4-functionally substituted 3-heterylpyrazoles: XVIII. Intramolecular cyclization of N -[3-(2-Chlorophenyl)-4-pyrazolyl]methylamine and its N-alkyl derivatives into 4,5-dihydro-2 H -pyrazolo[4,3- c ]quinolines

N-[3-(2-Chlorophenyl)-4-pyrazolyl]methylamine and its N-alkyl-derivatives at heating in DMF in the presence of K₂CO₃ undergo an intramolecular cyclocondensation yielding 4,5-dihydro-2H-pyrazolo[ 4,3-c]quinolines. Original Russian Text ? M.K. Bratenko, O.I. Panimarchuk, V.A. Chornous, M.V. Vovk, 2007, published in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 8, pp. 1213–1216. For Communication XVII see [1].     

Synthesis of new imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-one derivatives by iodocyclization of 6-alkenyl(alkynyl)-aminopyrazolo[3,4-d]pyrimidin-4(5H)-ones

6-Allyl(diallyl, prop-2-yn-1-yl)amino-1-R-pyrazolo[3,4-d]pyrimidin-4(5H)-ones reacted with iodine to give angularly fused 8-iodomethyl-7,8-dihydro-1-R-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-ones which were treated with sodium acetate to obtain 8-methylidene-1-R-7,8-dihydroimidazo[1,2-a]pyrazolo-[4,3-e]pyrimidin-4(6H)-ones as a result of elimination of hydrogen iodide. 8-Methylidene-1-R-7,8-dihydroimidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-ones were converted into 8-methyl-1-R-imidazo[1,2-a]pyrazolo-[4,3-e]pyrimidin-4(5H)-ones on heating to the melting point. 8-Methylidene-1-phenyl-7,8-dihydroimidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-one underwent isomerization into linearly fused 6-methyl-1-phenyl-1,8-dihydro-4H-imidazo[1,2-a]pyrazolo[3,4-d]pyrimidin-4-one on heating in sulfuric acid.     

Pyrano[4,3-d]pyrimidinium salts 3. Reactions of 1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium salts with azomethines

Reactions of 1,3-dimethyl-2,4-dioxo-1H,3H-pyrano[4,3-d]pyrimidinium salts with azomethines have been studied. The reactions lead to 1,3-dimethyl-2,4-dioxo-1H,3H-pyrido-[4,3-d]pyrimidinium salts and aromatic aldehydes.     

The synthesis and transformations of 9H-imidazo[1,2-b]pyrazolo[4,3-d]-pyridazine and 9H-pyrazolo[4,3-d]-s-triazolo[4,3-b]pyridazine derivatives

The nucleophilic and electrophilic substitutions of 6-substituted 9,9-dimethyl-9H-imidazo[1,2-b]pyrazolo- [4,3-d]pyridazines 2 , nucleophilic substitutions of 6-substituted 9,9-dimethyl-9H-pyrazolo[4,3-d]-s-triazolo- [4,3-b]pyridazines 7 and some other transformations to give compounds 3 and 8 , respectively, were studied. It was shown that both heterocyclic systems are stable under the conditions employed in these transformations.     

5-Arylidene Derivatives of Meldrum’s Acid as Synthons in Pyrano[4,3-b]pyran Synthesis

The reactions of 5-arylidene derivatives of Meldrum’s acid with ethyl vinyl ether or N-vinyl-2-oxazolidinone yielded trans-trans-(2,4:4,7)-pyrano[4,3-b]pyrans, cis-trans-(2,4:4,7)-pyrano[4,3-b]pyrans, or diastereoisomeric mixtures of pyrano[4,3-b]pyrans and reactions with 3,4-dihydro-2H-pyran afforded Michael adducts. The reactions of 5-arylidene derivatives of Meldrum’s acid with cyanoacetic acid derivatives do not provide appropriate pyrans.     

Solid-phase synthesis of 2-alkylidene-6-alkyl-imidazo[2,1-b]thiazole-3,5[2H,6H]-dione derivatives

A solid-phase synthesis of 2-alkylidene-6-alkyl-imidazo[2,1-b]thiazole-3,5[2H,6H]-dione derivatives is reported. The desired products were obtained in good purities and yields.     

Synthesis of pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines

Starting from 1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-ones, a synthesis pathway to the tricyclic pyrazolo[4,3-e][1,2,4]triazolo[4,3-c]pyrimidines is described. Reaction of 1,5-dihydro-4H-pyrazolo[3,4-d] pyrimidin-4-ones with phosphoryl chloride afforded the corresponding 4-chloro-1H-pyrazolo[3,4-d]pyrimidines. Treatment of these compounds with hydrazine hydrate at reflux temperature gave the hydrazino derivatives, which were subsequently cyclized to the titled compounds on heating with orthoesters in ethanol.     

