Investigations in the imidazole series LXXIII. Synthesis of pyrrolo[1,2-a]benzimidazole derivatives from 2-alkyl(aralkyl)benzimidazoles

The synthesis of 2-alkyl(aryl)- and 2-aryl-3-alkyl(aryl)-4-acylmethyl-substituted pyrrolo-[1,2-a]benzimidazoles was accomplished by the reaction of 2-alkyl(aralkyl)benzimidazoles with -haloketones and subsequent cyclization of the resulting 1,3-(diacylmethyl)-2-alkyl-(aralkyl)benzimidazolium halides.See [1] for communication LXXII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 403–404, March, 1972.     

Efficient synthesis of new 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrol-2(5H)-ones

The synthesis of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrol-2(5H)-ones 5, 6a-d from 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d is reported. The 1-alkyl(aryl)-4-bromo-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 3, 4a-d were obtained from regiospecific bromination of 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones 1, 2a-d with molecular bromine. The NMR and X-ray diffraction data showed that 1-alkyl(aryl)-5-(3,3,3-trihalo-2-oxopropylidene)-1H-pyrrolidin-2-ones were brominated at 4-position in the pyrrolidin-2-one ring.     

Amidrazones. 6 . Synthesis of 1,2,4-thiadiazoles by thermolysis of N3-thiocarbamoylamidrazone ylides

Reaction of N³-unsubstituted amidrazone ylides ( 1a and 1b ) with alkyl or aryl isothiocyanates gives N³-thiocarbamoylamidrazone ylides ( 2 ). Thermolysis of 2 gives 3-alkyl(or aryl)-5-alkyl(or aryl)amino-1,2,4-thiadiazoles ( 3a-i ).     

Reactivity of 5-<Emphasis Type="Italic">endo</Emphasis>-hydroxy-4-azatricyclo[5.2.1.0<Superscript>2,6</Superscript>]dec-8-en-3-ones and their isomerization initiated by acids and bases

Study of isomerization of 5-endo-hydroxy-4-azatricyclo[5.2.1.0^2,6]dec-8-en-3-ones under the action of Lewis acids (MgBr₂, AlCl₃), CF₃COOH, and NaH showed that the optimum catalyst of the process was trifluoroacetic acid. In reaction of 4-benzyl-5-endo-hydroxy-4-azatricyclo-[5.2.1.0^2,6]dec-8-en-3-one with anhydrous AlCl₃ in benzene was unexpectedly isolated N-benzyl-3-(diphenylmethyl)bicyclo[2.2.1]hept-5-ene-2-carboxamide. A convenient method was developed for the preparation of 5-exo-alkoxy-4-alkyl(aryl)-4-azatricyclo[5.2.1.0^2,6]dec- 8-en-3-ones.     

Multicomponent Synthesis of 4-Alkyl(Aryl,Hetaryl)-2-alkoxycarbonyl(aroyl,carbamoyl)- 3,6-diamino-5-cyanothieno[2,3-<Emphasis Type="Italic">b</Emphasis>]pyridines

The condensation of malononitrile with hydrogen sulfide and aldehydes in the presence of triethylamine in ethanol at room temperature afforded 4-alkyl(aryl, hetaryl)-2,6-diamino-3,5-dicyano-4H-thiopyrans. Treatment of the latter in situ with alkali in DMF, followed by addition of an alkylating agent, led to the formation of 4-alkyl(aryl, hetaryl)-2-alkoxycarbonyl(aroyl, carbamoyl)-3,6-diamino-5-cyanothieno[2,3-b]- pyridines.     

Novel route of the reaction of trifluoromethyl-containing N-methyl(4-ethoxyphenyl)imidazolidin-2-ones with urea

The reactions of perfluorobiacetyl with N-(4-ethoxyphenyl)- and N-methylurea afforded cis- and trans-isomers of 1-methyl-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one and 1-(4-ethoxyphenyl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-one in a yield of ～60—75%. N-Alkyl(aryl)bis(trifluoromethyl)imidazooxazoles were obtained as unexpected products in the reaction of 1-alkyl(aryl)-4,5-dihydroxy-4,5-bis(trifluoromethyl)imidazolidin-2-ones with urea in dimethylacetamide. The reaction is accompanied by the rearrangement of imidazolidin-2-ones to N-alkyl(aryl)-5,5-bis(trifluoromethyl)hydantoins with CF₃ group migration from position 5 to position 4 of the starting heterocycle. A similar rearrangement is observed on boiling of the studied imidazolidin-2-ones in dimethylacetamide. The molecular structures of 3-(4-ethoxyphenyl)-5,5-bis(trifluoromethyl)imidazolidine-2,4-dione and 6-(4-ethoxyphenyl)-3a,6a-bis(trifluoromethyl)tetrahydroimidazo[4,5-d]oxazole-2,5-dione were studied by X-ray diffraction analysis.     

