Electrophilic heterocyclization of 6-alken(yn)ylsulfanyl-pyrazolo[3,4-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4(5<Emphasis Type="Italic">H</Emphasis>)-ones

6-Allylsulfanyl-1-arylpyrazolo[3,4-d]pyrimidin-4(5H)-ones react with iodine and sulfuric acid to give angular pyrazolothiazolopyrimidine derivatives. The reaction of 6-(prop-2-yn-1-ylsulfanyl)-1-(4-tolyl)-pyrazolo[3,4-d]pyrimidin-4(5H)-one with sulfuric acid gives angularly fused pyrazolo[4,3-e][1,3]thiazolo-[3,2-a]pyrimidin-4-one, whereas in the reaction with sodium methoxide linearly fused pyrazolo[3,4-d][1,3]-thiazolo[3,2-a]pyrimidin-4-one was formed. Linearly fused pyrazolo[3′,4′:4,5]pyrimido[2,1-b][1,3]thiazole derivatives were also obtained by reaction of 1-aryl-6-(3-phenylprop-2-en-1-ylsulfanyl)pyrazolo[3,4-d]pyrimidin-4(5H)-ones with sulfuric acid.     

Synthesis of 1-(1,3-dialkyl-2-oxo-2,3-dihydro-1<Emphasis Type="Italic">H</Emphasis>-imidazo-[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acids

Nitration of 2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-one gave its 5-nitro derivative which was subjected to alkylation with dimethyl sulfate, diethyl sulfate, and benzyl(dimethyl)phenylammonium chloride. The resulting 1,3-dimethyl-, 1,3-diethyl-, and 1,3-dibenzyl-5-nitro-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones were reduced to the corresponding 1,3-dialkyl-5-amino-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones, and the latter reacted with itaconic acid to produce 1-(1,3-dialkyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acids. 1-(2-Oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-5-oxopyrrolidine-3-carboxylic acid was obtained by analogous reaction with 5-amino-2,3-dihydro-1H-imidazo[4,5-b]-pyridin-2-one.     

Nitration of 1,3-dihydro-2<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-2-one derivatives

Nitration of 1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one and its N-methyl derivatives at 0–5°C and 60°C gives 5-nitro-and 5,6-dinitro-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones, respectively. The latter can also be obtained by nitration of 5-mononitro derivatives under similar conditions. The nitration of 6-chloro-and 6-bromo-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones and their N-methyl-substituted analogs leads to the formation of the corresponding 6-chloro(bromo)-5-nitro compounds. The same products are formed in the nitration of 5,6-dichloro-and 5,6-dibromo-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones. In this case, the process involves replacement of the halogen atom in position 5 of the pyridine fragment by nitro group. The nitration of 6-bromo-5-methyl-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-one is accompanied by oxidation of the 5-methyl group to carboxy.     

Reactions of 1,3-Dialkyl-5-amino-1,3-dihydro-2<Emphasis Type="Italic">H</Emphasis>-imidazo-[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridin-2-ones with acetylacetone and ethyl acetoacetate

1,3-Dialkyl-5-amino-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones reacted with acetylacetone to give the corresponding 4-(1,3-dialkyl-2-oxo-1,3-dihydro-2H-imidazo[4,5-b]pyridin-5-ylamino)pent-3-en-2-ones which underwent intramolecular cyclization to 1,3-dialkyl-5,7-dimethyl-1,3-dihydro-2H-imidazo[4,5-b]-[1,8]naphthyridin-2-ones on heating in polyphosphoric acid or diphenyl ether. Analogous reaction of 1,3-dialkyl-5-amino-1,3-dihydro-2H-imidazo[4,5-b]pyridin-2-ones with ethyl acetoacetate led to the formation of ethyl 3-(1,3-dialkyl-2-oxo-1,3-dihydro-2H-imidazo[4,5-b]pyridin-5-ylamino)but-2-enoates whose cyclization afforded 1,3-dialkyl-8-hydroxy-7-methyl-1,3-dihydro-2H-imidazo[5,4-b][1,8]naphthyridin-2-ones.     

