Synthesis of 6-amino-2-aryl-1,2-dihydro-3H-pyrido[2,3-d]pyrimidin-4-one derivatives

This paper reports the synthesis of new pyrido[2,3-d]pyrimidin-4-one derivatives as diuretic agents. Starting with 1,2-dihydro-5-nitro-2-oxo-3-pyridinecarboxylic acid 1 , ethyl 2-ethoxy-5-nitro-3-pyridincarboxylate 4 was obtained. Compound 4 reacts with ammonia, methylamine or S-methylpseudothiourea to give the respective 2-amino-5-nitro-3-pyridinecarboxamide derivatives 5 and 6 or 2-methylthio-6-nitro-3H-pyrido[2,3-d]pyrimidin-4-one 8. Treating carboxamide 5 with arylaldehydes and zinc dichloride, new 2-aryl-1,2-dihydro-6-nitro-3H-pyrido[2,3-d]pyrimidin-4-ones 9 were synthetised. These compounds reduced with iron(II) hydroxide gave 6-amino-2-aryl-1,2-dihydro-3H-pyrido[2,3-d]pyrimidin-4-ones 10 as expected.     

Novel synthesis of 3-aryl-5,6-dihydropyridin-2(1H)-ones

Cyclization of N-3-oxoalkylamides of substituted phenylacetic acids under the influence of bases produces 3-aryl-substituted 5, 6-dihydropyridin-2(1H)-ones. Dehydrogenation of these latter compounds yields substituted pyridin-2(1H)-ones.Omsk State University, Omsk 644077. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 812–815 June, 1994. Original article submitted May 6, 1994.     

Synthesis of 2,3-dihydro-4(1H)-quinoline derivatives

N-Carboxyethyl-N-(3-R-phenyl)-ß-alanines were synthesized by the reaction of m-substituted anilines with acrylic acid; they were cyclized to the corresponding 2,3-dihydro-4(1H)-quinoline derivatives.Translated from Khimiva Geterotsiklicheskikh Soedinenii. No. 4, pp. 523–526, April, 1996.     

无溶剂条件下固相合成2,3-二芳基-2,3-二氢喹唑啉-4(1H)-酮

在NaOH存在下,无溶剂加热靛红酸酐和席夫碱,合成一系列2,3-二芳基-2,3-二氢喹唑啉-4(1H)-酮衍生物.该反应产率高,操作简单.反应中考察了不同席夫碱对反应的适用性,合成了16个产物.产物结构经IR,1HNMR,HRMS确证.     

Synthesis of 6-Alkylthio-5-carbamoyl-3-cyano-4-phenyl-3,4-dihydropyridin-2(1H)-ones

Condensation of ethyl benzylidenecyanoacetate with thiocarbamoylacetamide in the presence of an equimolar amount of piperidine produces piperidinium 5-carbamoyl-3-cyano-2-oxo-4-phenyl-3,4-dihydropyridine-6(1H)-thiolate, which is then used in synthesis of the corresponding 6-alkylthiosubstituted 3,4-dihydropyridin-2(1H)-ones. Dedicated to Professor Henk van der Plas on his 70th birthday. Latvian Institute of Organic Synthesis, Riga LV-1006 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 506–509, April, 1999.     

Difluoromethylation of 6-methyl-2-thioxo-2,3-dihydropyirimidin-4(1H)-one with chlorodifluoromethane

Russian Journal of Organic Chemistry -     

A Convenient Synthesis of N-Substituted 1,6-Dihydro-3(2H)-Pyridinones

N-Substituted 1,6-dihydro-3(2H)-pyridinones have been synthesised from N-substituted piperidine-3,5-diones via the methyl enol ethers. Reduction of the latter with sodium borohydride (NaBH₄) is described.     

Synthesis and constants of 6-nitro-2,3-dihydroquinolin-4(1h)-one

In the literature, there has appeared a communication [1] on the synthesis of 6-nitro-2, 3-dihydroquinolin-4(1H)-one (I) with mp 125–126C (2,4-dinitrophenylhydrazone, mp 269–270C) by the reaction of p-nitroaniline with acrylic acid. Quinolinone I with mp 232–234C (2,4-dinitrophenylhydrazone, mp 327–329C) was obtained by us by decarboxycyclization of N-(2-carboxy-4-nitrophenyl)--alanine in acetic anhydride in the presence of potassium acetate [2].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1390–1392, October, 1979.     

Synthesis and some properties of 4-alkyl-5-cyano-6-mercapto-3,4-dihydropyridin-2(1H)-ones

Condensation of propionic (or acetic) aldehyde, cyanothioacetamide, Meldrum's acid, andN-methylmorpholine occursvia the intermediate formation of the corresponding Michael adducts and yields 4-alkyl-5-cyano-6-mercapto-3,4-dihydropyridin-2(1H)-ones. The oxidation of the reaction products with DMSO and their alkylation were studied. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2016–2019, November, 1997.     

