Synthesis of azepino[1,2-<Emphasis Type="Italic">a</Emphasis>]benzimidazoles and imidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]azepines

Fusion of 4-bromo-1,3-diphenyl-2-buten-1-ones (γ-bromodypnones) with 1,2-dimethyl-1H-benzimidazole and further treatment of the reaction product with a base (morpholine) gives 7,9-diaryl-5-methyl5,10-dihydroazepino[1,2-a]benzimidazol-11-ium bromides. The reaction of γ-bromodypnone with 1-alkyl-2-methyl-1H-imidazoles in benzene at 25 °C gives quaternary azolium salts. Upon heating their solutions in alcohol in the presence of K₂CO₃ the latter cyclize to 1-R-6,8-diaryl-1,5-dihydroimidazo[1,2-a]azepin-4-ium bromides or 1-R-6,8-diaryl-1H-imidazo[1,2-a]azepines depending on the nature of the substituent in the benzene rings and the substituent at the N(1) atom of the imidazole.     

Synthesis of 2,4-diphenyl-1H-pyrrol-1-amine derivatives

The direction of the reaction of 4-bromo-1,3-diphenyl-2-buten-1-one (γ-bromodypnone) with hydrazines depends on the nature of the substituent they contain. Reaction with 1-methylhydrazinium hydrosulfate gives 1-methyl-3,5-diphenylpyridazin-1-ium bromide but carboxylic acid hydrazides give N-(2,4-diphenyl-1H-pyrrol-1-yl)carboxylic acid amides. γ-Bromodypnone and phenylhydrazine give both 1,3,5-triphenyl-1,4-dihydropyridazine and N,2,4-triphenyl-1H-pyrrol-1-amine (15%). 1-(2,4-Dinitrophenyl)hydrazine gives the 2,4-dinitrophenylhydrazone of (Z)-4-bromo-1,3-diphenyl-2-buten-1-one. Condensation of 2,4-diphenyl-1H-pyrrol-1-amine with aromatic aldehydes readily leads to N-(arylmethylidene)-2,4-diphenyl-1H-pyrrol-1-amines and alkylation with methyl iodide gives N,N-dimethyl-2,4-diphenyl-1H-pyrrol-1-amine. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 404–414, March, 2009.     

Studies on Pyrimidines: Synthesis of Pyrimidine-Annelated Heterocycles from 5-Amino-6-cyclohex-2-enyl-1, 3-dimethyl-uracil

Summary.  Treatment of 5-amino-6-cyclohex-2-enyl-1, 3-dimethyl-uracil with pyridinium hydrotribromide or hexamethylenetetrammonium hydrotribromide furnished the corresponding linear heterocyclic 6-bromo-1, 3-dimethylhexahydroindolo[3,2-d]pyrimidine-2, 4-diones in 90% yield. Reaction of the same educt with molecular bromine in chloroform afforded the bicyclic 9-bromo-1, 3-dimethylhexahydrobicyclo[3.3.1]indolo[3,2-d]pyrimidine-2, 4-diones in 85% yield. Upon treatment of the above substrate with cold concentrated sulfuric acid, a mixture of 1, 3-dimethylhexahydro-indolo[3, 2-d]pyrimidine-2, 4-dione (28%) and 1, 3-dimethylhexahydrobicyclo[3.3.1]indolo[3, 2-d]pyrimidine-2, 4-dione (60%) was obtained. Received August 4, 2000. Accepted (revised) November 15, 2000     

Bromination-Dehydrobromination of 4-Aryl-5-nitro-6-phenyl-3,4-dihydropyrimidin-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

Depending on the conditions, bromination of 4-aryl-5-nitro-6-phenyl-3,4-dihydropyrimidine-2(1H)-ones and subsequent dehydrobromination gives either 4-aryl-5-nitro-6-phenylpyrimidin-2(1H)-ones or their mixtures with the corresponding 4-aryl-5-bromo-6-methoxy-5-nitro-6-phenyltetrahydropyrimidin-2-ones which are formed as two diastereoisomers.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 425–430.Original Russian Text Copyright © 2005 by Sedova, Gatilov, Shkurko.     