Synthesis and antimicrobial activity of novel fused [1,2,4]triazino[5,6-<Emphasis Type="Italic">b</Emphasis>]indole derivatives

Synthesis of new fused systems of triazino[5,6-b]indole starting with preparation of 3-amino[1,2,4]-triazino[5,6-b]indole 1 by reaction of isatin with 2-aminoguanidinium carbonate in boiling acetic acid is presented [1]. Intermediate compound 1 reacted with aldehyde, ethyl chloroformate, triethyl orthoformate, and ninhydrine and gave new heterotetracyclic nitrogen systems, such as 3-(N ²-guanidinylimino)indole-2(1H)-one 2, 3-(N-ethoxycarbonylamino)-4H-[1,2,4]triazino[5,6-b]indole 3, 3-(N-ethoxymethyleneamino)-4H-[1,2,4]-triazino[5,6-b]indole 4, 3-(hydrazinothiocarbonylamino)-4H-[1,2,4]triazino[5,6-b]indole 5, respectively. N-(1,3-dioxoindene-2-ylidene)-4H-[1,2,4]triazino[5,6-b]indol-3-amine 6 was synthesized by reaction of compound 1 with aldehyde, ethyl chloroformate, triethyl orthoformate, and ninhydrine. New fused indole systems, pyrimido[2′,1′:3,4][1,2,4]triazino[5,6-b]indol-3(4H)-one 8, 9, 11, 12 and 1H-imidazo[2′,1′:3,4][1,2,4]triazino-[5,6-b]indol-2(3H)-one 10, were synthesized in the reaction of the intermediate 1 with bifunctional compounds. Structures of the products were elucidated from their elemental analysis and spectral data (IR, ¹H and ¹³C NMR and mass spectra). Antimicrobial activity of some synthesized compounds was tested.     

Reaction of hexahydropyirimidine-2,4,6-trione with naphthalen-2-amine and benzaldehydes

Previously unknown 12-aryl-7,8,9,10,11,12-hexahydrobenzo[f]pyrimido[4,5-b]quinoline-9,11-diones were synthesized by three-component condensation of naphthalen-2-amine with substituted benzaldehydes and barbituric acid through intermediate 5-benzylidenebarbituric acids.     

Synthesis of New Heterocyclic Systems on the Basis of 7-Benzyl-3-chloro-1-(morpholin-4-yl)-5,6,7,8-tetrahydro-2,7-naphthiridine-4-carbonitrile

Methods have been developed for the synthesis of new 8-amino-3-benzyl-5-(morpholin-4-yl)-1,2,3,4-tetrahydropyrimido[4′,5′: 4,5]thieno[2,3-c][2,7]naphthyridine starting from 7-benzyl-3-chloro-1-(morpholin-4-yl)-5,6,7,8-tetrahydro-2,7-naphthyridine-4-carbonitrile. 8-Hydrazinyl-3-benzyl-5-(morpholin-4-yl)-1,2,3,4-tetrahydropyrimido[4′,5′: 4,5]thieno[2,3-c][2,7]naphthyridine has been converted to isomeric pentacyclic structures with a triazole ring fused through the [c] side of the pyrimidine ring, and their Dimroth rearrangement has been accomplished in both acidic and basic media. New heterocyclic systems containing pyrrolo[1,2-a]pyrimidinone and pyrimido[1,2-a]azepinone fragments were obtained on the basis of the thieno-[2,3-c][2,7]naphthyridine derivative.     

Synthesis of arylmethylpyrimidinetriones and pyrimidoquinolinediones with fluorescent and nonlinear-optical properties

5-Arylmethyl-2,4,6-(1H,3H,5H)pyrimidinetriones and 12-aryl-8,12-dihydrobenzo[f]pyrimido[4,5-b]quinoline-9,11-(7H,10H)diones were synthesized, and their spectral-luminescence and nonlinear-optical properties were examined.     

Recyclization of 1,3-dialkyl-6-nitro-1<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridine-2,5(3<Emphasis Type="Italic">H</Emphasis>,4<Emphasis Type="Italic">H</Emphasis>)-diones into imidazole derivatives

Treatment of 5-amino-1,3-dialkyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones with sodium nitrite in aqueous HCl gave 1,3-dialkyl-1H-imidazo[4,5-b]pyridine-2,5(3H,4H)-diones which were nitrated with potassium nitrate in sulfuric acid to 6-nitro derivatives, and the latter underwent recyclization into 4-amino-1,3-dialkyl-5-(1H-pyrazol-5-yl)-2,3-dihydro-1H-imidazol-2-ones by the action of hydrazine hydrate.     

