Pyrano[4,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidinium salts

5-Aroyl-1,3,6-trimethyluracils were converted to pyrano[4,3-d]pyrimidinium salts. Reactions of the salts obtained with ammonia, primary amines, and hydrazine were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2251–2257, November, 2007.     

Pyrano[4,3-d]pyrimidinium salts 4. Transformations of 5,7-diaryl-1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium bromides under the action of phenylhydrazines and aromatic acid hydrazides

Reactions of 5,7-diaryl-1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium bromides with phenylhydrazines and aromatic acid hydrazides have been studied. The reaction of the salts indicated with phenylhydrazine at ∼20 °C results in the pyrylium ring opening, whereas elevated temperature leads to recyclization products, i.e., 1,3-dimethylpyrido[4,3-d]pyrimidine-2,4(1H,3H)-diones. The reactions of the starting bromides with m-carboxyphenylhydrazine and aromatic acid hydrazides lead to 6-(R-amino)-1,3-dimethyl-2,4-dioxo-1H,3H-pyrido[4,3-d]-pyrimidinium salts.     

Pyrano[4,3-d]pyrimidinium salts 3. Reactions of 1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium salts with azomethines

Reactions of 1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium salts with azomethines have been studied. The reactions lead to 1,3-dimethyl-2,4-dioxo-1H,3H-pyrido-[4,3-d]pyrimidinium salts and aromatic aldehydes.     

Synthesis of pyrazolo[4,3-<Emphasis Type="Italic">e</Emphasis>][1,2,4]triazolo[4,3-<Emphasis Type="Italic">c</Emphasis>]pyrimidines

Starting from 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones, a synthesis pathway to the tricyclic pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines is described. Reaction of 1,5-dihydro-4H-pyrazolo[3,4-d] pyrimidin-4-ones with phosphoryl chloride afforded the corresponding 4-chloro-1H-pyrazolo[3,4-d]pyrimidines. Treatment of these compounds with hydrazine hydrate at reflux temperature gave the hydrazino derivatives, which were subsequently cyclized to the titled compounds on heating with orthoesters in ethanol. Correspondence: Abolghasem Davoodnia, Department of Chemistry, School of Sciences, Islamic Azad University, Mashhad Branch, Mashhad 91735-413, Iran.     

Reaction of 6-amino-1,3-dimethyluracil with hexafluoroacetone and ethyl trifluoropyruvate benzoylimines

Heating of 6-amino-1,3-dimethyluracil with hexafluoroacetone and ethyl trifluoropyruvate benzoylimines in DMF in the presence of Et₃N results in 1,3-dimethyl-7-phenyl-5,5-bis(trifluoromethyl)-1,2,3,4,5,8-hexahydropyrimido[4,5-d]pyrimidine-2,4-dione and 5-benzoylamido-1,3-dimethyl-5-trifluoromethyl-1,2,3,4,5,6-hexahydropyrrolo[2,3-d]pyrimidine-2,4,6-trione, respectively.     

Nitropyrazoles

A method of synthesizing nitro derivatives of lH,4H-pyrazolo[4,3-c]pyrazole is developed, and some of its transformations are studied. 3-Methyl-6-nitro-, 3-carboxy(methoxy-carbonyl, carbamoyl)-6-nitro-, 3-amino-6-nitro-, 3-nitro-, 3,6-dinitro-, 1,4-diacetonyl-3,6-dinitro-, and lH,4H-3-aminopyrazolo[4,3-c]pyrazoles were obtained from 1H,4H-3 -methylpyrazolo[4,3-c]pyrazole. Unsubstituted 1H,4H-pyrazolo[4,3-c]pyrazole, the first member of this series, was obtained for the first time. The compounds prepared were characterized by¹H,¹³C,¹⁴N, and¹⁵N NMR spectroscopy. NH-Acidity and basicity of the series of pyrazolo[4,3-c]pyrazoles synthesized is studied and the effect of the fused pyrazole ring on these properties is examined.Deceased March 18, 1989.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1108–1113, June, 1993.     

[3,4]-annulated pyrroles 1. Polynuclear heterocyclic systems based on pyrrolo[3,4-d]pyrimidine-2,4-dione

The intramolecular electrophilic substitution in 6-functionalized 1,3-dimethyl-1H-pyrrolo[3,4-d]pyrimidine-2,4(3H,6H)-diones was used for the synthesis of pyrimido[4′,5′:3,4]-pyrrolo[1,2-a]quinoxaline-8,10(7H,9H)-dione, pyrimido[4′,5′:3,4]pyrrolo[2,1-c][1,2,4]benzo-triazine-8,10(7H,9H)-dione, and 2H-pyrimido[4′,5′:3,4]pyrrolo[1,2-a]indole-2,4,11(1H, 3H)-trione derivatives. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2180–2185, December, 2006.     