Steroidal imidazopyridines and lactam imidazopyridines

Condensation of 17β-acetoxy-2α-bromo-5α-androstan-3-one with unsubstituted and substituted amino-pyridines, gives the corresponding 17β-acetoxy-5α-androstanimidazo[1,2-a]pyridines. Treatment of 16α-bromo-3-aza-A-homo-4α-androsten-4,17-dione with 2-aminopyridine or methyl-2-aminopyridine produces the corresponding 3-aza-A-homo-4α-androsten[16,17:2′,3′]imidazo[1,2-a]pyridines. Similarly, from 2α-bromo-17β-acetamido-5α-androstan-3-one and methylaminopyridine the 17β-acetamido-5α-androstan[2,3:2′,3′]imidazo[1,2-a]methylpyridine has been obtained. The structure of the compounds was apparent from their chemical properties and spectral data (ir, uv and nmr).     

A reaction of 6-bromo-1,2-naphthoquinone with tri(<Emphasis Type="Italic">n</Emphasis>-butyl)phosphine: A convenient route to phosphorus-containing 1,2-naphthoquinones and 1,2-dihydroxynaphthalenes

A reaction of 6-bromo-1,2-naphthoquinone with tri(n-butyl)phosphine gave 2-hydroxy-4-tri(n-butyl)phosphonionaphth-1-olate (betaine with the P—C bond). When treated with bromine, this betaine changed into (6-bromo-1,2-dihydroxy-4-naphthyl)tri(n-butyl)phosphonium bromide and (6-bromo-1,2-dioxo-1,2-dihydro-4-naphthyl)tri(n-butyl)phosphonium bromide in the ratio ∼1: 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 534–536, March, 2007.     

Synthesis and antimicrobial activity of imidazo- and pyrimido[2,1-f]-theophyllines

Heating of 8-aminotheophylline with methyl (Z)-2-benzoylamino-3-(dimethylamino)propenoate in acetic acid afforded in a one-pot synthesis a new pyrimido[2,1-f]theophylline derivative. Methylation of this by using CH₃I/NaH furnished in good yield the double methylated derivative. Furthermore, glycosidation of the former with 1-α-bromo-2,3,4,6-tetra-O-acetyl-d-glucose gave the β-glucoside derivative. Reaction of 8-aminotheophylline with [bis(methylthio)methylene]malonitrile, ethyl[bis(methylthio)methylene]cyanoacetate, 1,3-diphenylprop-2-en-1-one, 2-cyano-1,3-diphenylprop-2-en-1-one, 1-(4-nitrophenyl)-3-(dimethylamino)prop-2-ennitrile, 1-phenyl-3-(dimethylamino)prop-2-en-1-one, 2-substituted 3-aryl or heteroarylprop-2-ennitrile and ethyl(arylmethylene)cyanoacetate in N,N-dimethylformamide in the presence of anhydrous potassium carbonate afforded also the corresponding new derivatives of pyrimido-[2,1-f]theophylline. However, 8-aminotheophylline reacted in similar manner with 3-chloropentan-2,4-dione and 2-bromo-1-phenylethanone to give the corresponding imidazo[2,1-f]theophyllines. Furthermore, azo-coupling of one of these with 4-methylphenyldiazonium chloride was performed. The antimicrobial activity of the products has been evaluated. The structures of all new compounds obtained were established by their spectral analyses. Correspondence: Mosselhi A. N. Mosselhi, Department of Chemistry, Faculty of Science, Cairo University, Cairo, Egypt.     

Regioselective synthesis of 1-aryl-4-bromo-5-trifluoromethylpyrazoles

A novel regioselective route to 1-aryl-4-bromo-5-trifluoromethylpyrazoles involves reactions of arylhydrazines with 3-bromo-4-ethoxy-1,1,1-trifluorobut-3-en-2-one. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 167–168, January, 2006.     

Synthesis and structure of 3-arylidene and 3-hetarylidene-1,2-dihydro-3H-1,4-benzodiazepin-2-ones and their affinity toward CNS benzodiazepine receptors

The condensation of 5-aryl-7-bromo-1,2-dihydro-3H-1,4-benzodiazepin-2-ones with aromatic aldehydes gives 5-aryl-3-arylidene-and 5-aryl-7-bromo-3-hetarylidene-1,2-dihydro-3H-1,4-benzodiazepin-2-ones. X-ray diffraction structural analysis yielded the molecular and crystal structures of 7-bromo-3-(4′-methoxybenzylidene)-5-phenyl-1,2-dihydro-3H-1,4-diazepin-2-one and showed that this compound has cis configuration. Radioligand analysis was used to study the affinity of these products toward central nervous system and peripheral benzodiazepine receptors. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1213–1225, August, 2007.     