Synthesis of 4-alkyl(aryl,hetaryl)-2-thioxo-5,6,7,8-tetrahydroquinoline-3-carbonitriles and their derivatives by cross-recyclization of 4-alkyl(aryl,hetaryl)-2,6-diamino-4<Emphasis Type="Italic">H</Emphasis>-thiopyran-3,5-dicarbonitriles with 4-(cyclohex-1-en-1-yl)-morpholine,alkyl halides,and cyclohexanone

Cross recyclization of 4-substituted 2,6-diamino-4H-thiopyran-3,5-dicarbonitriles with 4-(cyclohex-1-en-1-yl)morpholine, alkyl halides, and cyclohexanone gave the corresponding substituted 2-thioxo-1,2,5,6,7,8-hexahydroquinoline-3-carbonitriles, 2-alkylsulfanyl-5,6,7,8-tetrahydroquinoline-3-carbonitriles, 3-amino-5,6,7,8-tetrahydrothieno[2,3-b]quinoline-2-carboxamides, and 4-oxo-2,2-pentamethylene-1,2,3,4,7,8,9,10-octahydropyrimido[4′,5′:4,5]thieno[2,3-b]quinolines. The structure of 3-(4-bromophenyl)-2,2-pentamethylene-11-(2-thienyl)-1,2,3,4,7,8,9,10-octahydropyrimido[4′,5′:4,5]thieno[2,3-b]quinoline was proved by X-ray analysis.     

Synthesis and Antimycobacterial Activity of Hydrazides Based on Pyridoxine Derivatives

Pyridoxine derivatives, 3-hydroxy-2-methylpyridine-4- and -5-carbohydrazides, were synthesized according to optimized known procedures, and a method for the synthesis of 5-(hydroxymethyl)-2,2,8-trimethyl-4H-[1,3]dioxino[4,5-c]pyridine-6-carbohydrazide was developed. The hydroxymethyl groups in positions 5 and 6 of 2,2,8-trimethyl-4H-[1,3]dioxino[4,5-c]pyridine showed different reactivities, and only the 6-hydroxymethyl group was selectively oxidized to aldehyde under mild conditions. The lactone ring in 5,6-dihydrofuro[3,4-b]pyridin-7(5H)-one was found to be stable to nucleophiles. The synthesized hydrazides showed no antimycobacterial activity.     

Thermolysis of 1-(methylideneamino)-1<Emphasis Type="Italic">H</Emphasis>-pyrrole-2,3-diones. Synthesis of pyrazolooxazines by [4 + 2]-cycloaddition of azomethine imines to alkenes

Thermolysis of methyl 3-acyl-1-[(diphenylmethylidene)amino]-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates generates 4-acyl-1-(diphenylmethylidene)-3-(methoxycarbonyl)-1H-pyrazol-1-ium-5-olates which react with alkenes to give methyl 3-acyl-7,7-diphenyl-6,7-dihydro-5H-pyrazolo[5,1-b][1,3]oxazine-2- carboxylates. The product structure was confirmed by X-ray analysis.     

Reactions of 2-(2-propynylsulfanyl)-5,6,7,8-tetrahydrobenzo[<Emphasis Type="Italic">b</Emphasis>]thieno[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4(<Emphasis Type="Italic">3H</Emphasis>)-one with arylsulfenyl chlorides

2-(2-propynylsulfanyl)-5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-one with arylsulfenyl chlorides in chloroform gave products of anti-Markownikoff Ad _E-addition. The use of nitromethane as solvent in the presence of lithium perchlorate additives favored intramolecular electrophilic cyclization into 1-arylsulfanyl-1,2,6,7,8,9-hexahydro-4H-benzo[4,5]thieno[3,2-e][1,3]thiazolo[3,2-a]-pyrimidin-5-one.     

Synthesis and Structure of 4-Indolyl-5-(thieno[3,2-<Emphasis Type="Italic">b</Emphasis>]pyrrol-6-yl)imidazoles

A procedure was proposed for regioselective acylation of methyl 2-methyl-4H-thieno[3,2-b]-pyrrole-5-carboxylate with 2-(3-indolyl)-2-oxoacetyl chloride. Reactions of the resulting methyl 6-[2-(3-indolyl)-1,2-dioxoethyl]-2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate with aromatic aldehydes and ammonium acetate in acetic acid afforded the corresponding methyl 6-[2-aryl-4-(3-indolyl)imidazol-5-yl]-2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylates. The structure of methyl 6-[2-(4-chlorophenyl)-4-(3-indolyl)imidazol-5-yl]-2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate was studied by X-ray analysis.     

Synthesis and properties of cyanomethyl derivatives of imidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]pyridine,imidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]pyrimidine,and imidazo[2,1-<Emphasis Type="Italic">b</Emphasis>]thiazole

2-Cyanomethyl derivatives were obtained of imidazo[1,2-a]pyridine, imidazo[1,2-a]pyrimidine, and imidazo[2,1-b]thiazole, and their reactivity was investigated by an example of imidazo[1,2-a]pyridine: It was subjected to nitration, bromination, azo coupling and nitrosation. Acylation of the methylene group effected by amino acids esters with a subsequent addition of the amino group to the cyano group resulted in the formation of 5-amino-4-imidazo[1,2-a]-pyridin-2-yl-1-phenyl-1,2-dihydro-3H-pyrrol-3-one and 2-amino-1-ethyl-3-imidazol[1,2-a]pyridin-2-yl-4(1H)-quinolinone.     

