A novel synthesis of flourinated pyrido [2,3-d] pyrimidine derivatives

Flourinated 4-imino-3,5,7-trisubstituted-pyrido [2,3-d] pyrimidine-2(1H) thiones have been synthesised in good yields by the reaction of 2-amino-3-cyano-4,6- disubstituted-pyridines with various arylisothiocyanates. These new type of products have been characterised by elemental analysis, IR, ¹H and ¹⁹F NMR spectral studies.     

The synthesis and stereochemistry of some pyrido[3,4-d]carbazole derivatives

Pyrido[3,4-d]carbazole derivatives have been synthesised from N-acetyl-5-oxodecahydro-isoquinoline by the Fischer indole synthesis, and their stereochemistry established by ¹H-NMR spectroscopy. In contrast to experience with simpler systems, cyclisation in acetic acid gave only the alternative pyrido[3,4-a]-carbazole, and the desired pyrido[3,4-d]carbazole formation occurred only in the presence of sodium acetate.     

Synthesis of pyrido[3,4-d] benzazepines

The synthesis of some derivatives of the novel heterocyclic ring system pyrido[3,4-d][1]benzazepine is reported. Thus, pyrido[3,4-d][1]benzazepin-7-one 6 was prepared by cyclisation of the Michael adduct 5 with ammonium ferric sulfate. Reaction of 6 with phosphorus pentasulfide gave the thiolactam 7 , which after methylation and subsequent reaction with amines furnished the amidines 10 .     

Calculation of electronic spectra of pyrido [2,3-d]pyridazine and pyrido[3,4-d]pyridazine

The electronic spectra of pyrido[2,3-d]pyridazine and pyrido[3,4-d]pyridazine have been calculated by the P method and the RP method previously used for azines. The results are in good agreement with experimental data and with the previous conclusions.     

Synthesis of new pyrido[2,3-d]pyrimidine derivatives

The mutual condensation of 4-aminouracil or 2,4-diamino-6-hydroxypyrimidine with bisacetonitrile and aldehydes was used to synthesize 2,4-dioxo-5-R-7-methyl-6-cyano-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine and 2-amino-4-oxo-5-R-7-methyl-6-cyano-3,4,5,8-tetrahydropyrido[2,3-d]pyrimidine derivatives, which were oxidized with chromic anhydride to the corresponding 2,4-dioxo-5-R-7-inethyl-6-eyano-1,2,3,4-tetrahydropyrido[2,3-d]pyrimidine and 2-amino-4-oxo-5-R-7-methyl-6-cyano-3,4-dihydro[2,3-d]pyrimidines. The IR and UV spectra of the synthesized compounds were recorded.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 422–425, March, 1972.     

Solvent-free combinatorial synthesis of tetrazolo[1,5-a]thiopyrano[3,4-d]pyrimidine derivatives

A series of novel tetrazolo[1,5-a]thiopyrano[3,4-d]pyrimidine derivatives were synthesized by reaction of aryl aldehyde, 2H-thiopyran-3,5(4H,6H)-dione, and 5-aminotetrazole under solvent-free conditions. The features of this procedure are mild reaction conditions, high yields, and operational simplicity.     

The synthesis of substituted pyrido[1′,2′:1,5]pyrazolo[3,4-d]pyrimidines

A convenient synthesis of derivatives of the pyrido[1′,2′:1,5]pyrazolo[3,4-d]pyrimidine ring system from readily available 2-amino-3-cyano-5,7-diphenylpyrazolo[1,5-a]pyridine I and carbon disulfide, aryl isothiocyanates or nitriles is described. Derivatives of compound I undergo cyclization to the titled ring system by action of dimethylformamide dimethylacetal or hydrogen sulfide followed by treatment with triethylamine.     

Nitroxyl derivatives of pyrazolo [3,4-d]pyrimidine

Conclusions Pyrazolo[3,4-d]pyrimidine nitroxyl derivatives having different distances between the paramagnetic center and the pyrazolopyrimidine ring have been prepared for the first time.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2763–2766, December, 1982.     

