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.     

Diastereoselective cyclization in chiral diarylethene crystals: polymorphism and selectivity

[structure: see text] An optically active photochromic diarylethene, (S)-1-(2-methyl-5-phenyl-3-thienyl)-2-[2-methyl-5-(4-(3-methyl-1-penten-1-yl)phenyl)-3-thienyl]perfluorocyclopentene ((S)-1a), was synthesized. (S)-1a formed two crystalline phases, alpha- and beta-phases. The diarylethene underwent a photochromic reaction in solution and even in the single-crystalline phase. In solution, no diastereoselection was observed. On the other hand, in the beta-crystalline phase, only one diastereomer (S,R,R)-1b was produced. No such diastereoselection was observed in the alpha-crystalline phase.     

Benzo-1,2,3,4-tetrazine 1,3-dioxides annulated with tetraazapentalene systems

Thermolysis of 7-azido-6-(2H-1,2,3-triazol-2-yl)-1,2,3,4-benzotetrazine 1,3-dioxide and 7-azido-6-(1H-1,2,3-triazol-1-yl)-1,2,3,4-benzotetrazine 1,3-dioxide gives rise to the new heterocyclic systems: 6,10-dehydro-6H,10H-[1,2,3]triazolo[1′,2′:2,3][1,2,3]triazolo[4,5-g]-[1,2,3,4]benzotetrazine 2,4-dioxide and 6,8-dehydro-6H,8H-[1,2,3]triazolo[1′,2′:1,2][1,2,3]-triazolo[4,5-g][1,2,3,4]benzotetrazine 2,4-dioxide, respectively, their thermal stability and spectral properties have been studied.     

Synthesis of Optically Active endo,endo Bicyclo[2.2.2]octane-2,5-diol, Bicyclo[2.2.2]octane-2,5-dione, and Related Compounds

Optically active C(2)-symmetric (1S,2S,4S,5S)-bicyclo[2.2.2]octane-2,5-diol ((+)-12; 98% ee) and several selectively protected optically active intermediates useful for synthetic transformations were synthesized via a 1,2-carbonyl transposition route starting from the easily available optically active (1R,4S,6S)-6-hydroxybicyclo[2.2.2]octan-2-one ((-)-2). The synthetic route also allowed the preparation of optically active (1S,4S)-bicyclo[2.2.2]octane-2,5-dione ((+)-14; 98% ee).     

Spirocyclohexadienones: XIII. Reactions of schiff bases with enamines derived from 3,4-dihydroisoquinoline and with spiro[naphthalene-1,3′-pyrrol]-4-one

Addition of 1,3,3-trimethyl-3,4-dihydroisoquinolines to N-benzylideneanilines gives substituted N-[2-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)-1-phenylethyl]anilines, whereas 2′,5′,5′-trimethyl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-one reacts with N-benzylideneanilines along two pathways involving cyclization to substituted 2,3,3a,4,10,11-hexahydrobenzo[f]pyrrolo[2,3-d]quinolin-5(1H)-ones or elimination of the aniline residue with formation of substituted 5′,5′-trimethyl-2-styryl-4′,5′-dihydro-4H-spiro[naphthalene-1,3′-pyrrol]-4-ones.     

Reactions of 2-phenyl-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-benzodioxaphosphepin-5-one with phenanthrenequinone and dibenzoyl

Reactions of 2-phenyl-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-benzodioxaphosphepin-5-one with 9,10-phenanthrenequinone and dibenzoyl gave hydrolytically unstable spirophosphoranes with five- and seven-membered rings, 2-phenyl-4,4-bis(trifluoromethyl)-4,5-dihydrospiro[[1,3,2]benzodioxaphosphepine-2,2′-phenanthro[9,10-d][1,3,2]dioxaphosphol]-5-one and 2,4′,5′-triphenyl-4,4-bis(trifluoromethyl)-4,5-dihydrospiro[[1,3,2]benzodioxaphosphepine-2,2′-[1,3,2]dioxaphosphol]-5-one. The structure of the first of these was proved by X-ray analysis.     