Halocyclization of 3-{[2-methyl(bromo)prop-2-en-1-yl]-sulfanyl}-5<Emphasis Type="Italic">H</Emphasis>-[1,2,4]triazino[5,6-<Emphasis Type="Italic">b</Emphasis>]indoles

Reactions of 3-[(2-bromoprop-2-en-1-yl)sulfanyl]-5H-[1,2,4]triazino[5,6-b]indole with bromine and of 3-[(2-methylprop-2-en-1-yl)sulfanyl]-5H-[1,2,4]triazino[5,6-b]indole with iodine and bromine afforded 3-halomethyl-10H-[1,3]thiazolo[3′,2′: 2,3][1,2,4]triazino[5,6-b]indol-4-ium halides whose structures were determined by ¹H NMR and X-ray analysis.     

Synthesis of new imidazo[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3]thiazole derivatives from 2-amino-4-(2,2-dichlorovinyl)-1,3-thiazole and <Emphasis Type="Italic">N</Emphasis>-(2,2-dichloro-2-phenylethylidene)arenesulfonamides

2-Amino-4-(2,2-dichlorovinyl)-1,3-thiazole reacted with highly electrophilic N-(2,2-dichloro-2-phenylethylidene)- and N-(2,2,2-trichloroethylidene)arenesulfonamides through the exocyclic amino group to give products of nucleophilic addition to the azomethine bond, N-[2,2-di(or 2,2,2-tri)chloro-1-(1,3-thiazol-2-ylamino)ethyl]arenesulfonamides in good yields. Intramolecular heterocyclization of the latter afforded N-[3-(2,2-dichloroethyl)-6-phenylimidazo[2,1-b][1,3]thiazol-5-yl]arenesulfonamides.     

Synthesis,S-alkylation,and fungicidal activity of 4-(benzylideneamino)thioglycolurils

A series of 1,3-disubstituted 4-benzylideneamino-5-thioxohexahydroimidazo[4,5-d]imidazol-2(1H)-ones (thioglycolurils) was synthesized via the reaction of 5,7-disubstituted 3-thioxoperhydroimidazo[4,5-e]-1,2,4-triazin-6-ones with hydroxy-, alkoxy-, and fluorocontaining benzaldehyde derivatives. An alkylation of the obtained thioglycolurils with methyl iodide or 4-bromobenzyl bromide provided the corresponding 6-benzylideneamino-5-alkylsulfanyl-3,3a,6,6a-tetrahydroimidazo[4,5-d]imidazol-2(1H)-ones. The fungicidal activity of some synthesized compounds against pathogens causing diseases of agricultural crops was studied.     

Synthesis of sulfonamide derivatives of pyrido-[2,1-<Emphasis Type="Italic">b</Emphasis>]quinazolin-11-one and pyrido[1,2-<Emphasis Type="Italic">a</Emphasis>]quinazolin-6-one

Methods were developed of indirect introduction of sulfonamide group in the structures of pyrido-[2,1-b]quinazolin-11-one and pyrido[1,2-a]quinazolin-6-one underlain by cyclocondensation of 2-halo-5-(Rsulfamoyl) benzoyl chlorides with derivatives of 2-aminopyridine. The fact of thermal rearrangement of 8-(morpholin-4-ylsulfonyl)pyrido[1,2-a]quinazolin-6-one into isomeric 2-(morpholine-4-ylsulfonyl)pyrido[2,1-b]-quinazolin-11-one was experimentally registered.     

Crystal and molecular structure of 1,3,4,6-etraphenylimidazolio[4,5-<Emphasis Type="Italic">d</Emphasis>]-imidazolium bis(phenylenedioxytetrachlorophosphate)

X-ray diffraction structural study of a novel aromatic 10π-electron system of 1,3,4,6-tetraphenyl-imidazolio[4,5-d]-imidazolium bis(phenylenedioxytetrachlorophosphate) is carried out. The crystals are monoclinic; a = 8.483(2) Å, b = 23.986(4) Å, c = 10.727(2) Å; β = 106.84(2)°; V = 2089.1(7) ų, space group P2₁/n. The compound crystallizes as a salt containing two phenylenedioxytetrachlorophoshate anions per one dication of 1,3,4,6-tetraphenylimidazolio[4,5-d]imidazolium. The cation occupies a special position on the inversion center. There are short C-H...X (X = O, Cl) contacts and π-π-interactions between aromatic fragments in the crystal and their combined effect results in the development of a layered structure.