Reactions of dimethyl and di-tert-butyl 2-aryl-4-hydroxy-4-methyl-6-oxocyclohexane-1,3-dicarboxylates with difunctional nucleophiles

The nature of the alkyl group in the ester moieties of dimethyl and di-tert-butyl 2-aryl-4-hydroxy-4-methyl-6-oxocyclohexane-1,3-dicarboxylates affects the direction of their reactions with difunctional nucleophiles. The dimethyl esters react with hydrazine hydrate to give the corresponding tetrahydroindazoles, while their tert-butyl analogs are converted under similar conditions into 6-hydrazones. Reactions of both dimethyl and di-tert-butyl 6-oxocyclohexane-1,3-dicarboxylates with hydroxylamine lead to formation of 6-hydroxyimino derivatives.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1687–1691.Original Russian Text Copyright © 2004 by V. Gein, N. Gein, Potemkin, Krivenko.This revised version was published online in April 2005 with a corrected cover date.     

Reaction of dialkyl 2-aryl-4-hydroxy-4-methyl-6-oxocyclohexane-1,3-dicarboxylates with aliphatic amines

Benzylamine, phenethylamine, and homoveratrylamine reacted with dialkyl 2-aryl-4-hydroxy-4-methyl-6-oxocyclohexane-1,3-dicarboxylates at the endocyclic carbonyl group with conservation of the enolic hydroxy group to give dialkyl 4-alkylamino-2-aryl-6-hydroxy-6-methylcyclohex-3-ene-1,3-dicarboxylates. The reaction of dimethyl 4-hydroxy-4-methyl-6-oxo-2-phenylcyclohexane-1,3-dicarboxylate with tryptamine was accompanied by dehydration with formation of dimethyl 4-[2-(1H-indol-3-yl)ethylamino]-6-methyl-2-phenylcyclohexa-3,5-diene-1,3-dicarboxylate, presumably due to basic properties of the indole nitrogen atom.     

Reaction of aromatic aldehydes with β-dicarbonyl compounds in a catalytic system: Piperidinium acetate-1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

Condensation of aromatic (heteroaromatic) aldehydes with 1,3-dicarbonyl compounds under the 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF₄]) ionic liquid-piperidinium acetate catalytic system (0.2 equiv. of each component) in the absence of a solvent affords, depending on the structures of the reagents, 2-arylidene derivatives of methyl acetoacetate and acetylacetone, diethyl 2,4-bis(trifluoroacetyl)-3-phenylpentanedioate, or dimethyl 2-aryl-4-hydroxy-6-oxocyclohexane-1,3-dicarboxylates. The reactions of the resulting 2-arylidene derivatives with O-methylisourea in the [Bmim][BF₄] ionic liquid produced methyl 2-methoxy-4-methyl-6-aryldihydropyrimidine-5-carboxylates and 1-(2-methoxy-4-methyl-6-phenyldihydropyrimidin-5-yl)ethanone (mixtures of 3,6- and 1,6-dihydro isomers), which were transformed into the corresponding 3,4-dihydropyrimidin-2(1H)-one derivatives. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1199–1204, May, 2005.     

Reactions of alkyl acetone-1,3-dicarboxylates with cyanamide and benzoylcyanamide

The reactions of cyanamide with dialkyl acetone-1,3-dicarboxylates in the presence of nickel acetylacetonate afforded alkyl 2-amino-4-hydroxy-6-oxo-1,6-dihydropyridine-3-carboxylates. The same compounds were obtained by intramolecular cyclization of adducts of acetone-1,3-dicarboxylates with benzoylcyanamide under the action of sodium alkoxides. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1304–1306, May, 2005.     

Synthesis and Biological Activity of 4-Aryl-3,6-dihydroxy-6-methyl-4,5,6,7-tetrahydro-2H-indazole-5-carboxamides

Russian Journal of General Chemistry - The reaction of 2-aryl-4-hydroxy-4-methyl-6-oxocyclohexane-1,3-dicarboxamides with hydrazine hydrate in ethanol gave...     

Study of Nitrogen- and Sulfur-Containing Heterocycles. 57. Synthesis and Conversion of 4′-Substituted 5-(5-Amino-6-Pyrimidylthio)-2,2-Dimethyl-4,6-Dioxo-1,3-Dioxanes

By reaction of 4-substituted 5-amino-6-mercaptopyrimidines with 5-bromo-2,2-dimethyl-4,6-dioxo-1,3-dioxane, we have obtained 4′-substituted 5-(5-amino-6-pyrimidylthio)-2,2-dimethyl-4,6-dioxo-1,3-dioxanes. We have studied diazotization of these compounds by isoamyl nitrite. In the case of 4′-methoxy- and 4′-dimethylamino-substituted derivatives, we have obtained derivatives of novel heterocyclic systems: pyrimido[5,4-e][1,3,4]thiadiazine and pyrimido[5,4-e][1,3,4]thiadiazine-7-spiro-5′-1,3-dioxane, and in the case of the 4′-isopropylamino-substituted derivative we obtained 4-isopropyl-7-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)-1,2,3-triazolo[5,4-d]pyrimidin-7-ylidene.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 613–623, April, 2005.     