Condensation of γ-bromodypnone with thiocarbamides: Synthesis of 4,4-disubstituted 4,5-dihydro-1,3-thiazol-2-amines and thiazolidin-2-ones

The reaction of 4-bromo-1,3-diphenyl-2-buten-1-one with thiourea or N,N′-diphenylthiourea gives 2-(2-amino-4-phenyl-4,5-dihydro-1,3-thiazol-4-yl)-and 2-[3,4-diphenyl-2-(phenylimino)-1,3-thiazolidin-4-yl]-1-phenyl-1-ethanone — the products of nucleophilic substitution of the halogen atom and Michael addition at position 3 of the 2-buten-1-one system. A similar reaction with thiosemicarbazide and 1-phenylthiosemicarbazide gives the 4-(2-oxo-2-phenylethyl)-4-phenyl-and 4-(2-oxo-2-phenylethyl)-3,4-diphenyl-1,3-thiazolidin-2-one hydrobromides respectively. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 103–110, January, 2008.     

Reactions of spirocyclopropane-containing 1- and 2-pyrazolines with electrophilic reagents

Hydrochlorination of spiro(1-pyrazoline-3,1′-cyclopropanes) proceeds regioselectively at the azocyclopropane group to form 3-(2-haloethyl)pyrazoline derivatives. If the latter contain a halogen atom in the heterocycle, they are readily converted into (2-haloethyl)pyrazole hydrohalides. Bromination of 3-cyanospiro(2-pyrazoline-5,1′-cyclopropane) withN-bromosuccinimide at 20°C proceeds with retention of the cyclopropane ring to form 3-bromo-3-cyanospiro(1-pyrazoline-5,1′-cyclopropane), which is converted into (2-bromoethyl)cyanopyrazole in ∼60% yield at ∼20°C after 3–4 days.     

Synthesis of 1,2-bis[2-methyl-5(3,4-difluorophenyl)-3-thienyl] perfluorocyclopentene

2-Methylthiophene (1) was treated at 0°C with liquid bromine to form 3,5-dibromo-2-methylthiophene (2) which reacted with tributyl borate to give 2-methyl-3-bromo-5-boronate thiophene (3) at −78°C. Treatment of 3 with 3,4-difluorobrombenzene gave 2-methyl-3-bromo-5-(3,4-difluorophenyl)thiophene (4). Finally, a novel photochromic dithienylethene compound, 1,2-bis [2-methyl-5(3,4-difluorophenyl)-3-thienyl]perfluorocyclopentene (DT-1), was synthesized by the reaction of 4 with perfluorocyclopentene at −78°C. The compound (DT-1) was characterized by IR, NMR, MS, elemental analysis and its photochromic behavior was also discussed. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(10): 1282–1284 [译自: 有机化学]     

Regioselective bromination of quinopimaric acid derivatives

Regioselective bromination of 14β-hydroxydihydroquinopimaric acid methyl ester in acetic acid and methanol gave the corresponding 16S-bromo-, 19R-bromo-, and 16S,19R-dibromo-14β,20-epoxy derivatives whose structure was determined by X-ray analysis and NMR spectroscopy. The reactions of 16S-bromo ketones with thiourea afforded 2,1,3-thiadiazoles fused to diterpene fragment.     

Synthesis in the phenothiazine series

The corresponding amines were obtained by reduction of 1-nitro-3-bromophenothiazine and 2-bromo-4-nitrophenothiazine. 1-Amino-3-bromophenothiazine reacts with formic acid to give 4-bromoimidazo[4,5,1-k, l ]phenothiazine and with carbon disulfide to give 4-bromo-1,2-dihydroimidazo [4,5,1-k, l ]phenothiazine-1-thione. 4-Aminophenothiazine reacts with sulfur and carbon disulfide to give 2, 3-dihydrothiazolo[5,4-c]phenothiazine-2-thione.See [1] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 202–203, February, 1974.     