Facile one-pot synthesis of pyrido[2,3-d]pyrimidine derivatives over ZrO2 nanoparticles catalyst

An efficient synthesis of hexahydropyrido[2,3-d]pyrimidinetrione derivatives is achieved via tandem Knoevenagel-Michael addition of aromatic aldehydes,methylcyanoacetate and 4（6）-aminouracil in solvent-free conditions in the presence of 10 mol%of ZrO₂ nanoparticles（ZrO₂ NPs） as a heterogenous catalyst.The procedure is formed in high yields,short reaction time and an environmentally friendly specificity.     

Regioselective synthesis of pyrido[2,3-d]pyrimidines

The reaction of diethyl ethoxymethylenemalonate ( 1 ) and 6-amino-1,3-dimethyluracil ( 2 ) was determined to be regioselective. Under acidic conditions the product was the previously isolated 7-oxopyrido[2,3-d]pyrimidine ( 3 ), while in the presence of one equivalent of base followed by thermal cyclization, the isomeric 5-oxopyrido[2,3-d]pyrimidine ( 5 ) is formed.     

An efficient route for the synthesis of a new class of pyrido[2,3-d]pyrimidine derivatives

A new reaction of 4-arylidene-3-methylisoxazol-5(4H)-one or 4-arylidene-2-phenyloxazol-5(4H)-one with 2,6-diaminopyrimidin-4(3H)-one is described and a number of new pyrido[2,3-d]pyrimidine-4,7-dione derivatives are synthesized. This protocol has the advantages of good yields, broad substrate scope and simple work-up.     

5,6,7,8-四氢吡啶并[3,4-d]嘧啶衍生物的合成

以苄胺为原料,经过取代,缩合,水解,脱保护等步骤,设计合成了一系列新型的5,6,7,8-四氢吡啶并[3,4-d]嘧啶类化合物。通过1H NMR,13C NMR,MS和元素分析确证了其结构。并且对其体外抗肿瘤活性进行了研究,发现该类化合物对乳腺癌细胞MCF-7具有一定的抑制活性,其中化合物10a和10d的抑制活性达到了中效水平。     

A highly fluorescent nucleoside analog based on thieno[3,4-d]pyrimidine senses mismatched pairing

A highly emissive nucleobase analog, based on a thieno[3,4-d]pyrimidine core, is enzymatically incorporated into RNA oilgonucleotides that function as base discriminating fluorescent probes.     

Purine acyclic nucleosides. Unambiguous synthesis of acyclovir via a furazano[3,4-d]pyrimidine

Acyclovir was synthesized in five steps from 7-formamido-5-methylthiofurazano[3,4-d]pyrimidine 2 . Alkylation of 2 with 2-(benzoyloxy)ethoxymethyl chloride, followed by reductive cleavage of the furazan ring gave 9-[[2-(benzoyloxy)ethoxy]methyl]-2-(methylthio)adenine 5 . Hydrolysis of the 6-amino group of 5 , followed by amination of 7 with ammonia gave 9-[(2-hydroxyethoxy)methyl]guanine ( 1 , acyclovir).     

Catalyst free synthesis of fused pyrido[2,3-d]pyrimidines and pyrazolo[3,4-b]pyridines in water

A one-pot,three-component condensation reaction of an aldehyde,benzoyl acetonitrile(3-oxo-3-phenylpropane nitrile) and 6- amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione or 3-methyl-1-phenyl-1H-pyrazol-5-amine in water to give fused pyrido[2,3- d]pyrimidines and pyrazolo[3,4-b]pyridines in high yields without any catalyst,is described.     

新型碱性离子液体催化剂高效催化合成吡喃酮[2,3-d]嘧啶酮和[2,3-d]嘧啶衍生物

制备了碱性离子液体1,1'-(丁烷-1,4-二基)双(1,4-二氮杂二环[2.2.2]辛烷-1-ium)羟化物,并采用红外光谱、1H核磁共振谱和pH值分析对其进行了表征.然后将它用于室温研磨条件下高效催化合成吡喃酮[2,3-d]嘧啶酮和[2,3-d]嘧啶.该法步骤简单,反应时间短,产物收率高,无需柱色谱分离,原料易得,且可回收利用.     

An improved synthesis of pyrido[2,3-d]pyrimidines

An improved and efficient synthesis of 1,3-dialkylpyrido[2,3-d]pyrimidine-2,4-(1H,3H)-diones from 6-methylaminouracils and methyl propiolate or diethyl ethoxymethylenemalonate is described.