Synthesis and antiviral evaluation of some novel [1,2,4]triazolo[4,3-β][1,2,4]triazole nucleoside analogs

Ribosylation of 3-amino-5H-[1,2,4]triazolo[4,3-b][1,2,4]triazole ( 1 ) with l-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose and stannic chloride resulted in the following protected nucleoside analogs: 3-amino-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)[1,2,4]triazolo[4,3-β][1,2,4]triazole ( 4 ), 3-amino-1-(2,3,5-tri-O-benzoyl-α-D-ribofuranosyl)[1,2,4]triazolo[4,3-β][1,2,4]triazole ( 5 ), 3-amino-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)[1,2,4]triazolo[4,3-β][1,2,4]triazole ( 5 ), and 3-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl) amino-5H-[1,2,4]triazolo[4,3-b]-[1,2,4]triazole ( 7 ). Compounds 4–6 were deprotected to 3-amino-1-β-D-ribofuranosyl[1,2,4]triazolo[4,3-b][1,2,4]-triazole ( 3 ), 3-amino-1-α-D-ribofuranosyl[1,2,4]triazolo[4,5-b][1,2,4]triazole ( 8 ), and 3-imino-2H-2-β-D-ribo-furanosyl[1,2,4]triazolo[4,3-b][1,2,4]triazole ( 9 ), while 7 could not be deprotected without decomposition. Compounds 1, 4, 6, 7 , and 9 were screened and found to have no antiviral activity.     

Five-membered 2,3-dioxoheterocycles: LXXXIV. [4+2]-Cycloaddition of styrene to 4,5-diaroyl-1H-pyrrole-2,3-diones. Crystal and molecular structures of 7a-(2,5-dimethylbenzoyl)-4-(2,5-dimethylphenyl)-1-(4-methoxyphenyl)-6-phenyl-7,7a-dihydropyrano[4,3-b]-pyrrole-2,3(1H,6H)-dione

1-Aryl-4,5-diaroyl-1H-pyrrole-2,3-diones react with styrene to form substituted 7,7a-dihydropyrano[4,3-b] pyrrole-2,3(1H,6H)-diones whose structure was confirmed by XRD analysis. The crystal and molecular structure of 7a-(2,5-dimethylbenzoyl)-4-(2,5-dimethyl-phenyl)-1-(4-methoxyphenyl)-6-phenyl-7,7a-dihydropyrano[4,3-b] pyrrole-2,3(1H,6H)dione was examined.     

Sur quelques analogues fluores des [1] benzothiopyrano[4,3-b]indoles et des 6H[1] benzothiopyrano[4,3-b] quinoleines

2-, 3-, and 4-Fluorinated analogs of the carcinogenic [1]-benzothiopyrano[4,3-b]indoles and of 6H[1]benzothiopyrano-[4,3-b]quinolines have been synthesized from the corresponding fluorothiochromanones. Nmr spectral data (at 60 Mc) of the six base molecules are reported. Biological tests for the possible carcinogenic activity of these new compounds, currently under way, have already shown one of them to be a powerful sarcomagen.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones VII. Synthesis of 2H,5H-[1]benzothiopyrano[4,3-b]pyran and 2H,5H-thiopyrano[4,3-b]pyran derivatives

The dipolar 1,4-cycloaddition of dichloroketerie to N,N-disubslituled 3-aminomethylene-2,3-dihydro-4-thiochromanones and 3-aminomethylenetelrahydro-4-thiopyranones gave N,N-disubstituted 4-amino-3,3-diehloro-3,4-dihydro-2H,5H-[1]benzolhiopyrano[4,3-b]pyran-2-ones and 4-amino-3,3-dichloro-3,4,7,8-tetrahydro-2H,5H-thiopyrano[4,3-b]pyran-2-ones, respectively, only in the ease of aromatic or strong hindering aliphatic N-substitution. The adducts gave N,N′-disubstituted 4-amino-3-chloro-2H,5H-[1]benzothiopyrano[4,3-b]pyran-2-ones and 4-amino-3-chloro-7,8-dihydro-2H,5H-thiopyrano[4,3-b]pyran-2-ones, respectively, by dehydro-chlorination with DBN. By chromatography on neutral alumina, 3-(2,2-dichloroethylidene)-2,3-dihydro-4-thiochromanone was isolated as an unstable liquid from the reaction between dichloroketerie and 3-diethylaminornethylene-2,3-dihydro-4-thiochromanone.     

