Synthesis of thieno [3,4-c ]- and selenopheno[3,4-c] pyrylium salts

Acylation of 3-acetonyl- and 3-phenacyl-2,5-dimethylthiophenes with aliphatic acid anhydrides in the presence of perchloric acid gives thieno[3,4-c]pyrylium perchlorates. Reaction of the latter with ammonia gives the corresponding thieno[3,4-c]pyridines or diketones of the thiophene series. Selenopheno[3,4-c]pyrylium salts could not be isolated in the acylation of 3-acetonyl- and 3-phenacyl-2,5-dimethylselenophenes.     

Recyclization of perhydrooxazolo[5,4-c]pyridines to 5,6,7,8-tetrahydrooxazolo[3,4-c]pyrimidines

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 855–856, June, 1991.     

Polymethyl derivatives of furo[3,4-c]pyran4-one,furo[3,4-c] pyridin-4-one and pyrrolo[3,4-c]pyran-4-one

The: title compounds were prepared from Michael adducts, obtained from acetoacetic esters and trans-3-hexene-2,5-dione, and from the corresponding dehydration products, by direct cyclization to oxygen rings or by reaction with ammonia (or methylamine) to give nitrogen rings.     

Condensation reaction of 3,4-dibenzoyl-1-methyl-2,5-diphenylpyrrole and -1-phenylpyrazole with methylamine derivatives affording pyrrolo [3,4-c]pyridine and 2H-pyrazolo[3,4-c]- and [4,3-c]pyridines

The reaction of 3,4-dibenzoyl-1-methyl-2,5-diphenylpyrrole ( 1 ) and -1-phenylpyrazole ( 2 ) with methylamines ( 3a-c ) afforded pyrrolo[3,4-c]pyridine ( 4 ), and isomeric 2H-pyrazolo[3,4-c]pyridines ( 5a-c ) and [4,3-c]pyridines ( 6a-c ), respectively.     

Synthesis of thieno[3,4-c] and thieno[3,2-c][2,1]benzothiazepines

Starting from [4,3-c] and [3,2-c] methyl chlorosulfonylthiophenecarboxylates the synthesis of ketones 7 and 8 is described. These compounds are the first two representatives of the new thieno[3,4-c] and thieno-[3,2-c][2,1]benzothiazepine ring systems. The formation of methyl 3-chlorosulfonylthiophene-2-carboxy-late is also revised.     

Inhibitors of platelet aggregation. 4. [1,2,5]Thiadiazolo[3,4-c]acridines, 7,8,9,10-Tetrahydro[1,2,5] thiadiazolo[3,4-c]acridities,and 8,9-Dihydro-7H-cyclopenta[b][1,2,5] thiadiazolo[3,4-H]quinolines

The condensation of 4-amino-2,1,3-benzothiadiazole (IV) with diphenyliodonium-2-earboxylate gave N-(2,1,3-benzothiadiazoI-4-yl)anthranilic acid (V) (28%), which was cyclized with phosphorus oxychloride to 6-chloro[1,2,5]thiadiazolo[3,4-c]acridine (VI) (84%). Treatment of VI with 3-(dimethylamino)-1-propanethiol hydrochloride in phenol afforded 6-[ [3-(dimethylamino)-propyl]thio] [1,2,5]thiadiazolo[3,4-c]acridine (VII) (65%). The reaction of IV with a mixture of methyl and ethyl 2-oxocyclohexanecarboxylate gave the adduct, which was ring closed in Dowtherm to 7,9,10,1 1-tetrahydro[1,2,5] thiadiazolo[3,4-c]acridin-6(8H)one (VIII) (70%). Chlorination of VIII with phosphorus oxychloride gave 6-chloro-7,8,9,10-tetrahydro[1,2,5]thiadiazolo[3,4-c]acridine (IX) (84%), which was condensed with 3-(dimethylamino)-1-propanethiol hydrochloride in phenol yielding 6-[ [3-(dimethylamino)propyl]thio]-7,8,9,10-tetrahydrof 1,2,5]-thiadiazolo[3,4-c]acridine (X) (27%). 6-[ [3(1)imethylamino)propyl]thio]-8,9-dihydro-7H-cyclopenta[b] [1,2,5]thiadiazolo[3,4-h]quinoline (XIII) (25%) was prepared similarly from IV and a mixture of methyl and ethyl 2-oxocyclopentanecarboxylate via 7,8,9,10-tetrahydro-6H-cyclopenta[b][1,2,5]thiadiazolo[3,4-h]quinolin-6-one (XI) (85%) and 6-chloro-8,9-dihydro-7H-cyclopenta[b][1,2,5]thiadiazolof3,4-h]quinoline (XII) (56%). The effects of compounds VII-XIII as inhibitors of platelet aggregation are discussed.     

