A one-step synthesis of 2-Alkyl-5-hydroxychromones and 3-Alkoyl-2-alkyl-5-hydroxychromones

2-Alkyl-5-hydroxychromones (2-alkyl-5-hydroxy-4-oxo-4H-1-benzopyran) and 3-alkoyl-2-alkyl-5-hydroxychromones (3-alkoyl-2-alkyl-5-hydroxy-4-oxo-4H-1-benzopyran) were prepared in one-step and one pot reaction by condensation of 2',6'-dihydroxyacetophenone with an alkoyl chloride in the presence of K2CO3.     

New, diastereoselective synthesis of 1-alkyl-5-alkylidene-3-methylidenepyrrolidin-2-ones

The diastereoselective synthesis of 1-alkyl-5-alkylidene-3-methylidenepyrrolidin-2-ones was readily accomplished in a two-step reaction sequence consisting of the reaction of 2-diethoxyphosphoryl-4-oxoalkanoates with amines followed by Horner-Wadsworth-Emmons olefination of formaldehyde using the intermediate 1-alkyl-5-alkylidene-3-diethoxyphosphorylpyrrolidin-2-ones.     

An unusual synthetic way to 2-methyl-3-alkyl-6-ethoxy-heptan-2-ols from 2-ethoxy-5-alkyl-3,4-dihydro-2H-pyrans

A simple and swift preparation of 2-methyl-3-alkyl-6-ethoxyheptan-2-ols may be accomplished in two steps starting from 2-ethoxy-5-alkyl-3-,4-dihydro-2H-pyrans via chlorination of the heterocyclic compounds and subsequent reaction with MeMgBr.     

Substituted 5-aryl- or 5-diphenylmethyl-3-alkyl-2-oxazolidones as anticonvulsants

Several 5-aryl- or 5-diphenylmethylhydracrylyl hydrazides were synthesized and converted into 5-aryl- or diphenylmethyl-2-oxazolidones. The latter compounds were further alkylated into their corresponding 5-aryl- or 5-diphenylmethyl-3-alkyl-2-oxazolidones as possible anticon-vusants.     

Formylation of 5-alkyl-3H-furan-2-ones

3-Formyl derivatives of 3H-furanones and 2-chlorofurans are formed in the reaction of 5-alkyl-3H-furan-2-ones with POCl₃ and DMF. The conditions for the purposeful synthesis of these compounds were found. The transformations of the formyl group in reactions with dinitrophenylhydrazine and aniline were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 456–458, April, 1993.     

Regioselective synthesis of 1-alkyl-5-(indol-3-yl- and -2-yl)pyrrolidin-2-ones from available reagents

The reaction under mild conditions of 1-alkyl-5-hydroxypyrrolidin-2-ones with different indoles having a free 3 position leads exclusively to 1-alkyl-5-(indol-3-yl)pyrrolidin-2-ones but if position 3 is occupied to 1-alkyl-5-(indol-2-yl)pyrrolidin-2-ones.     

Phase-transfer catalysis in reactions of 5-alkyl-3H-furan-2-ones with dichlorocarbene

Treatment of 5-alkyl-3H-furan-2-ones and 5-alkyl-3H-thiophen-2-ones with dichlorocarbene under conditions of phase-transfer catalysis at 20–90 °C results in insertion of the carbene at the C=C bond followed by skeletal rearrangement.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1995–1997, October, 1995.     

Regioselective alkylation of 2-alkyl-5,6,7,8-tetrahydro-3h-cycloheptimidazol-4-ones and 2-alkyl-3h-cycloheptimidazol-4-ones

