Synthesis of 6,7-methylenedioxy-3,4-dihydro-1-methylbenzothieno[2,3-c]pyridine

Synthesis of the title compound, a potential inhibitor of mouse brain monoamine oxidase, is described. The preparation proceeds in eight steps from 1,3-benzodioxole in 1.9% overall yield. The novel hydrogenolysis of an aryl thiocyanate to the aryl methyl sulfide is reported.     

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.     

Methods for the synthesis of 3H-pyrrolo[2,3-c]quinolines

Chemistry of Heterocyclic Compounds - The review examines methods for the preparation of compounds containing the 3H-pyrrolo[2,3-c]quinoline fragment, which have been published mainly over the past...     

Concise and efficient synthesis of 4-fluoro-1H-pyrrolo[2,3-b]pyridine

Two routes describing the preparation of 4-fluoro-1H-pyrrolo[2,3-b]pyridine (4a) from 1H-pyrrolo[2,3-b]pyridine N-oxide (1) are presented. Regioselective fluorination was achieved using either the Balz-Schiemann reaction or lithium-halogen exchange. [reaction: see text]     

The synthesis of 4-benzylamino-6-methyl-1H-pyrrolo[3, 2-c]pyridine and 4-benzylamino-6-methyl-1H-pyrrolo[2, 3-b]pyridine

4-Benzylamino-6-methyl-1H-pyrrolo[3,2-c]pyridine ( 2 ) and 4-benzylamino-6-methyl-1H-pyrrolo[2,3-b]pyridine ( 3 ) were synthesized as deaza analogues of the anxiolytic agent 4-benzylamino-2-methyl-7H-pyrrolo[2,3-d]pyrimidine ( 1 ). The 1-deaza analogue (2) was prepared via a multi-step procedure from a pyrrole precursor, 1-benzyl-2-formylpyrrole ( 4 ) while the 3-deaza analogue 3 was synthesized from a pyridine precursor, 2-amino-3,6-dimethylpyridine ( 12 ).     

Synthesis of 6-Alkoxy- and 1,6-Dialkoxy-4-amino-1-aryl-3-oxo-2,3-dihydro-1H-pyrrolo[3,4-c]pyridine-7-carbonitriles

Russian Journal of Organic Chemistry - Base-catalyzed reaction of 3-aroyl-6-halopyridine-3,5-dicarbonitriles with alcohols involved successive regioselective pyrrole ring fusion at the pyridine [c]...     

Condensed pyridine bases synthesis of some benzo[b]furo[2,3-c]-, benzo[b]- thieno[2,3-c]-, and benzo[b]selenopheno[2,3-c]-quinolines

Summary Condensation of benzo[b]furan-3(2H-one, benzo[b]thiophen-3(2H)-one and benzo[b]selenophen-3(2H)-one with dimedone gives 2-(3-heteryl)dimedones. Acylation of the latter leads to the corresponding tetracyclic pyrylium salts, from which condensed quinolines are obtained. Some condensed quinoline derivatives are obtained by reaction of 1-oxo-1,2,3,4-tetrahydroheterene[2,3-c]quinolines with sodium borohydride, hydrazine, and hydroxylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 321–326, March, 1994.     

Synthesis of 2,3-dioxo-2,3-dihydro-4-methyl-6-chloro-1H-pyrrolo[2,3-b]pyridine and its 1-α-L-arabinopyranoside

A new type of isatin analog-2,3-dioxo-2,3-dihydro-4-methyl-6-chloro-1H-pyrrolo[2,3-b]pyridine — was obtained by oxidation of 4-methyl-6-chloro-1H-pyrrolo(2,3-b]pyridine. Condensation of L-arabinose with 4-methyl-6-chloro-2,3-dihydropyrrolo[2,3-b]pyridine and subsequent acetylation and dehydrogenation gave 1-(2,3,4-tri-O-acetyl--L-arabinopyranosyl)-4-methyl-6-chloropyrrolo[2,3-b]pyridine, which served as the starting compound for the synthesis of 1--L-arabinopyranosyl-4-methyl-6-chloropyrrolo[2,3-b]pyridine. Oxidation of 1-(2,3,4-tri-O-acetyl-L-arabinopyranosyl)-4-methyl-6-chloropyrrolo[2,3-b]pyridine gave 1-(2,3.4-tri-O-acetyl--L-arabinopyranosyl)-2,3-dioxo-2,3-dihydro-4-methyl-6-chloropyrrolo [2,3-b]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1083–1086, August, 1977.     

The Thieno[2,3-c]pyridine Reissert Compound

Thieno[2,3-c]pyridine has been converted to 6-benzoyl- and 6-carbethoxy-7-cyano-6,7-dihydrothieno[2,3-c]-pyridine. Alkylation, condensation, Michael addition, and cyclo addition reactions of these Reissert type compounds have been carried out.     

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]     

Synthesis of 3-formylbenzo[b]furan and 1-methyl-3,4-dihydrobenzo[b]-furo[2,3-c]pyridine

Starting from the readily available 3-methylcoumarilate, 3-formylbenzo[b]furan was synthesized in high yield. The latter could be converted to 1-methyl-3,4-dihydrobenzo[b]furo-[2,3-c]pyridine in moderate yield.     

New polyheterocyclic series based on 4,5,6,7-tetrahydrothieno[2,3-c]pyridine

4,8-Dimethyl-6,7,8,9-tetrahydropyrido[4′,3′:4,5]thieno[2,3-e][1,2,4]triazolo[3,4-a]-4H-pyrimidin-5-ones, 7-methyl-2,3,6,7,8,9-hexahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrrolo[1,2-a]-1H, 10H-pyrimidin-10-one, 8-methyl-1,2,3,4,7,8,9,10-octahydropyrido[4′,3′:4,5]thieno[2,3-d]-11H-pyrimidin-11-one, and 9-methyl-2,3,4,5,8,9,10,11-octahydro[4′,3′:4,5]thieno[2,3-d]azepino-[1,2-a]-1H, 12H-pyrimidin-12-one which consist four new heterocyclic ring systems were synthesized from 2-amino-3-carbethoxy-5-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine.     

The synthesis of monomethoxy[1]benzothieno[2,3-c]quinolines

A series of monomethoxy[1]benzothieno[2,3-c]quinolines 24-28 were prepared by photocylization of the appropriate 3-chloro-N-phenylbenzo[b]thiophene-2-carboxamides 9–13 to [1]benzothieno[2,3-c]quinolin-6(5H)-ones 14-18 followed by chlorination to 6-chloro[1]benzothieno[2,3-c]quinolines 19-23 then dechlorination resulting in the title compounds except for 25 which was achieved by direct reduction of 15 . Reaction of 24-28 with methyl iodide provided the corresponding N-methyl quaternary salts 29-33 . Also, conversion of 4-meth-oxy[1]benzothieno[2,3-c]quinolin-6(5H)-one 16 to 4-methoxy-6-methylthio[1]benzothieno[2,3-c]quinoline 35 and 4,6-dimethoxy[1]benzothieno[2,3-c]quinoline 36 is described.     

New approach for the synthesis of 3H-pyrrolo[2,3-c]isoquinoline derivatives

Synthesis of new 2,3-diaryl-3H-pyrrolo[2,3-c]isoquinoline derivatives has been elaborated starting from isoquinoline-3-amine. Buchwald–Hartwig arylation and subsequent iodination in position 4 afforded 3-arylamino-4-iodoisoquinolines. These compounds were subjected to Sonogashira cross-coupling reactions with some selected acetylenes, and the resulting coupled products underwent cyclization in the presence of tetrabutylammonium fluoride to give title derivatives.