Deprotonation and regioselective addition of 2H-pyrazolo[3,4-c]quinolines to electrophiles

The deprotonation and regioselective reaction of 2H-pyrazolo[3,4-c]quinolines with a variety of electrophiles is described. Electrophiles include benzaldehyde, DMF, carbon dioxide, and iodine. This method provides a direct route to a class of pharmacologically interesting compounds.     

Synthesis of 1H-pyrazolo[3,4-e]-s-triazolo[3,4-c]-as-triazines, 8H-pyrazolo[3,4-e]tetrazolo[5,1-c]-as-triazine and 1,7-dihydro-8H-pyrazolo[3,4-e]-as-triazine derivatives

3-Hydrazino-7-methyl-5-phenyl-5H-pyrazolo[3,4-c]-as-triazine 1 underwent ring closure and/or condensation reaction with formic acid, acetic acid, acetic anhydride and benzoyl chloride to afford 1H-pyrazolo-[3,4-d]-s-triazolo[3,4-c]-as-triazines 2, 5 and 7a and/or N-acyl derivatives 3, 4 and 6 . N-Acyl derivatives 3 and 6 underwent cyclisation reaction on treatment with phosphoryl chloride to give 5 and 7a . 3-Methyl-1-phenyl-8-aryl-1H-pyrazolo[3,4-e]-s-triazolo[34,-c]-as-triazines 7 were also prepared by the reaction of the hydrazono derivatives 8 wit thionyl chloride. On treatment of 1 with nitrous acid gave the 8H-pyrazolo[3,4-e]tetrazolo-[5,1-c]-as-triazine 9 . Compound 1 underwent ring closure with carbon disulphide or ethyl chloroformate to 1,7-dihydro-8H-pyrazolo[3,4-e]-s-triazolo[3,4-c]-as-triazine derivatives 10 and 12 . Reaction of 1 with ethyl acetoacetate or acetylacetone gave 3-pyrazolo derivatives 13 and 14 .     

Synthesis and carbon-13 NMR study of 2-benzyl, 2-methyl, 2-aryloctahydropyrrolo [3,4-c] pyrroles and the 1,2,3,5-tetrahydropyrrolo [3,4-c] pyrrole ring system

2-Benzyl, 2-phenyl, 2- (3-methoxyphenyl) and 2-(3-trifluoromethylphenyl) octahydropyrrolo[3,4-c]pyrrole ( 9a, 9b, 9c , and 9d , respectively) were prepared in five steps from 1-benzylpyrrole-3,4-dicarboxylic acid ( 2 ). 2-Methyloctahydropyrrolo [3,4-c]pyrrole ( 9′a ) was prepared analogously in six steps from 1-methylpyrrole-3,4-dicarboxylic acid ( 3 ). Diborane reduction of 1-benzyl-N-methyl-1H-pyrrole-3,4-dicarboximide ( 7′a ) and 1, N-dibenzyl-1H-pyrrole-3,4-dicarboximide ( 7a ) gave 5-benzyl-2-methyl and 2, 5-dibenzyl-1,2,3,5-tetrahydropyrrolo [3,4-c]pyrrole ( 19 ′ and 19 , respectively); the first reported members of the 1,2,3,5-tetrahydropyrrolo[3,4-c]pyrrole ring system. A detailed study of the carbon-13 nmr shifts permitted a complete assignment for all compounds. Mono and disubstituted products produce a systematic effect on the shifts for the bicyclic ring systems which can be readily interpreted in terms of substituent chemical shifts. The effect of protonation at nitrogen is also shown to produce a series of well defined chemical shifts for the octahydropyrrolo [3,4-c] pyrrole ring system.     