A reinvestigation of the synthesis of 3H-[1,2]diazepino[5,6-b]indoles. The synthesis of pyrido[4,3-b]indoles

Recently reported [1] syntheses of 6-methyl-1,2,4,5-tetrahydro-1,4-dioxo-3H[1,2]diazepino[5,6-b]indole ( 5 ) and 4-hydroxy-6-methyl-3H[1,2]diazepino[5,6-b]indole ( 12 ) were reinvestigated and shown to be in error. The correct assignments for these respective structures are 3-amino-1,9-dihydro-9-methyl-2H-pyrido[4,3-b]indol-2,4(3H)-dione ( 6 ) and 3-amino-3,9-dihydro-9-methyl-2H-pyrido[4,3-b]indol-2-one ( 13 ). Condensation of 6 and 13 with p-nitrobenzaldehyde produced benzylidene derivatives, which confirmed the presence of the amino groups.     

The photo cycloaddition of alkenes to s-triazolo[4,3-b] and [2,3-b]pyridazines

s-Triazolo[4,3-b]pyridazine (I) reacted with cyclohexene under the influence of ultraviolet light to yield 4a,5,7,8,8a,9-hexahydro-9-methylene-6H-s-triazolo[1,5-a]indole (IV) and 9-cyanomethyl-4a,5,7,8,8a,9-hexahydro-6H-s-triazolo[1,5-a]indole (V). These products were formed by the addition of the alkene to the 1,8 positions of I with a concurrent cleavage of the N₄? N₅ bond. Similar additions were observed with cyclopentene and 2,3-dimethyl-1,3-butadiene. The isomeric s-triazolo[2,3-b]pyridazine (III) reacted with cyclohexene to form an isomer of IV, 4a,5,7,8,8a,9-hexahydro-9-methylene-6H-s-triazolo[4,3-a]indole (XV) and two [2 + 2] cycloadducts (XVI and XVII).     

Synthesis of New Fused Pirano[4,3-b]pyridine Derivatives

A method was developed for the synthesis of pyrano[4,3-b]thieno[3,2-e]pyridine derivatives based on the reaction of 3-amino-7-ethyl-7-methyl-7,8-dihydro-5H-pyrano[4,3-b]thieno[3,2-e]pyridine-2-carboxylic acid ethyl ester with chloroacetic acid chloride, triethyl orthoformate, hydrazine hydrate, and also phenyl chloroformate. The synthesis of various new representatives of pyrano[2″,3″:5′,6′]pyrido[3′,2′:4,5]thieno[3,2-dl-pyrimidine series was carried out.

     

The photochemical synthesis of novel heterocyclic compounds from s-triazolo [4,3-b] pyridazine,III

s-Triazolo[4,3-b]pyridazine (I) reacted photochemieally with bieyélo[2.2.1] hepla-2,5-diene, 1,5-cyclooctadiene, 1,3-cyclooctadiene, methylene cyclohexane, diethyl cis-1,2,3,6-tetrahydro-phthalate and ethyl 2-cyclopentene-1-acetate to givt: the following products: the endo and exo isomers of 4a, 5, 8a, 9-tetrahydro-9-rnethylene-5,8-rnethano-8H-s-triuzolo[1, 5-a]indole (II) and the endo and exo-9-cyanometliyl products (III and IV) from bicyclo[2.2.1] hepta-2,5-diene; 4a,5,-9, 10, 10a, 11-huxahydro-11-methylene-6H-cycloocta[4,5]pyrrolo[1,2-b]-s-triazole (V) and the 11-cyanomethyl product VI from 1,5-cyclooctadiene: 4a,7,8,9,10,10a-hexahydro-11 -inethylene-11H-cycloocta[4,5]pyrrolo[1,2-b]-s-triazole(VII),4a, 5, 7, 8, 10a, 11-hexahydro-11-methylene-6H-cycloocta[4,5]pyrroIo[1,2-b]-s-triazole (VIII) and their respective 9-cyanomethyl products (X and 1X) from 1,3-cyclooctadiene; 6′, 7′ -dihydro-7′ -methylenespiro[cyclohexane-1, 5′-[5H] pyr-rolo[1,2-b]-s-triazole] (XI), 6′, 7′-dihydro-7′-meth) lene. spiro cyclohexane-1, 6′-[5H]pyrrolo[1,2-b]-s-triazole] (XII) and their respective 7 -eyanomethyl products (XIII and XIV) from melhylene cyclohexane; 6,7-dicarbethoxy-9-cyanomelhyl-4a, 5, 7, 8, 8a, 9-hexahydro-6H-s-triazolo[1,5-a]indole (XV) from diethyl cis-1, 2, 3, 6-tetrahydrophlhalate: and 5-earl)elhoxymethyl-8-eyanomethyl-4a, 5, 6, 7, 7a, 8-hexahydrocyclopenta[4,5]pyrrolo( 1, 2-b]-s-triazole (XVI) from ethyl 2, 2-cyclo-pentene-1-acetate. Many other alkenes, particularly the phenyl ethylenes, did not react with compound 1. In general, more than one product was isolated for each reaction except in the case of the two ester alkenes where a single eyanomethyl product was observed.     