Synthesis and reactions of 4-aryl-1(2H) phthalazinones

The behavior of 4-aryl-1(2H)-phthalazinones ( 1a—c ) toward some electrophilic and nucleophilic reagents has been described with the aim of preparing some new phthalazinone derivatives of the expected pharmacological or biological activities.     

Conversion of 2-amino-2,3-dihydro-1H-isoindol-1-one into pyridazine a novel synthesis of 3-aryl-4(1H)-pyridazones

The title conversion was achieved by condensation of 2-Amino-2,3-dihydro-1H-isoindol 1-one with ethyl benzoyl or aceto/acetate followed by base-promoted rearrangement.     

Synthesis,antibacterial and antioxidant activity of novel 2,3-dihydroquinazolin-4(1H)-one derivatives of dehydroabietylamine diterpene

A series of novel 2,3-dihydroquinazolin-4(1H)-ones was synthesized by a three-component reaction between dehydroabietylamine (DHA) diterpene, isatoic anhydride and different aromatic aldehydes in the presence of a catalytic amount of p-toluenesulfonic acid (13 mol%). Diastereomeric products were separated by preparative thin-layer chromatography and their structures were characterized by ¹H and ¹³C NMR, HMQC, IR and HR-ESI-MS. Antioxidant activities of the synthesized compounds were assessed by two different methods including DPPH and β-carotene-linoleic acid bleaching assays. Antibacterial activities of the compounds were also evaluated against two Gram-positive and one Gram-negative bacterial strains and in the case of Bacillus cereus a considerable inhibitory effect (MIC 4–16 μg/ml) was observed.     

Synthesis of 3-methylquinazolin-4(3H)-one derivatives

Oxidation of 3-methyl-2-sulfanylquinazolin-4(3H)-one with chlorine dioxide under different conditions gave 2,2??-disulfanediylbis[3-methylquinazolin-4(3H)-one], 3-methyl-4-oxo-3,4-dihydroquinazoline-2-sulfonic acid, 3-methylquinazoline-2,4(1H,3H)-dione, 6-chloro-3-methylquinazoline-2,4(1H,3H)-dione, and N,N-diethyl-3-methyl-4-oxo-3,4-dihydroquinazoline-2-sulfonamide.     

Synthesis of 4-styryl-2,3-dihydro-1H-1,5-benzodiazepin-2-ones

4-Styryl-2,3-dihydro-1H-1,5-benzodiazepin-2-ones were synthesized and their structure was established by means of PMR spectra and mass spectroscopy.Dnepropetrovsk State University Named in Honor of 300th Anniversary of the Reunion of Ukraina and Russia, Dnepropetrovsk 320625. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1560–1562, November, 1987.     

Synthesis of 6-aryl-1,3-dimethyl-6,7-dihydro-6-azalumazin-7-(6H)ones and their conversion into 2-aryl-1,2,4-triazine-3,5-(2H,4H)odiones. A new synthesis of 1-aryl-6-azauracils

Treatment of 6-amino-5-arylazo-1,3-dimethyluracils with urea or N,N′-carbonyldiimidazole gave the respective 6-aryl-1,3-dimethyl-6,7-dihydro-6-azalumazin-7-(6H)ones, which were hydrolyzed with alkali to afford 2-aryl-2,3,4,5-tetrahydro-3,5-dioxo-1,2,4-triazine-6-carboxylic acids (1-aryl-6-azauracil-5-carboxylic acids). Thermal decomposition of these carboxylic acids gave the corresponding 2-aryl-1,2,4-triazine-3,5-(2H,4H)diones (1-aryl-6-azauracils). Methylation of the latter with methyl iodide gave the corresponding 2-aryl-4-methyl-1,2,4-triazine-3,5-(2H,4H)diones (1-aryl-3-methyl-6-azauracils).     

Synthesis of pyridin-2(1H)-one derivatives via enamine cyclization

The nucleophilic vinylic substitution reaction of the aliphatic enaminone 3-dimethylamino-2-formyl acrylonitrile 1 with the nucleophiles malononitrile and ethyl cyanoacetate produced the two unusual reaction adducts 3a and 3b in good to moderate yield under milder reaction conditions. Upon reaction with aromatic amines, these adducts yielded enamines 4 and 5, which eventually cyclized in the presence of base to produce the novel pyridin-2(1H)-one derivatives 8 and 9.     

Synthesis of 4-Amino-6-phenyl-3-thioxo-2,3-dihydro-1,2,4-triazine-5(4H)-one

Russian Journal of General Chemistry -