Synthesis of new polyfunctional 5,6,7,8-tetrahydroimidazo-[1,5-<Emphasis Type="Italic">c</Emphasis>]pyrimidin-5-ones by the aza-Wittig reaction followed by intramolecular cyclization and 1,3-prototropic shift

Ethyl 2-oxo-6-[(triphenyl-λ⁵-phosphanylidene)aminomethyl]-1,2,3,4-tetrahydropyrimidine-5-carboxylates reacted with organic isocyanates according to the aza-Wittig pattern, and the subsequent intramolecular ring closure and 1,3-H shift resulted in the formation of ethyl 3-alkyl(aryl)amino-5-oxo-5,6,7,8-tetrahydroimidazo[1,5-c]pyrimidine-8-carboxylates.     

Synthesis and structure of derivatives of azadithiapentaleneanthrone and isothiazoleanthrone

The reaction of N,N-dialkyl- or N,N-diaryl-1,5-diaminoanthrones with sulfur in a polar aprotic solvent in the presence of a base leads to the formation of 4-alkyl(aryl)amino-9-alky(aryl)-5H-anthra[1,9,8-bcde]-9-aza-1,10⁴-di-thiapentalen-5-ones. The reaction of the 1,5-diaminoanthrone, followed by methylation, leads to 7-amino-10-methylthio- and 7-amino-8,10-dimethylthio-6H-anthra[9,1-cd]isothiazol-6-ones. The structures of the last two compounds and of 4-methylamino-9-methylazadithiapentaleneanthrone were studied by x-ray crystallography. Elimination of the amino group occurs in each series. The structural features and the spectral characteristics of the new heterocyclic systems are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 417–425, March, 1990.     

Investigations in the region of 2,3′-biquinoline. 3. Synthesis of 2′-alkyl(aryl)-1′,2′-dihydro-2,3′-biquinolines and 2′-alkyl(aryl)-2,3′-biquinolines

A method was developed for the synthesis of 2-alkyl(aryl)-1,2-dihydro-2,3-biquinolines, based on the addition of organolithium compounds to 2,3-biquinoline in the presence of tetramethylethylenediamine. Their oxidation with manganese dioxide led to 2-alkyl(aryl)-2,3-biquinolines.For Communication 2, see [1].Stavropol State University, Stavropol 355009, Russia. Russian Chemical-Technology University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–354, March, 1998.     

Condensation of fluoroalkyl-containing 1,2,3-trione 2-arylhydrazones with methylamine

Fluoroalkyl-containing 1,2,3-trione 2-arylhydrazones react with methylamine in different ways, depending on the substrate structure. Arylhydrazones having a short fluoroalkyl substituent (R_F = CF₃, HCF₂CF₂) react at the carbonyl group adjacent to the nonfluorinated substituent to give 3-alkyl(aryl)-2-aryldiazenyl-3-methylamino-1-polyfluoroalkylprop-2-en-1-ones. Arylhydrazones with a long-chain fluoroalkyl group (R_F = C₃F₇ and longer) and a bulky nonfluorinated group take up methylamine molecule at the carbonyl group linked to the fluorinated substituent, and the subsequent haloform reaction yields N-methyl-2-arylhydrazono-3-oxobutanamides. Both types of products are formed in reactions of methylamine with 1,2,3-triketone 2-arylhydrazones having a long fluoroalkyl group and methyl group at the other carbonyl group. Template condensation of fluoroalkyl-containing 1,2,3-trione 2-arylhydrazones with methylamine over Ni(II) template gives bis[3-alkyl(aryl)-1-polyfluoroalkyl-3-methylamino-2-aryldiazenylprop-2-en-1-onato-N,N′]-nickel(II), regardless of the size of the fluoroalkyl substituent. The same complexes and their copper analogs can be obtained by treatment of 3-alkyl(aryl)-2-aryldiazenyl-3-methylamino-1-polyfluoroalkylprop-2-en-1-ones with the corresponding metal salts.     

Features of reaction of substituted 4-oxobutanoic acids and 3<Emphasis Type="Italic">H</Emphasis>-furan-2-ones with 1,3-binucleophiles

Differences were found in reactions of 4-alkyl(aryl)-substituted 4-oxobutanoic acids and 3H-furan-2-ones with 1,3-binucleophiles, 2-(aminomethyl)aniline and 2-(aminophenyl)methanol. Depending on initial substrates different fused tricyclic systems are formed.     

Synthesis and Molecular and Crystalline Structure of Polyfluoro-1,3-Diazafluorenes

Reactions of 2-amino-3-(1-imino-2,2,2-trifluoroethyl)hexafluoro-1H-indene with carboxylic acid anhydrides and chlorides afforded 2-alkyl(aryl)-4-trifluoromethyl-5,6,7,8,9,9-hexafluoro-1,3-diazafluorenes. The molecular and crystalline structure of the products was studied by NMR spectroscopy and X-ray diffraction. 5,6,7,8,9,9-Hexafluoro-2-phenyl-4-trifluoromethyl-1,3-diazafluorene in crystal gives rise to infinite ladder chains via -stacking interaction between the benzene ring of one molecule and tetrafluorobenzene fragment of the other.     