Synthesis of 5-Hydroxy-1,3-benzoxathiol-2-one and 2-Amino-1,3-benzothiazol-6-ol Derivatives from Chrysenequinonecarboxylic Acid

Diterpenoid 5-hydroxy-1,3-benzoxathiol-2-one and 2-amino-1,3-benzothiazol-6-ol derivatives were synthesized by reaction of methyl chrysenequinonecarboxylate with thiourea.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 849–852.Original Russian Text Copyright © 2005 by Tret’yakova, Flekhter, Galin, Shul’ts, Tolstikov.     

Synthesis and structure of (thio)semicarbazonocyclohexanedicarboxylates. Crystalline and molecular structure of diethyl 4-hydroxy-4-methyl-2-phenyl-6-thiosemicarbazonocyclohexane-1,3-dicarboxylate

Diethyl 2-aryl-4-hydroxy-4-methyl-6-(thio)semicarbazonocyclohexane-1,3-dicarboxylates were synthesized, and their structure was determined by ¹H and ¹³C NMR spectroscopy, including the HSQC technique. The molecular and crystalline structure of diethyl 4-hydroxy-4-methyl-6-thiosemicarbazono-2-phenylcyclohexane-1,3-dicarboxylate was determined by X-ray analysis.     

Synthesis of 5-Alkyl(aryl)-2-alkylsulfanyl(alkoxy)-4-hydroxy-6H-1,3-oxazin-6-ones

Alkyl carbamates and S-alkyl thiocarbamates react with substituted malonyl dichlorides in boiling benzene to give the corresponding 2,5-substituted 4-hydroxy-6H-1,3-oxazin-6-ones. The reaction of S-methyl thiocarbamate with unsubstituted malonyl dichloride in boiling diethyl ether or benzene leads to formation of S-methyl (3-methylsulfanylaminocarbonyl-3-oxopropionyl)thiocarbamate and is not accompanied by cyclization, whereas in boiling toluene 4-hydroxy-2-methylsulfanyl-6H-1,3-oxazin-6-one is obtained.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 3, 2005, pp. 468–472.Original Russian Text Copyright © 2005 by Lalaev, Yakovlev, Zakhs.     

Synthesis and Biological Activity of 4,5,6,7-Tetrahydro-2H-indazole Derivatives

Russian Journal of General Chemistry - Novel 4,5,6,7-tetrahydro-2H-indazole derivatives were obtained via the reaction of N1,N3,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides with...     

Gas-Phase Reaction of Anisole and Phenol with Tetrachlorogermane in the Presence of Hexachlorodisilane

Gas-phase reaction of anisole with tetrachlorogermane in the presence of hexachlorodisilane was studied. The major reaction products are chloro(phenoxy)silane, trichloro(phenoxy)germane, 1,1,3,3-tetrachloro-1,3-disila-2-oxaindane, and 1,1,3,3-tetrachloro-1,3-digerma-2-oxaindane. The same products are formed with phenol instead of anisole. A mechanism of the reactions of anisole with GeCl₄ and Si₂Cl₆ is proposed, that takes account of the formation in the reaction zone of dichlorosilylenes and dichlorogermylenes.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 606–609.Original Russian Text Copyright © 2005 by Chernyshev, Bykovchenko, Komalenko, Yakovleva, Simakina.     

Macroheterocyclic Compounds with p-Diamines of the Diaryl Series

The reactions of indane-1,3-dione with 4,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfide, and 4,4′-diaminodiphenyl ether were used to synthesize symmetrical macroheterocyclic compounds.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 6, 2005, pp. 1017–1021.Original Russian Text Copyright © 2005 by Berezina, Vorob’ev, Vorob’eva, Sadova.     

Formation of 3-pyrrolin-2-one or imidazolidine derivatives by slow dimerization of N-substituted aziridine-2-carboxylates

Prolonged storage (45–60 days) of N-methyl- or N-cyclopropylaziridine-2-carboxylates leads to their dimerization through the N—C(3) bond cleavage to form 1,3-disubstituted 2-methylimidazolidine-2,4-dicarboxylates in high yields. Prolonged storage of 1-benzyl-aziridine-2-carboxylate (like the reactions of alkyl pyruvates with primary amines) results in cyclocondensation to yield 3-pyrrolin-2-one derivative. Dedicated to Corresponding Member of the Russian Academy of Sciences E. P. Serebryakov on the occasion of his 70th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 1025–1029, April, 2005.     