Reactions of bromine-containing organozinc compounds derived from α,α-dibromo ketones with 2-arylmethylideneindan-1,3-diones and 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones

Bromine-containing organozinc compounds generated from 1,1-dibromo-3,3-dimethylbutan-2-one reacted with 2-arylmethylideneindan-1,3-diones and 5-arylmethylidene-2,2-dimethyl-1,3-dioxane-4,6-diones to give 3-aryl-2-(2,2-dimethylpropanoyl)spiro[cyclopropane-1,2′-indan]-1′,3′-diones and 1-aryl-6,6-dimethyl-2-(2,2-dimethylpropanoyl)-5,7-dioxaspiro[2.5]octan-4,8-diones, respectively. Reactions of 2-arylmethylideneindan-1,3-diones with bromine-containing zinc enolates derived from 1-aryl-2,2-dibromopropan-1-ones and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one resulted in the formation of 2-aroyl-3-aryl-2-methylspiro-[cyclopropane-1,2′-indan]-1′,3′-diones and 2,3: 8,9-dibenzo-12-phenyldispiro[4.0.5.1]dodecane-1,4,7-trione, respectively.     

Design,synthesis and in vitro evaluation of tetrahydropyrimidine-isatin hybrids as potential antitubercular and antimalarial agents

A series of 5-substituted-3-[{5-(6-methyl-2-oxo/thioxo-4-phenyl-1,2,3,4-tetrahydropyrimidin-5-yl)-1,3,4-oxadiazol-2-yl}-imino] -1,3-dihydro-2H-indol-2-one were synthesized,characterized and screened for their anti-tubercular and antimalarial activity.     

Transformations of 3-formylindoles under the action of acids

Under the influence of acids 3-formylindole forms urorosein (the salt of di(indol-3-yl)methylium) which is unstable in solution and decomposes to give a series of indole derivatives, among which 6-(indol-3-yl)-5H,7H-indolo[2,3-b]carbazole and tri(indol-3-yl)methylium salt predominate. N,N′-Dimethylurorosein in solution also forms a mixture of indole derivatives, from which tri(1-methylindol-3-yl)methylium salt, 5N,11N-dimethylindolo[3,2-b]carbazole and its 6-(1-methylindol-3-yl) derivative were isolated. Research Institute of New Antibiotics, RAMN (Russian Academy of Medical Science), Moscow 119867, Russia; Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 631–639, May, 1999.     

Efficient synthesis of (-)-gamma-lycorane alkaloid by two Bu3SnH-mediated radical cyclisations

An asymmetric induction using (S)-1-arylethylamine-based chiral auxiliary and two Bu(3)SnH-mediated radical cyclisations have been developed for a total synthesis of (-)-gamma-lycorane (1). The first cyclisation proceeded in 5-endo-trig manner with moderate diastereoselectivtiy to give (3aR,7aR)-octahydroindol-2-one 6b as the major product using alpha-iodo-N-(6-oxocyclohexen-1-yl)-N-[(S)-1-phenylethyl] acetamide (5b). In the second cyclisation, the radical precursor 8 was used as substrate to construct the optically active lycorane skeleton 15 which was reduced using LiAlH4 into (-)-gamma-lycorane (1).     

Synthesis and alkylation of n<Subscript>(3)</Subscript>-aryl-n<Subscript>(5)</Subscript>-phenyl-6-amino-4-aryl(2-furyl)-2-thioxo-1,2,3,4-tetrahydropyridine-3,5-dicarboxamide

N₍₃₎-Aryl-N₍₅₎-phenyl-6-amino-4-aryl(2-furyl)-2-thioxo-1,2,3,4-tetrahydropyridine-3,5-dicarboxamides have been obtained by the interaction of N-phenyl-3-aryl(2-furyl)-2-cyanoacrylamides with 3-amino-3-thioxopropananilides under the conditions of the Michael reaction. N₍₃₎-Aryl-N₍₅₎-phenyl-2-alkylthio-6-amino-4-aryl(2-furyl)-3,4-dihydropyridine-3,5-dicarboxamides and N₍₃₎, N₍₅₎-diphenyl-6-benzylthio-4-(2-furyl)-2-oxo-1,2,3,4-tetrahydropyridine-3,5-dicarboxamides were synthesized by alkylation of the products. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1018–1023, July, 2008.     

The practical synthesis of a uterine relaxant, bis(2-[[(2S)-2-([(2R)-2-hydroxy-2-[4-hydroxy-3-(2-hydroxyethyl)-phenyl]ethyl]amino)-1,2,3,4-tetrahydronaphthalen-7-yl]oxy]-N,N-dimethylacetamide) sulfate (KUR-1246)

The synthetic route for a uterine relaxant, bis(2-[[(2S)-2-([(2R)-2-hydroxy-2-[4-hydroxy-3-(2-hydroxyethyl)-phenyl]ethyl]amino)-1,2,3,4-tetrahydronaphthalen-7-yl]oxy]-N,N-dimethylacetamide) sulfate (KUR-1246), was established by the coupling of optically active components, the bromohydrin 14 and the amine 24. We now describe the practical synthesis of these two optically active components. Bromohydrin 14 was obtained by the asymmetric borane reduction of the prochiral phenacyl bromide 13 using a catalyst prepared from aluminum triethoxide and a chiral amino alcohol. The other optically active component 24 was prepared from (S)-AMT.     