Regioselective alkylation of 2-alkyl-5,6,7,8-tetrahydro-3H-cycloheptimidazol-4-one (1) and 2-alkyl-3H-cycloheptimidazol-4-one (2) was investigated. 3-[2'-(1-tert-Butyl-1H-tetrazol-5-yl)biphenyl-4-ylmethyl]-2-propyl-5,6,7,8-tetrahydro-1H-cycloheptimidazol-4-one (6) was preferentially obtained under the conditions by using NaH in DMF or THF. On the other hand, 3-[2'-(1-tert-butyl-1H-tetrazol-5-yl)biphenyl-4-ylmethyl]-2-propyl-5,6,7,8-tetrahydro-3H-cycloheptimidazol-4-one (5), the synthetic intermediate compound of Pratosartan, was obtained selectively in the presence of n-Bu(4)NBr in toluene by using aqueous sodium hydroxide as a base. In this reaction, it was found that the concentration of the alkaline solution influences its regioselectivity. This selectivity was observed even for aldehyde and ester derivatives.     

A convenient synthesis of 3-alkyl-2,3-dihydro-2,4-dioxo-6-phenyl-, 3-alkyl-2,3-dihydro-4-oxo-6-phenyl-2-thioxo-, and 3-alkyl-2-arylimino-2,3-dihydro-4-oxo-6-phenyl-4H-1,3-thiazines

The reactions of 1-alkylamino-1-alkylthio-3-phenylpropene-3-thiones 3 with thiophosgene and phosgene in toluene, followed by treatment of the reaction mixture with triethylamine gave 3-alkyl-2,3-dihydro-4-oxo-6-phenyl-2-thioxo- 4 , 3-alkyl-2,3-dihydro-2,4-dioxo-6-phenyl-4H-1,3-thiazines 5 , respectively in good to excellent yields. Similarly treatment of compounds 3 with N-arylimidoyl dichloride in benzene at room temperature gave 3-alkyl-2-arylimino-2,3-dihydro-4-oxo-6-phenyl-4H-1,3-thiazines 6 in excellent yields. The reactions of compounds 3 with oxalyl chloride in toluene gave also 5 in good yields.     

Reactivities of 5-alkyl-2-thioxopyrrolidines

The chemical transformations of 5-alkyl-2-thioxopyrrolidines with nucleophilic and electrophilic reagents were studied and compared with the reactivities of their oxygen analogs. On the basis of the experimental data obtained from alkylation, hydroxyethylation, and condensation reactions it was established that, depending on the conditions and the character of the reagent, 5-alkyl-2-thioxopyrrolidines undergo the indicated reactions in the thiolactam or thiolactin form.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1648–1651, December, 1979Original article submitted November 25, 1978.     

The Synthesis of 2-Alkylthio-3-alkyl-5-arylmethylidene4H-imidazol-4-ones

2-alkylthio-3-alkyl-5-arylmethylidene-4H-imidazol-4-ones were synthesized by the S-alkylation and N-alkylation of 2-thioxo-5-arylmethylidene-4-imidazolidinones, which were obtained via a tandem aza-Wittig reaction of vinyliminophosphoranes, carbon disulfide, and excess ammonium hydroxide (28% NH₃ in water).     

A novel conversion of acetylenic 1,2,4-triazoles into 3-alkyl-5-arylpyridazines

Bromination of 2-aryl-1-[1,2,4]triazol-1-ylalk-3-yn-2-ols gives 6-bromo-7-hydroxy-5-alkyl-7-aryl-7,8-dihydro-[1,2,4]triazolo[1,2-a]pyridazin-4-ylium salts, which are converted by treatment with strong alkali into novel 3-alkyl-5-arylpyridazines.     

Synthesis of mesomorphic 2-alkyl-5-(p-cyanophenyl)pyridines

A new series of liquid-crystal derivatives of 2-alkyl-5-(p-cyanophenyl)pyridines were obtained by halogenation of 2-alkyl-5-phenylpyridines under the conditions of the Birckenbach-Gubo-Waters reaction with subsequent conversion of the 2-alkyl-5-(p-bromo- or iodophenyl) pyridines to the cyano derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 85–88, January, 1981.     