The molecular diversity of three-component reactions of 4-dimethylamino- or 4-methoxypyridine with acetylenedicarboxylates and arylidene cyanoacetates

The three-component reactions of 4-dimethylamino- or 4-methoxypyridine with acetylenedicarboxylates and arylidene cyanoacetates showed very interesting molecular diversity. The polysubstituted 1,8,9,9a-tetrahydro-4H-1,4-ethanoquinolizines, 2H-pyran-2,3-dicarboxylates, and buta-1,3-diene-1,2,4-tricarboxylates derivatives can be formed in high yields and with good diastereoselectivity depending on the substrates and reaction conditions.     

Synthesis of 1,3,4-Oxadiazinium Bromides from 1,1-Dimethylhydrazine Derivatives and 1,3-Dibromopropyne

2-Aryl(heteryl, dimethylamino)-6-bromomethylidene-4,4-dimethyl-5H-1,3,4-oxadiazinium bromides were prepared in good yields by the reactions of 1-aroyl(heteroyl)-2,2-dimethylhydrazines and 1,1,4,4-tetramethylsemicarbazide with 1,3-dibromopropyne in MeOH or MeCN at 20–50°C.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 3, 2005, pp. 473–475.Original Russian Text Copyright © 2005 by Nakhmanovich, Elokhina, Larina, Abramova, Lopyrev.     

Baeyer–Villiger oxidation of <Emphasis Type="Italic">N</Emphasis> <Superscript>1</Superscript>,<Emphasis Type="Italic">N</Emphasis> <Superscript>3</Superscript>,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides

Baeyer–Villiger oxidation of N¹,N³,2-triaryl-6-hydroxy-6-methyl-4-oxocyclohexane-1,3-dicarboxamides with 30% hydrogen peroxide in acetic acid afforded 2-(4-aryl-3-carbamoyl-2-methyl-5-oxooxolan-2-yl)acetic acids.     

Hydrosilylation reactions of hydrosilatrane and 2-methyl-6-ethyl-1,3-dioxa-6-aza-2-silacyclooctane

Conclusions 1-Hydrosilatrane does not react with monosubstituted ethylenes (or acetylenes) either in the presence of platinum or rhodium complexes or upon initiation of the reactions using organic peroxides, UV irradiation, or thermal methods. By contrast, 2-methyl-6-ethyl-1,3-dioxa-6-aza-2-silacyclooctane readily takes part in hydrosilylation of the indicated unsaturated compounds when Rhacac (CO)₂ is present.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khirnicheskaya, No. 4, pp. 899–901, April, 1986.     

Synthesis of oxoindolin-3-ylidene-1,3-dithioles

An efficient and one-pot synthesis of 2-(2-oxoindolin-3-ylidene)-1,3-dithiole-4,5-dicarboxylates by a three-component condensation reaction of isatins, carbon disulfide and dialkyl acetylendicarboxylates in the presence of Bu₃P is reported. Reaction of carbon disulfide and dialkyl acetylene dicarboxylates with acenaphthylene-1,2-dione, ninhydrine and pyrimidine-tetraone resulted in the formation of 2-(2-oxoacenaphthylen-1(2H)-ylidene)-1,3-dithiole-4,5-dicarboxylates, 2-(1,3-dioxo-1H-inden-2(3H)-ylidene)-1,3-dithiole-4,5-dicarboxylates and 2-(2,4,6-trioxotetrahydropyrimidin-5(6H)-ylidene)-1,3-dithiole-4,5-dicarboxylates, respectively, in the same conditions.     

Crystal structure of diethyl-1-isobutyl-9-hydroxy-9-methyl-7-phenyl-1,4-diazaspiro[4,5] decane-6,8-dicarboxylate C25H38N2O5

The reaction of diethyl-4-hydroxy-4-methyl-2-phenyl-6-oxocyclohexane-1,3-dicarboxylate with Nisobutylethylenediamine is performed and the crystal structure of this reaction product (diethyl-1-isobutyl-9-hydroxy-9-methyl-7-phenyl-1,4-diazaspiro[4,5]decane-6,8-dicarboxylate) is determined by X-ray crystallography.     

A novel attractive interaction in the Diels–Alder reaction of N-protected pyrroles with allene-1,3-dicarboxylates

The endo/exo selectivities of Diels–Alder reactions of N-protected pyrroles with allene-1,3-dicarboxylates were studied under Lewis acid assisted and thermal reaction conditions. A novel attractive effect between the N-protective carbonyl group of pyrrole and the ester group of allene-1,3-dicarboxylates operates to control the selectivity in the above Diels–Alder reaction. This new attractive effect to give the exo adduct is more effective than the Alder orbital effect.