Synthesis of 7-(2-R-pyrimidin-4-yl)- and 7-(2-R-[1,2,4]triazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]pyrimidin-7-yl)-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinolines

Cyclization of 3-(dimethylamino)-1-(2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinolin-7-yl)prop-2-en-1-one with carboximidamides, guanidines, and 1,2,4-triazol-5-amines afforded a number of new 2,2,4,6-tetramethyl-7-(2-R-pyrimidin-4-yl)-1,2,3,4-tetrahydroquinolines and 2,2,4,6-tetramethyl-7-(2-R-[1,2,4]triazolo-[1,5-a]pyrimidin-7-yl)-1,2,3,4-tetrahydroquinolines.     

Derivatives of α,β-dehydroamino acids: V. Intramolecular cyclization of 2-{2-[(<Emphasis Type="Italic">Z</Emphasis>)-1-Benzamido-2-phenylvinyl]acetamidomethyl}benzimidazole

Reaction of 4-benzylidene-2-phenyl-1,3-oxazol-5(4H)-one with 2-(1H-benzimidazol-2-yl)ethaneamine led to the formation of 2-{2-[(Z)-1-benzamido-2-phenylvinyl]acetamidomethyl}benzimidazole that in a reaction with hexamethyldisilazane in DMF gave 5-benzylidene-1-(1H-benzimidazol-2-yl)-2-phenyl-3,5-dihydro-4H-imidazol-4-one. In the presence of K₂CO₃ in dioxane the reaction with hexamethyldisilazane resulted in the product of intramolecular addition, N-(4-benzyl-3-oxo-1,2,3,4-tetrahydropyrazino[1,2-a]-benzimidazol-4-yl)benzamide     

Phosphotungstic acid mediated,microwave assisted solvent-free green synthesis of highly functionalized 2ˈ-spiro and 2, 3-dihydro quinazolinone and 2-methylamino benzamide derivatives from aryl and heteroaryl 2-amino amides

Phosphotungstic acid has been found as green catalyst for the synthesis of spiro and cyclized quinazolinones and 2-amino substituted carboxamide under microwave irradiation and solvent-free condition has been developed. The scope of the reaction has been demonstrated for a variety of aldehydes and ketones with O-amino amides such as 2-amino-benzamide, 2-amino-5-iodo benzamide, 3-aminothiophene-2-carboxamide, 3-aminobenzofuran-2-carboxamide and 2-aminopyridine-3-carboxamides. The reaction afforded spiro-, cyclized quinazolinones and 2-amino substituted carboxamide derivatives within few minutes of irradiation in excellent yield. Plausible mechanism for the formation of products is provided. Synthetic utility of 1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one 3a has been demonstrated by synthesis of 1,4-di(1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one) buta-1,3-diyne 12, 1′-((1-benzyl-1H-1,2,3-triazol-4-yl) methyl)-1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one 13 and 1′-phenyl-1′H-spiro[fluorene-9,2′-quinazolin]-4′(3′H)-one 14 under standard protocols.     

Synthesis,characterization, and antioxidant activity of heterocyclic Schiff bases

Schiff base derivatives have gained great importance due to revealing a great number of biological properties. Schiff bases were synthesized by treatment of 4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one ( 1 ) with various aldehydes in methanol at reflux. In addition, diamine was reacted with an aldehyde to yield the corresponding Schiff bases. The structures of synthesized Schiff bases were elucidated by spectroscopic methods such as microanalysis, ¹H-NMR, ¹³C-NMR, and FTIR. Antioxidant activities of synthesized Schiff bases were carried out using different antioxidant assays such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH^•) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power activity. (E)-4-((1H-indol-3-yl)methyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one ( 3 ), (E)-1,5-dimethyl-4-((2-methyl-1H-indol-3-yl)methyleneamino)-2-phenyl-1H-pyrazol-3(2H)-one ( 5 ), (E)-1,5-dimethyl-2-phenyl-4-(thiophen-2-ylmethyleneamino)-1H-pyrazol-3(2H)-one ( 7 ), (E)-1,5-dimethyl-2-phenyl-4-(quinolin-2-ylmethyleneamino)-1H-pyrazol-3(2H)-one ( 9 ), (1S,2S,N1,N2)-N1,N2-bis((1H-indol-3-yl)methylene)cyclohexane-1,2-diamine ( 11 ), and (1S,2S,N1,N2)-N1,N2-bis((2-methyl-1H-indol-3-yl)methylene)cyclohexane-1,2-diamine ( 12 ) were synthesized in high yields. Compound 5 displayed a good ABTS^•+ activity. Compound 3 revealed the outstanding activity in all assays. Compound 7 has the best-reducing power ability in comparison to other synthesized compounds. Although compounds 5, 11, 12 are new, compounds 3, 7, 9 are known. Due to revealing a good antioxidant activity, the synthesized compounds ( 3, 5, 7 ) have the potential to be used as synthetic antioxidant agents.     

