Synthesis and some properties of 4-phosphorylated derivatives of 5-mercapto-1,3-oxazoles

Various approaches to the synthesis of new derivatives of diethyl 5-mercapto-2-R-1,3-oxazole-4-ylphosphonates were considered. The behavior of these compounds in the presence of mineral acids and alkalis resulting in the synthesis of previously unknown 5-mercapto-2-R-1,3-oxazole-4-ylphosphonic acids was studied.     

Stereoselective photo[4+2]cycloadditions of 2-pyrone-5-carboxylates with maleimides in the solid state and in solution

Solid state photoreactions and thermal reactions of 2-pyrone-5-carboxylates with maleimides gave endo-[4+2]cycloadducts, while the sensitized photoreactions gave exo-[4+2]cycloadducts stereo-selectively.     

4-Hydroxy-2-quinolones. 84. Synthesis of 5-R-5H-5,7a,12-Triazabenzo[a]anthracene-6,7-diones

2-Aminopyridines react under thermolysis conditions with ethyl 1-R-4-chloro-2-oxoquinoline-3-carboxylates exclusively in the imino form to give the corresponding 5-R-5H-5,7a,12-triazabenzo[a]anthracene-6,7-diones and 4-(pyridyl-2-amino)-1-R-quinolin-2-ones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1060–1070, July, 2005.     

Sonochemical synthesis of Biginelli compounds

The ultrasound effect accelerates the Biginelli reaction 40 and more times. A sonochemical method for the synthesis of ethyl 4-R-6-methyl-2-oxo- and 4-R-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylates was developed. The target products were obtained within 2 to 5 min in 90—95% yields.     

Cycloaddition reaction of methyl 2-pyronecarboxylates with 1,3-dienes

The experimental results of thermal cycloaddition reactions of methyl 2-pyrone-3-, 4-, 5- and 6-carboxylates with 1,3-dienes and the theoretical approach by a second order perturbation MO method are described. The sequential introduction of a methoxycarbonyl group onto a 2-pyrone ring caused a variety of selectivities in the cycloaddition reactions with 1,3-butadienes. PMO treatment based only on the frontier molecular orbitals failed to account adequately for this selectivity phenomena because the relative magnitudes of the coefficients in the HO and LU orbitals of 2-pyrones were little affected by the introduction of a substituent. PMO treatment including superjacent and subjacent orbitais along with frontier orbitais rationalized excellently the observed selectivity phenomena.     

Tandem Diels-Alder cycloadditions of 2-pyrone-5-acrylates for the efficient synthesis of novel tetracyclolactones

Readily prepared from the regioselective Pd-catalyzed coupling reactions of 3,5-dibromo-2-pyrone, 3-bromo-2-pyrone-5-carboxylates undergo tandem uninterrupted sequential Diels-Alder cycloaddition reactions with allyl vinyl ethers in a highly regio- and stereoselective fashion to provide a series of novel tetracyclolactones in good yields.     

Fused polycyclic nitrogen-containing heterocycles: IX. Synthesis and molecular structure of methyl 3-(2-R-5-phenylthiazol-4-yl)-7-phenyl-7<Emphasis Type="Italic">H</Emphasis>-[1,2,4]triazolo-[3,4-<Emphasis Type="Italic">b</Emphasis>][1,3,4]thiadiazine-6-carboxylates

4-Amino-3-(2-R-5-phenylthiazol-4-yl)-1,2,4-triazole-5-thiones react with methyl 3-chloro-2-oxo-3-phenylpropionate to give methyl 3-(2-R-5-phenylthiazol-4-yl)-7-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-6-carboxylates. According to the X-ray diffraction data, the thiazole ring in the products is planar, while the thiadiazine ring has a distorted unsymmetrical boat conformation. Depending on the substituent in the thiazole ring, methyl 3-(2-R-5-phenylthiazol-4-yl)-7-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-6-carboxylates in crystal give rise to different supramolecular structures, lamellar and cylindrical.Translated from Zhurnal Organicheskoi Khimii, Vol. 40, No. 9, 2004, pp. 1358–1365.Original Russian Text Copyright © 2004 by Mamedov, Mustakimova, Gubaidullin, Litvinov, Levin.     