Synthesis of formyl-thienylpyrroles: versatile building blocks for NLO materials

Several formyl-substituted 1-alkyl(aryl)-2-(2′-thienyl)pyrroles 3-7 were synthesized by functionalization of the pyrrole or thiophene ring of thienylpyrroles 2 using different methods: Vilsmeier formylation or metalation followed by reaction with DMF.     

Synthesis of 3-alkyl-1,4-dihydrocyclopenta[b]indoles: unexpected formation of dimeric compounds

Acid-catalyzed dehydration of 3-alkyl(aryl)-4-methyl-1,2,3,4-tetrahydrocyclopenta[b]indol-3-ols gives dimeric derivatives of 3-alkyl(aryl)-4-methyl-1,4-dihydrocyclopenta[b]indole.     

Novel synthesis of monofluorocyclobutanes by the ring expansion- fluorination of cyclopropylmethanols with an amine-metal fluoride pyridinium poly(hydrogen fluoride)-complex

Various new 1-fluoro-1-alkyl(or aryl)-2-substituted cyclobutanes were synthesized stereoselectively from 1-alkyl(or aryl)cyclopropyl carbinols by the ring expansion-fluorination using (ⁱPr)₂-KHF₂-(HF)_n·Py, and 2-hydroxymethyl-1-fluorocyclobutanes were synthesized via a new rearrangement of (1-alkyl(or aryl)cyclopropyl) ethylene oxides.     

Reaction of 3-oxodihydrothionaphthenes with aryl diazonium chlorides and aryl isothiocyanates

The reaction of 3-oxodihydrothionaphthenes with aryl diazonium chlorides gives 2-arylhydrazono-3-oxodihydrothionaphthenes. By oxidation of the latter with hydrogen peroxide in glacial acetic add, new 2-arylhydrazonodihydrothionaphthene-(3)-one-1, 1-dioxides are synthesized. Condensation of aryl isothiocyanates with 3-oxodihydrothionaphthenes in tetrahydrofuran gives 2-(arylthiocarbamyl)-3-oxodihydrothionaphthenes; cyclization of the latter with -bromoacetophene leads to the synthesis of 4-phenyl-3-aryl-2-(3 -oxodihydrothionaphthylidene-2)-⁴-thiazolines.     

1-alkyl 3,5-diallyl isocyanurates as synthetic building blocks for sulfur-containing macroheterocycles

2-Sulfanylethanol was added to readily available 1-alkyl 3,5-diallyl isocyanurates to obtain 1-alkyl 3,5-bis[3-(2-hydroxyethylsulfanyl)propyl] isocyanurates. Treatment of the products with thionyl chloride gave 1-alkyl 3,5-bis[3-(2-chloroethylsulfanyl)propyl] isocyanurates whose reaction with thiourea followed by hydrolysis resulted in preparation 1-alkyl 3,5-bis[3-(2-sulfanylethylsulfanyl)propyl] isocyanurates. Oxiative cyclization of the latter gave macrocyclic disulfides in 56–75% yields. The composition and structure of the macrocyclic disulfides were established on the basis of the elemental and X-ray diffraction analyses, ¹H and ¹³C NMR and IR spectra, as well as MALDI-TOF and electron impact mass spectra.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1368–1376.Original Russian Text Copyright © 2004 by Fattakhov, Shulaeva, Saifina, Efremov, Rizvanov, Soloveva, Nafikova, Azancheev, Gubaidullin, Litvinov, Reznik.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of 9-Substituted 2-Alkyl(aryl)imidazo-[1,2-<Emphasis Type="Italic">a</Emphasis>]benzimidazole-3-carbonitriles

A one-pot preparative synthesis of 9-substituted 2-alkyl(aryl)imidazo[1,2-a]benzimidazole-3-carbonitriles from the corresponding 3-carbaldehydes and hydroxylamine O-sulfonic acid has been developed.     

Reaction of 3‐aminoquinoline‐2,4‐diones with isocyanates. Synthesis of novel 3‐(3′‐alkyl/arylureido)quinoline‐2,4‐diones and their cyclic carbinolamide isomers

3‐Alkyl/aryl‐3‐amino‐1H,3H‐quinoline‐2,4‐diones react with alkyl/aryl isocyanates to give novel 3‐alkyl/aryl‐3‐ureido‐1H,3H‐quinoline‐2,4‐diones or 3a‐alkyl/aryl‐9b‐hydroxy‐3,3a,5,9b‐tetrahydro‐1H‐imidazo[4,5‐c]quinoline‐2,4‐diones. In some cases, a mixture of both products was obtained and separated by fractional crystallization. All compounds were characterized by their ¹H, ¹³C, ir and ms data and some of them also by ¹⁵N nmr data.