Synthesis and structure of some thienopyrimidine derivatives

A series of substituted thieno[2,3-d]pyrimidines was synthesized starting from ethyl-2-amino-4-isopropylthiophene-3-carboxlate. Reaction of 2-hydrazino-5-isopropyl-thieno[2,3-d]pyrimidin-4(3H)-one and its 3-methyl analogue with different reagents afforded thieno[2,3-d]triazolo[4,3-a]pyrimidines and thieno[3,2-e]triazolo[4,3-a]pyrimidines, beside open chain derivatives. Correspondence: Atef A. Hamed, Department of Chemistry, Faculty of Science, Menoufia University, Shebin El Koam, Egypt.     

Construction of a pyrido[4,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine system on the basis of <Emphasis Type="Italic">N</Emphasis>-cyanobenzamidine and diethyl acetone-1,3-dicarboxylate

Nickel acetate promoted reaction of diethyl acetone-1,3-dicarboxylate with N-cyanobenzamidine led to ethyl 4-amino-6-ethoxycarbonylmethyl-2-phenylpyrimidine-5-carboxylate, upon treatment of which with RNH₂, the corresponding 6-(carbamoylmethyl)pyrimidines were obtained. Cyclization of the latter upon treatment with MeONa afforded 6-R-4-amino-7-hydroxy-2-phenylpyrido[4,3-d]pyrimidin-5(6H)-ones. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2212–2214, November, 2007.     

Synthesis of novel 2,3-substituted-2,4-dihydro-pyrazolo[4,3-d]pyrimidine-5,7-diones

Novel 2,3-substituted-2,4-dihydro-pyrazolo[4,3-d]pyrimidine-5,7-diones were successfully synthesized with moderate to good yields using a new synthetic approach. The structures of the regio-isomers in this series were determined by single crystal X-ray analysis and NMR spectra.     

Condensed Pyridopyrimidines. 7. Synthesis of Condensed Triazolo[4,3-c]- and Tetrazolo[1,5-c]pyrimidines

Novel dihydro-5H-pyrano[3',4':5',6']pyrido[2,3-d]-1,2,4-triazolo[4,3-c]pyrimidines and 1,2,3,4-tetrazolo[1,5-c]pyrimidines have been synthesized from 2-amino-3-cyano-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]pyridine.     

Novel Synthesis of 1,8-Alkanopyrido[3,4-d]pyridazine: a New Ring System

Cycloalkylidenemalononitriles couple with various diazonium salts to yield the corresponding cycloalkeno[c]pyridazines, which react with trichloroacetonitrile to give the 1,8-alkanopyrido[3,4-d]pyridazines. The reaction of cycloalkenopyridazines with DMF dimethylacetal gives enamine derivatives, which can be converted to 1,8-alkanopyrido[3,4-d]pyridazines via treating with hydrazine hydrate or aromatic amines. Substituted cycloalkenopyridines react with diazoaminobenzene to afford the corresponding 1,8-alkanopyridopyridazines.     

Synthesis and properties of pyrimido[4,5-<Emphasis Type="Italic">a</Emphasis>]- and pyrido[4,3-<Emphasis Type="Italic">a</Emphasis>]carbazole derivatives

Methods for the synthesis of substituted pyrimido [4,5-a]- and pyrido[4,3-a]carbazoles were proposed. Condensation of 2-(dimethylaminomethylene)-6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-one with guanidine and thiourea afforded 2-amino-8-methyl-6,11-dihydro-5H-pyrimido[4,5-a]carbazole and 8-methyl-3,5,6,11-tetrahydro-2H-pyrimido[4,5-a]carbazole-2-thione, respectively. The reaction of cyano(6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)acetamide with dimethylformamide dimethyl acetal gave N-(dimethylamino-methylene)cyano(6-methyl-2,3,4,9-tetrahydro-1H-carbazol-1-ylidene)acetamide. Cyclization of the latter yielded 1-cyano-8-methyl-3,5,6,11-tetrahydro-2H-pyrido[4,3-a]carbazol-2-one.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2740–2744, December, 2004.     