Convenient synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] and spiro[acenaphthyl-3,4'-pyrano[2,3-c]pyrazoles] via fourcomponent reaction

The base promoted four-component reaction of hydrated hydrazine, dimethyl acetylenedicarboxylate, isatines and malononitrile (ethyl cycanoacetate) in ethanol afforded polysubstituted spiro[indoline-3,4‘-pyrano[2,3-c]pyrazoles] and spiro[acenaphthyl-3,4-pyrano[2,3-c]pyrazoles]     

Reactions of 1H-pyrano[3,4-c]pyran-7-ium perchlorates with ammonium acetate and amines: synthesis of 2,7-naphthyridines and pyrano[3,4-c]pyridinium salts

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Synthesis and alkylation of pyrazolo[3,4-c]isoquinolines and hexahydrocyclohepta[d]pyrazolo[3,4-b]pyridines

The condensation of 1-acyl-2-(morpholin-4-yl)cycloalkenes with 3-amino-1-phenyl-1H-pyrazol-5(4H)-ones gave the corresponding 2,3,6,7,8,9-hexahydropyrazolo[3,4-c]isoquinoline and 3,6,7,8,9,10-hexahydrocyclohepta[ d]pyrazolo[3,4-b]pyridine derivatives. Alkylation of 2,3,6,7,8,9-hexahydropyrazolo[3,4-c]-isoquinolines with alkyl halides occurred at the nitrogen atom in the 3-position. The structure of 7-methyl-2,5-diphenyl-2,3,6,7,8,9-hexahydro-1H-pyrazolo[3,4-c]isoquinolin-1-one was proved by X-ray analysis.     

Synthesis of 2-aryl-6-carbethoxythiazolo[4,5-c]pyridine and 7-chloro-2-phenylthiazolo[5,4-c]pyridine

Starting from readily available 2-aryl-5-formyl-4-mehtylthiazole, 2-aryl-6-carbethoxythiazolo[4,5-c]pyridine was prepared. β-(2-Phenylthiazol-4-yl)acrylic acid was converted to the corresponding azide (VI). Cyclization of compound VI afforded 2-phenylthiazolo[5,4-c]pyridin-7(6H)one. Reaction of the latter with phosphorous oxychloride gave 7-chloro-2-phenylthiazolo[5,4-c]pyridine.     

Convenient construction of spiro[indoline-3,5'-pyrrolo[3,4-c]carbazole] and spiro[indene-2,5'-pyrrolo[3,4-c]carbazole] via acid-catalyzed Diels-Alder reaction

p-TsOH catalyzed Diels-Alder reaction of 3-(indol-3-yl)maleimides with 3-phenacylideneoxindoles in toluene at 80 °C for two hours afforded cis/trans isomers of 3a',4′,6′,10c'-tetrahydrospiro[indoline-3,5′-pyrrolo[3,4-c]carbazoles] in nearly comparable yields, which could be easily converted to the corresponding 4′,6′-dihydrospiro[indoline-3,5′-pyrrolo[3,4-c]carbazole] in high yields and with high diastereoselectivity by further DDQ oxidation. Additionally, the similar reaction of 3-(indol-3-yl)maleimides with 2-arylidene-1,3-indanediones in toluene 80 °C and sequential DDQ oxidation afforded functionalized dihydrospiro[indene-2,5′-pyrrolo[3,4-c]carbazoles] as major products.     

2H-Pyrrolo[3,4-b]pyridine and 2H-pyrrolo[3,4-c]pyridine: synthesis of the parent ring system and the Diels-Alder reaction

2H-Pyrrolo[3,4-b]pyridine (1) and 2H-pyrrolo[3,4-c]pyridine (2) were prepared and reacted with N-phenylmaleimide to give Diels-Alder adducts.     

Synthesis of 1H-thieno[3,4-c]pyrazoles,thieno[3,4-b]furans,selenolo[3,4-b]furans and pyrrolo[3,4-d]thiazoles

Starting from the readily available aryl 2-methyl-5-phenyl-3-furyl ketones, 5-methyl-1H-1-phenylpyrazole-4-yl ketones and 4-methyl-2-phenyl-5-thiazolylcarboxaldehyde, a series of 2-phenyl-4-arylthieno[3,4-b]-furan, 2-phenyl-4-(p-methoxyphenyl)selenolo[3,4-b]furan, 4-aryl-1H-1-phenylthieno[3,4-c]pyrazole and 5-benzyl-2-phenylpyrrolo[3,4-d]thiazole were prepared in high yield.     

Tetraoxo derivatives of perhydropyrrolo[3,4-c]pyridine

Michael adducts from diethyl fumarate with malonic esters or nitriles were cyclized to succinimide intermediates which, after glutarimide ring closure, afforded several N-methyl and N-benzyl derivatives of cis-1,3,4,6-tetraoxoperhydropyrrolo[3,4-c]pyridine whose configuration was demonstrated by X-ray crystal structure analysis.