Synthesis of New Chromeno[4,3‐b]pyrazolo[4,3‐e]pyridines Derivatives with Antimicrobial Evaluation

A series of 2‐oxo‐2,5‐dihydro‐1H‐chromeno[4,3‐b]pyridine derivatives were obtained by using a one‐pot three component reaction of 2,2‐disubstituted chroman‐4‐one with aromatic aldehydes and 2‐cyanoacetamide in the presence of sodium hydroxide under solvent‐free conditions. Heating chromenopyridine derivatives with phosphoryl chloride gave the corresponding chloro derivatives. The reaction of the chloro derivatives with hydrazine hydrate afforded dihydrochromeno[4,3‐b]pyrazolo[4,3‐e]pyridines derivatives. Condensation of the dimethyl derivative compound with the aromatic aldehydes gave 8‐Arylideneamino‐6,6‐dimethyl‐10H‐chromeno[4,3‐b]pyrazolo[4,3‐e]pyridine.     

6,6-Heptamethylenetetrahydropyran-2,4-dione in the Synthesis of Benzo[f]pyrano[3,4-b]quinolines and Pyrano[4,3-b][4,7]phenanthrolines

Three-component condensation of 6,6-heptamethylenetetrahydropyran-2,4-dione with 2-amino-naphthalene or 6-aminoquinoline and aromatic aldehydes in an aliphatic alcohol afforded 12-aryl-9,9-hepta-methylene-8,9,10,12-tetrahydro-7H-benzo[f]pyrano[3,4-b]quinolin-11-ones and 12-aryl-9,9-heptamethylene-8,9,10,12-tetrahydro-7H-pyrano[4,3-b][4,7]phenanthrolin-11-ones, new N,O-heterocycles which include azaor diazaphenanthrene system fused to -pyrone ring and aromatic and spiro substituents.     

New synthesis of benzo[b][1,6]naphthyridines and pyrido[4,3-b]benz[f]azepines from lactim ethers of 3,4-dihydrocarbostyril and 1H-2,3,4,5-tetrahydrobenz[b]azepin-2-one

Condensation of lactim ethers of 3,4-dihydrocarbostyril and 1H-2,3,4,5-tetrahydrobenz[b]azepin-2-one with malonodinitrile, cyanoacetamide, and ethyl cyanoacetate gave the corresponding 2-methylidene derivatives. Their reactions with dimethylformamide diethyl acetal followed by cyclization into benzo[b][1,6]naphthyridines and pyrido[4,3-b]benz[f ]azepines were studied. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 995–1002, May, 2007.     

The synthesis of [1]benzothieno[2,3-c]quinolines, [1]benzothieno[2,3-c][1,2,4]triazolo[4,3-a]quinoline,and [1]benzothieno[2,3-c]tetrazolo[1,5-a]quinoline

Photocyclization of 3-chloro-N-phenylbenzo[b]thiophene-2-carboxamide 10 afforded [1]benzothieno[2,3-c]-quinolin-6(5H)-one 11 which was chlorinated to 6-chloro[1]benzothieno[2,3-c]quinoline 12 followed by dechlorination to give [1]benzothieno[2,3-c]quinoline 5 . A series of 6-substituted alkoxy and thioalkoxy[1]benzothieno[2,3-c]quinoline derivatives were prepared along with the N-methyl quaternary salt 13 of 5 . 6-Chloro[1]-benzothieno[2,3-c]quinoline 12 was converted into 6-hydrazino[1]benzothieno[2,3-c]quinoline 23 which upon treatment with formic acid yielded [1]benzothieno[2,3-c][1,2,4]triazolo[4,3-a]quinoline 6 . Treatment of 23 with nitrous acid resulted in [1]benzothieno[2,3-c]tetrazolo[1,5-a]quinoline 7 . Compounds 6 and 7 are novel heterocyclic ring systems.     

A selective synthesis of 2-arylamino-4H-1,3,4-thiadiazino[5,6-b]-quinoxalines and mesoionic triazolo[4,3-a]quinoxaline

The reaction of the 6-chloro-2-(1-methyl-2-thiocarbamoylhydrazino)quinoxaline 4-oxides 3a-d with trifluoroacetic anhydride gave the 2-(N-aryl)trifluoroacetamido-8-chloro-4-methyl-4H-1,3,4-thiadiazino-[5,6-b]quinoxalines 7a-d , respectively, while the reflux of compounds 3a-c in N,N-dimethylformamide afforded the mesoionic triazolo[4,3-a]quinoxaline 4 . Hydrolysis of compounds 7a-d with triethylamine/water provided the 2-arylamino-8-chloro-4-methyl-4H-1,3,4-thiadiazino[5,6-b)]quinoxalines 8a-d , respectively.