Synthesis of 1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-c]pyridin-5-ones. I. 3-unsubstituted compounds

Synthesis of 1,2,3,4-tetrahydro-5H-[1]benzopyrano[3,4-c]pyridin-5-ones via a Pechmann condensation of 3-carbethoxy-1-methyl-4-piperidone with various phenols is described. The limitations of this method are discussed. Synthesis of the parent ring system 3a via reduction of 1,2,3,4-tetrahydro-3-(phenylmethyl)-8-[(1-phenyl-1H-tetrazol-5-yl)oxy]-5H-[1]benzopyrano[3,4-c]pyridin-5-one ( 5 ) is also described.     

5-phenyl-2H-tetrazol-2-ylmethyl ketones in the synthesis of tetrazolylalkanols and tetrazolyl(hydroxy)alkylphosphonates

The reduction of 1-(5-phenyl-2H-tetrazol-2-yl)propan-2-one and 1-phenyl-2-(5-phenyl-2H-tetrazol-2-yl)ethanone with sodium tetrahydridoborate gave 1-(5-phenyl-2H-tetrazol-2-yl)propan-1-ol and 1-phenyl-2-(5-phenyl-2H-tetrazol-2-yl)ethanol, respectively. Only 1-(5-phenyl-2H-tetrazol-2-yl)propan-2-one was reduced with baker’s yeast with an appreciable yield. 1-(5-Phenyl-2H-tetrazol-2-yl)propan-2-one and 1-phenyl-2-(5-phenyl-2H-tetrazol-2-yl)ethanone reacted with diethyl phosphonate in the presence of potassium fluoride to produce the corresponding diethyl [hydroxy(5-phenyl-2H-tetrazol-2-yl)alkyl]phosphonates.     

Structures and photochromic properties of fulgides based on naphtho[1,2-<Emphasis Type="Italic">b</Emphasis>]furan and benzo[<Emphasis Type="Italic">g</Emphasis>]indole

The novel heterocyclic fulgides, i.e. 3-isopropylidene-4-{1-[5-methoxy-1-(4-methoxy-phenyl)-2-methyl-1H-benzo[g]indol-3-yl]ethylidene}dihydrofuran-2,5-dione and 3-isopropylidene-4-[1-(1-benzyl-5-methoxy-2-methyl-1H-benzo[g]indol-3-yl)ethylidene]dihydrofuran-2,5-dione, were prepared and isolated as E-isomers. Photochromism, E-configuration, and high resistance to photocoloration—photobleaching of solutions of these fulgides as well as 3-isopropylidene-4-[1-(5-methoxy-2-methylnaphtho[1,2-b]furan-3-yl)ethylidene]dihydro-furan-2,5-dione and 3-isopropylidene-4-[1-(5-methoxy-2-methyl-1-phenyl-1H-benzo[g]indol-3-yl)ethylidene]dihydrofuran-2,5-dione synthesized previously were shown by X-ray diffraction analysis, ¹H NMR spectroscopy and electronic absorption spectroscopy. The novel fulgides show fluorescence and high thermal stability of photogenerated cyclic form. Repeated photo-coloration—photobleaching is accompanied by reversible photoinduced E—Z isomerization. Benzo[g]indolyl fulgides are characterized by the longer wavelength absorption of both original (E) and photoisomeric cyclic (C) forms as compared to naphthofuran fulgide.     

Synthesis, properties, and structures of ammonium 4-aryl-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates

The reaction of arylcyanomethylenethiocetamides with Meldrum, acid gave Michael adducts as ammonium salts. When heated in alcohol, these salts undergo cyclization to ammonium 4-aryl-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates. The structure ofN-methylmorpholinium 4-(2′-chlorophenyl)-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolate was established by X-ray structural analysis. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1029–1034, May, 1997.