Synthesis of new 1,2,4-oxadiazolidin-3-ones by cycloaddition of 2-alkyl-3-aryloxaziridines with chlorosulfonylisocyanate

2-Alkyl-4-chlorosulfonyl-5-aryl-1,2,4-oxadiazolidin-3-ones 5 were prepared via cycloaddition of 2-alkyl-3-aryloxaziridines 3 with chlorosulfonylisocyanate. The structure of 5 was proved by a crystal X-ray analysis. Hydrolysis of 5 in the presence of triethylamine afforded 2-alkyl-5-aryl-1,2,4-oxadiazolidin-3-ones 6.     

Regioselective synthesis of 4-(2-alkyl-5-methyl-2H-pyrazol-3-yl)-piperidines

The regioselective, scaleable synthesis of three 4-(2-alkyl-5-methyl-2H-pyrazol-3-yl)-piperidines is discussed.     

Synthesis of 4-methyl-5-alkyl-2-imidazolinones

Conclusions 4-Methyl-5-alkyl-2-imidazolinones were synthesized by heating 3-halo-2-alkanones with a mixture of piperidine, N,N-diethylacetamide, urea, zinc chloride and magnesium carbonate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1887–1890, August, 1987.     

Highly effective stereoselective synthesis of vinyl ethers of 5-alkyl-2-(2-furyl)-5-hydroxymethyl-1,3-dioxanes

The vinylation of cis-5-alkyl-5-hydroxymethyl-2-(2-furyl)-1,3-dioxanes in the KOH–DMSO system in acetylene at atmospheric or elevated pressures (85-100°C, 3 h) takes place stereoselectively and leads to the formation of cis-5-alkyl-2-(2-furyl)-5-vinyloxymethyl-1,3-dioxanes with yields of up to 93%.     

Recyclization of ethyl 1-alkyl-5-benzoyl-6-methylsulfanyl-2-oxo-1,2-dihydropyridine-3-carboxylates into Bicyclic <Emphasis Type="Italic">N</Emphasis>-alkyl-5-benzoyl-2-oxo-1,2-dihydropyridine-3-carboxamide derivatives by the action of nitrogen-containing 1,4- and 1,5-binucleophiles

Reactions of ethyl 1-alkyl-5-benzoyl-6-methylsulfanyl-2-oxo-1,2-dihydropyridine-3-carboxylates with nitrogen-containing 1,4- and 1,5-binucleophiles (o-phenylenediamine, o-aminobenzenethiol, ethane-1,2-diamine, and propane-1,3-diamine) involved recyclization, leading to the formation of fused N-alkyl-5-benzoyl- 2-oxo-1,2-dihydropyridine-3-carboxamides, diethyl 6,6′-oxybis(1-alkyl-5-benzoyl-2-oxo-1,2-dihydropyridine-3-carboxylates), and diethyl 6,6′-[ethane-1,2-diyl(or propane-1,3-diyl)diimino]bis(1-alkyl-5-benzoyl-2-oxo-1,2-dihydropyridine-3-carboxylates), depending on the reactant ratio. The sequence of formation of intermediate recyclization products was determined.     

Recyclization of 1-alkyl-5-benzoyl-3-ethoxycarbonyl-6-methylthio-1,2-dihydro-pyridin-2-ones into 1,6-annelated derivatives of 3-alkylcarbamoyl-5-benzoylpyridin-2-one

For the first time the possibility has been shown of recyclizing 1-alkyl-5-benzoyl-3-ethoxycarbonyl-6-methylthio-1,2-dihydropyridin-2-ones into 1,6-annelated bicyclic derivatives of 3-alkylcarbamoyl-5-benzoylpyridin-2-one, which takes place on reacting the former with 1,4- and 1,5-nitrogen-containing dinucleophiles. The structure of the recyclization products was demonstrated by spectral methods and X-ray structural analysis.     

Synthesis of 3-alkyl-5-hydroxycyclohex-2-enones via aldolic addition/sulfinate elimination tandem reactions

The first synthesis of 3-alkyl-5-hydroxycyclohex-2-enones is reported. An intramolecular cyclization by means of an aldolic addition/sulfinate elimination tandem reactions, performed under mild basic conditions was the key step.