2-胺基(芳氧基)-5,8,9-三甲基噻吩并吡啶并[4,3-d]嘧啶-4(3H)-酮的合成和生物活性

利用串联Aza-Wittig法合成了两类共计16个未见文献报道的噻吩并吡啶并嘧啶类化合物, 通过IR, ¹H NMR, EI-MS, 元素分析等方法对所合成的化合物进行了结构表征, 化合物II-1还通过了X单晶衍射的进一步确证. 并初步测定了所合成化合物的杀虫、杀菌和除草活性. 结果表明: 所测化合物的杀虫活性较差, 但大部分化合物具有一定的除草活性和良好的杀菌活性.     

Synthesis of Precursors of Heterocyclic cis-β-Amino Alcohols by Intramolecular Amidoalkylation of 4-Hydroxyoxazolidin-2-ones

The reaction of intramolecular amidoalkylation of 4-hydroxyoxazolidin-2-ones leads to formation of novel and rare heterocyclic systems: substituted 1,5,6,10b-tetrahydro[1,3]oxazolo[4,3-a]isoquinolin-3-ones, 3a,4,5,10b-tetrahydro[1,3]dioxolo[4',5':6,7]naphtho[1,2-d][1,3]oxazol-2(1H)-ones, and 5,6,10,10a-tetrahydro-1H-di[1,3]oxazolo[3,4-d:4,3-g][1,4]diazepine-3,8-diones. Mild reaction conditions and the simplicity of isolation of the compounds formed make it possible to obtain the indicated heterocycles in high yields.     

Transformations of <Emphasis Type="Italic">ortho</Emphasis>-methoxyaryl(hetaryl)carboxamides into quinazolin-4-one and pyrido[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4-one derivatives

ortho-Chloroaryl(hetaryl)carboxamides containing one or two nitro groups at positions 3 and/or 5 of the ring undergo condensation accompanied by the pyrimidine ring closure on refluxing in an excess of sodium methoxide to form bicyclic products, viz., quinazolin-4-one, pyrido[2,3-d]pyrimidin-4-one, and pyrido[4,3-d]pyrimidin-4-one derivatives. The scheme of cyclization processes was proposed. The structures of the reaction products were confirmed by a number of physicochemical data, including X-ray diffraction analysis. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1851–1858, August, 2005.     

Purines, pyrimidines, and related fused systems. 21. Oxidative amination of 3-chloro-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-dione

Oxidative amination of 3-chloro-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-dione with primary alkylamines and potassium amide in liquid ammonia gives rise to the corresponding 4-amino derivatives as the major products. The reactions with acyclic secondary amines are accompanied by annelation of the pyrrole moiety to the starting heterosystem to form 1-R-3-R"-6,8-dimethylpyrrolo[2",3";3,4]pyrimido[4,5-c]pyridazine-7,9(6H,8H)-diones. The reaction with piperidine as the aminating agent occurs exclusively as aminodehalogenation. The Sonogashira cross-coupling of 4-amino-3-chloro-6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones with terminal alkynes affords 1-R-2-R"-6,8-dimethylpyrrolo[3",2";3,4]pyrimido[4,5-c]pyridazine-7,9(6H,8H)-diones.     

Synthesis and properties of 1,2,4-triazolo[4,3-d]-1,2,4-triazolo-[3,4-f]furazano[3,4-b]pyrazines

New methods for the synthesis of 1,2,4-triazolo[4,3-d]-1,2,4-triazolo[3,4-f]furazano[3,4-b]pyrazines with functional substituents of various types are proposed and some properties of these compounds are studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1776–1778, October, 1993.     

Pyrrolopyrimidines. 5. Reaction of 6-Amino-1,3-dimethylpyrrolo[3,4-d]pyrimidine-2,4(1H,3H)-diones with 1,3-Diketones

The reaction of 6-amino-1,3-dimethylpyrrolo[3,4-d]pyrimidine-2,4-dione with 1,3-diketones leads to formation of predominantly pyrimido[4',5':3,4]pyrrolo[1,2-b]pyridazine-2,4(1H,3H)-diones and, to a lesser extent, pyrimido[5',4':3,4]pyrrolo[1,2-b]pyridazine-1,3(2H,4H)-diones. The ease and direction of the cyclization reaction suggests a very -electron rich pyrrole ring in the initial state, especially in the position 7.     

Ionic Liquid Promoted One-Pot Synthesis of Furo[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine-2,4(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>)-diones

Summary. The three-component condensation of aldehyde, N,N′-dimethylbarbituric acid and alkyl or aryl isocyanide afforded the corresponding furo[2,3-d]pyrimidine-2,4(1H,3H)-diones in 1-butyl-3-methylimidazolium bromide as an ionic liquid in high yields at room temperature within several minutes.