Synthesis and Primary Antitumor Screening of 4-[5-(1H-Indol-3-ylmethylidene)-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]butanamides

Russian Journal of Organic Chemistry - A preparative procedure was developed for the synthesis of 4-[5-(1-R-1H-indol-3-ylmethylidene)-4-oxo-2-sulfanylidene-1,3-thiazolidin-3-yl]butanoic acids which...     

Synthesis and Spectral,Electrochemical, and Antioxidant Properties of 2-(5-Aryl-6-R-3-phenyl-5,6-dihydro-4H-1,2,4,5-tetrazin-1-yl)-1,3-benzothiazoles

Russian Journal of Organic Chemistry - New 2-(5-aryl-6-R-3-phenyl-5,6-dihydro-4H-1,2,4,5-tetrazin-1-yl)-1,3-benzothiazoles were synthesized from the corresponding formazans by alkylation and...     

Efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates from the reaction of carbon disulfide and primary amines in the presence of diethyl 2-chloromalonate

An efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates via reaction of primary amines with CS₂ in the presence of diethyl 2-chloromalonate is described.     

Convenient selective synthesis of 5,7,8,9-tetrahydro-4H,6H-chromeno[2,3-d][1,3]oxazin-4-ones

A method for the synthesis of 5,7,8,9-tetrahydro-4H,6H-chromeno[2,3-d][1,3]oxazin-4-ones was developed. The method involves acid-catalyzed acylation of substituted ethyl 2-amino-4-aryl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylates with acetic anhydride.     

Polycondensed nitrogen heterocycles. XXII. A new synthesis of 5,6-dihydro-7H-pyrazolo[1,5-d][1,4]benzodiazepin-6-ones

A new synthesis of 2-methyl-9-R'-10-R-5,6-dihydro-7H-pyrazolo[1,5-d][1,4]benzodiazepin-6-ones ( 4a-c ) is deserved. Reaction of ethyl hydrazinoacetate hydrochloride with 1,3-diketones 1a-c gave both 3-methyl-5-(4R'-5-R-2-nitrophenyl)pyrazol-1-yl-acetate acids ( 2a-c ) and the corresponding ethyl esters 3a-c . Reduction with the appropiate reducing agent of compounds 2a-c and 3a-c directly gave the title compounds. Compound 4a showed insecticidal properties against the house fly.     

2-R-5-Ar(Het)-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones

A novel method for synthesis of 2-R-5-Ar(Het)-5,6-dihydro-7H-[1,2,4]triazolo[5,1-b][1,3]thiazin-7-ones by condensation of 3-R-4,5-dihydro-1H-1,2,4-triazole-5-thiones with 3-aryl(heteryl)-2-propenoyl chlorides is proposed.     

A Facile Synthesis of Functionalized 1,2,6,7-Tetrahydroimidazo[1,5-c]pyrimidine-3,5-diones

A Pd-mediated hydrogenation of ethyl 6-azidomethyl-1,2,3,4-tetrahydro-4-R-2-oxo-5-pyrimidinecarboxylates leads to the corresponding ethyl 6-aminomethyl1,2,3,4-tetrahydro-4-R-2-oxo-5-pyrimidinecarboxylates. The latter react with bis(trichloromethyl)carbonate, yielding the title ethyl 1,2,3,5,6,7-hexahydro-7-R-3,5-dioxoimidazo[1,5-c]pyrimidine-8-carboxylates.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Synthesis of 6-aryl- and 5-aroylcomanic acids from 5-aroyl-2-carbethoxy-4-pyrones via a deformylative rearrangement and ring-opening/ring-closure sequence

The reaction of 1-aryl-2-(dimethylaminomethylene)butane-1,3-diones with diethyl oxalate in the presence of sodium hydride in THF gave ethyl 5-aroyl-4-oxo-4H-pyran-2-carboxylates, from which 4-oxo-6-aryl-4H-pyran-2-carboxylic acids (6-arylcomanic acids) were obtained in high yields via acid-catalyzed deformylative rearrangement. 5-Aroyl-4-oxo-4H-pyran-2-carboxylic acids (5-aroylcomanic acids) were prepared via а ring-opening/ring-closure sequence by the reaction of 5-aroyl-2-carbethoxy-4-pyrones with piperidine and subsequent basic hydrolysis and acidification.     

Efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates from the reaction of carbon disulfide and primary amines in the presence of diethyl 2-chloromalonate

An efficient synthesis of ethyl 3-alkyl-4-oxo-2-thioxo-1,3-thiazolane-5-carboxylates via reaction of primary amines with CS₂ in the presence of diethyl 2-chloromalonate is described. Correspondence: Issa Yavari, Chemistry Department, Tarbiat Modares University, PO Box 14115-175, Tehran, Iran.     

Heterocyclization of functionalized heterocumulenes with C,N-, C,O, and C,S-binucleophiles: IX. Reaction of 1-aryl-1-chloro-2,2,2-trifluoroethyl isocyanates with sulfanylacetic acid esters as a convenient synthetic route to 2-aryl-2-trifluoromethyl-4-oxo-1,3-thiazolidine-5-carboxylates

1-Aryl-1-chloro-2,2,2-trifluoroethyl isocyanates reacted with methyl and ethyl sulfanylacetates to give the corresponding alkyl 2-aryl-2-trifluoromethyl-4-oxo-1,3-thiazolidine-5-carboxylates.     

A one-pot synthesis of functionalized ethyl 1,3-thiazole-5-carboxylates from thioamides or thioureas and 2-chloro-1,3-dicarbonyl compounds in an ionic liquid

Abstract  

A simple one-pot synthesis of functionalized ethyl 1,3-thiazole-5-carboxylates from the reaction of 2-chloro-1,3-dicarbonyl compounds with thioureas or thioamides in the presence of 1-butyl-3-methylimidazolium trifluoromethanesulfonate is described.     

A new selective preparation of ethyl 7-aminopteridine-6- carboxylate derivatives and related compound

A series of ethyl 7-amino-2,4-dioxopteridine-6-carboxylates 4 and ethyl 7-amino-4-oxo-2-thioxopteridine-6-carboxylates 5 , of interest biologically, has been prepared in one step from the reaction of such vicinal-diamines as 1,3-dialkyl-5,6-diaminouracils 2 or 1,3-dialkyl-5,6-diamino-2-thiouracils 3 with diethyl (E)-2,3-dicyanobutenedioate ( 1 ). Moreover, ethyl 3-amino[1,2,4]triazino[2,3-a]-1H-benzimidazole-2-carboxylate ( 11 ) was also obtained from the reaction between 1,2-diamino-1H-benzimidazole ( 10 ) and 1 . The structural studies of 4, 5 , and 11 prepared were carried out by nmr experiments in some details.     

New method for the annelation of a pyridine ring on derivatives of imidazole and benzimidazole

The interaction of (Z)-1,3-diaryl-4-bromo-2-buten-1-ones with 1-substituted (benz)imidazoles in benzene gave (Z)-1-R-3-(2,4-diaryl-4-oxo-2-butenyl)-1H-imidazolium bromides and (Z)-1-R-3-(2,4-diaryl-4-oxo-2-butenyl)-1H-benzimidazolium bromides which readily cyclize in the presence of base to form derivatives of 7,9-diarylpyrido[1,2-a]benzimidazole and 6,8-diarylpyrimidazo[1,2-a]pyridine. The effects of the nature of substituents in the benzene ring of the diarylbutenones and the substituent at N(1) in the (benz)imidazoles on the alkylation and cyclization reactions has been studied. The optimum conditions for the synthesis of the 5-R-4-hydroxy-2,4-diphenyl-4,5-dihydro-1H-pyrido[1,2-a]benz-imidazol-10-ium, 5-R-2,4-diaryl-4-hydroxy-4,5-dihydro-3H-pyrido[1,2-a]benzimidazol-10-ium, and 5-R-2,4-diaryl-5H-pyrido[1,2-a]benzimidazol-10-ium have been found.