stannic chloride used. The structures of the nucleosides 22 and 23 were established by a combination of NOE, ¹H-nmr and ¹³C-nmr spectroscopy.     

Regioselective synthesis of 9-substituted-8-azaguanines (5-amino-3-substituted-3,6-dihydro-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one)

By modifying previously described methods for the synthesis of 9-substituted-guanines from imidazoles, we have developed a new procedure for the regioselective synthesis of 9-substituted-8-azaguanines (5-amino-3-substituted-3,6-dihydro-7H-1,2,3-triazolo[4,5-d]pyrimidin-7-one) from triazoles in high yields. The method seems suitable for the introduction of a variety of substituents including sugars, carbocyclic, acyclic and carboacyclic chains.     

Synthesis, spectroscopic and DFT investigation of dimethyl-2-(5-acetyl-2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-3-(triphenylphosphinylidene)succinate

Dimethyl-2-(5-acetyl-2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-3-(triphenylphosphinylidene)succinate has been synthesized and characterized by elemental analysis, FT-IR and ¹H, ¹³C and ³¹P NMR. The vibrational wavenumbers, gauge including atomic orbital (GIAO) ¹H and ¹³C chemical shift values of title compound in the ground state have been computed with density functional theory method (DFT) and the B3LYP functional. The basis sets used are 6-311G(d,p) and 6-31G(d). The harmonic vibrational wavenumbers have been computed and the scaled values have been compared with the experimental FT-IR spectra. The complete assignments have been performed on basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. Most of the computed wavenumbers are found to be in good agreement with the observed spectrum.     

A novel π-donor–π-acceptor system: 1-(4,5-dimethyl-1,3-dithiol-2-ylidene)-1-ferrocenyl-3,3-dicyanopropene

The title compound was prepared by reacting the anion of malononitrile with the corresponding ethanal, and characterised by UV–vis absorption spectroscopy, cyclic voltammetry and X-ray crystallography. Attachment of an additional ferrocenyl donor group to the π-donor–π-acceptor system does not enhance intramolecular charge transfer, because its bulk distorts the planarity of the conjugated chain.     

利用串联的氮杂Wittig反应方便合成3-[取代吡啶(噻唑)甲基]-1,2,3-三唑[4,5-d]嘧啶-7-酮及其除草活性

用串联的氮杂Wittig关环反应合成了一系列3-[取代吡啶(嘧啶)甲基]-1,2,3-三唑[4,5-d]嘧啶-7-酮.膦亚胺4和芳基异氰酸酯发生氮杂Wittig反应生成碳二亚胺5,继而在乙醇钠催化下与各种脂肪伯胺关环,以较好的收率得到目标产物7.初步生物活性测试结果表明:该系列部分化合物在100 mg/L的浓度下对双子叶植物油菜显示出较好的除草活性.