Reactions of <Emphasis Type="Italic">N</Emphasis>-and <Emphasis Type="Italic">C</Emphasis>-Alkenylanilines: VII. Synthesis of Indole Heterocycles from Products of Reaction between <Emphasis Type="Italic">N</Emphasis>-Mesyl-2-(1-alken-1-yl)anilines and Halogens

N-Mesyl-2-(1-methyl-1-butenyl)-6-methylaniline reacted with Br₂ to afford N-mesyl-2-(3-bromo-1-penten-2-yl)aniline that under treatment with NH₃ or amines underwent cyclization into N-mesyl-7-methyl-3-methylene-2-ethylindoline. The reaction of N-mesyl-2-(1-methyl-1-buten-1-yl)-4-methyl- and 2-(1-methyl-1-buten-1-yl)aniline with Br₂ gave rise to the corresponding N-mesyl-2-(2-bromo-1-methyl-1-buten-1-yl)anilines. Under the similar conditions N-tosyl-2-(1-cyclohexen-1-yl)aniline was converted into N-tosyl-2-(6-bromo-1-cyclohexen-1-yl)aniline that under treatment with NH₃ furnished N-tosyl-1,2,3,9a-tetrahydrocarbazole. The reaction of N-mesyl-1,2,3,9a-tetrahydrocarbazole with CuBr₂ in MeOH afforded N-mesyl-4-methoxy-1,2,3,4-tetrahydrocarbazole. N-Mesyl-6-methyl-2-(1-cyclopenten-1-yl)aniline in reaction with Br₂ in the presence of NaHCO₃ was oxidized into the corresponding cyclopentenone, and with NBS it gave N-mesyl-2-(2-bromo-1-cyclopenten-1-yl)aniline.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 5, 2005, pp. 730–737.Original Russian Text Copyright © 2005 by Gataullin, Sotnikov, Spirikhin, Abdrakhmanov.     

Synthesis ofN-substituted 4-benzoyl-2-iminothiazolium bromides

Substituted thioureas react with 1-bromo-2-benzoylacetylene in various solvents at 20°C to give the correspondingN-substituted 4-benzoyl-2-(R-imino)-3-R′-thiazolium bromides. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 199–200, January, 1997.     

Reinvestigation of the synthesis of 5-arylamino-2-picolines

Reaction of 5-bromo- or 3-bromo-2-methylpyridine with o-nitroaniline gave the corresponding N-[2-methyl-5(or 3)pyridyl]-o-nitroanilines. Reduction to the corresponding amino derivatives and ring closure to 1-[2-methyl-5(or 3)pyridyl]benzotriazole allowed the structures to be confirmed and an earlier literature report to be corrected. Displacement of bromide by anthranilic acid from 5-bromo-2-methylpyridine and decarboxylation gave N-(2-methyl-5-pyridyl)aniline.     

Imidazolyl derivatives of the thiochroman ring

The synthesis of 2-(1H-imidazol-1-yl)-4H-1-benzothiopyran- 4 -ones 3 from 3-bromo-4H-1-benzothiopyran-4-ones 1 and imidazole is described. The reaction of 1 with secondary amines gives the corresponding 3 -amino-thiochromones 11. Compounds 3 can be oxidized to the sulfones 4 from which the thiochromanols 5 and thiochromene 7 can be easily obtained. 3-Bromo-2,3-dihydro-6-methyl-4H-1-benzothiopyran-4-one 12 and imidazole led by dehydrohalogenation to thiochromone, while the ketal 13 rearranged to benzo[b]thiophene 16.     

Synthesis of 5-bromo-4-dibromoamino-3-phenylisothiazole and its light-induced conversion into 3,7-diphenylbisisothiazolo[4,5-b:4′,5′-e]pyrazine

When irradiated with UV light, 5-bromo-4-dibromoamino-3-phenylisothiazole is converted into 3,7-diphenylbisisothiazolo[4,5-b:4′,5′-e]pyrazine andN,N′-bis(5-bromo-3-phenylisothiazol-4-yl)diazene. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 957–959, May, 2000.     

Reactions of 3-isopropenyltropolones with bromine and N-bromosuccinimide: Formation of 8H-cyclohepta[b]furan-8-one derivatives

3-Isopropenyltropolones 1a-c were treated with bromine in carbon tetrachloride to give 3-methyl-8H-cyclohepta[b]furan-8-ones 2a-c and their corresponding 7-bromo-substituted compounds 3a-c , while reactions in acetic acid gave the bromo-substituted compounds 3a-c . On the other hand, bromination of 1a-c with N-bromosuccinimide afforded 7-bromo-3-(2-bromo-1-methylethenyl)tropolones 5a-c . The compound 2a was treated with bromine to give 2-bromo-3-methyl-8H-cyclohepta[b]furan-8-one ( 4 ). The tropolones 5a-c were heated in the presence of potassium carbonate to give the cyclized compounds 3a-c .