Synthesis of methyl 4-methyl-2-oxo-1,2,5,6-tetrahydro-4H-pyrrolo[3,2,1-ij]quinoline-6-carboxylate

Russian Journal of Organic Chemistry -     

Bromine-substituted 1,2,3,4-tetrahydro-4-methylspiro[quinoline-2-cyclohexanes]

The bromination of 1,2,3,4-tetrahydro-4-methylspiro[quinoline-2-cyclohexane] has been carried out under various conditions. Dibromo and monobromo derivatives have been obtained; the monobromo derivatives were synthesized by cyclization of 1-allyl-1-bromophenylaminocyclohexanes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1350–1353, October, 1991.     

1, 3-dipolar cycloaddition of diazomethane to azolopyridazines. The synthesis of 8-methyl-8H- and 9-methyl-9H-pyrazolo[3, 4-d]-s-triazolo[4, 3-b]pyridazine and 1-methyl-1H- and 2-methyl-2H-imidazo[1, 2-b]pyrazolo[3, 4-b]pyridazine derivatives

The transformations of 7-methyl-7H- and 8-methyl-8H-pyrazolo[4, 3-d]tetrazolo[1, 5-b]pyridazines 1, 2, 9 and 10 into 8-methyl-8H- and 9-methyl-9H-pyrazolo[3, 4-H]-s-triazolo[4, 3-b]pyridazines 7 and 8 , and 1-methyl-1H-and 2-methyl-2H-imidazo[1, 2-b]pyrazolo[3, 4-d]pyridazines 13 and 14 are described.     

Synthesis of 2-aryl-oxazolo[4,5-c]quinoline-4(5H)-ones and 2-aryl-thiazolo[4,5-c]quinoline-4(5H)-ones

[reaction: see text] Novel and highly efficient syntheses of oxazolo[4,5-c]quinoline-4(5H)-ones (1) and thiazolo[4,5-c]quinoline-4(5H)-ones (2) from ethyl 2-chlorooxazole-4-carboxylate (4) and ethyl 2-bromo-5-chlorothiazole-4-carboxylate (13), respectively, are described.     

Synthesis and antibacterial activity of ethyl 2-amino-6-methyl-5-oxo- 4-aryl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carboxylate

The three-component reaction of 4-hydroxy-1-methyl-2(1H)-quinolinone, aromatic aldehydes and ethyl cyanoacetate was carried out in the presence of a catalytic amount of 4-dimethyl aminopyridine(DMAP) in aqueous ethanol. The reactions result in the formation of pyranoquinoline derivatives in excellent yields. Antibacterial activity has been evaluated against Gram positive and Gram negative bacteria for some of the synthesized compounds. The results indicated that these compounds are moderately effective against bacterial growth and their effectiveness is highest against Pseudomonas aeruginosa.     

Synthesis and nitration of 4,6(4,8)-dimethyl-4-methyl-6(8)-methoxy-1,2,3,4-tetrahydrospiro [quinoline-2-cyclohexanes]

The cydization of 1-allyl-1-arylaminocyclohexanes under conditions of acid catalysis afforded 1,2,3,4-tetrahydro-4-methylspiro [quinoline-2-cyclohexanes] methyl (methoxy)-substituted in the phenylene ring. Their mono- and dinitro derivatives were synthesized, and their structure was established. Propositions on the direction of the nitration reaction of these heterocyclic compounds were expressed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 784–788, June, 1993.     

Benzo- and indoloquinolizine derivatives. I. Synthesis of 4b,5,6,7,8,8a,10,11,16,16b-decahydrodibenz[f,h] indolo[2,3-a] quinolizine

Two 4b 5,6,7,8,8a,10,11,16,16b-decahydrodibenz[f,h]indolo-[2,3-a]quinolizine epimers have been synthesized starting from trans-1,2,3,4,4a,10b-hexahydrophenanthridine. The structural assignment of both isomers is discussed by use of ir and pmr spectroscopy.     

Metallations of 5 H-dibenz [b,f] azepine and 10,11-dihydro-5H-dibenz [b,f] azepine. Synthesis of 4-substituted derivatives

The synthesis of 4-substituted 5 H-dibenz [b, f] azepines and 10, 11-dihydro-5 H-dibenz [b, f] azepine resulting from the reaction of the corresponding 4, 5-dilithio derivatives and different N, N-dimethylamides is reported. The total assignment of the pmr spectra of the prepared formyl derivatives based on decoupling experiments is also described.     

Formation of alkyl 1-methyl-3,9-dioxo-2-phenyl-2,3,4,9-tetrahydro-1H-pyrrolo[3,4-b]quinoline-1-carboxylates by thermolysis of alkyl 1,5-diaryl-4-methyl-2,3,6-trioxo-1,2,3,4,5,6-hexahydropyrrolo[3,4-b]pyrrole-4-carboxylates

Russian Journal of Organic Chemistry -     

Arene imine derivatives of nitrogen heterocycles: 1a,9b-dihydrobenz[h]-azirino[f]quinoline, 1a,9b-dihydrobenz[f]azirino[h]quinoline and 1a,9b-dihydroazirino[f][1,10]phenanthroline

The syntheses of the K-imine derivatives of benzo[h]quinoline ( 1 ), benzo[f]quinoline ( 2 ) and 1,10-phenanthroline ( 3 ) are described. The parent nitrogen heterocycles were oxidized with sodium hypochlorite to the corresponding K-oxides, 4, 6 and 8 , which in turn were reacted with sodium azide. The resulting azido alcohols were then cyclized with triethyl phosphite to the title compounds 5, 7 and 9 . The oxirane ring cleavage in benzo[h]quinoline 5,6-oxide ( 4 ) and in benzo[f]quinoline 5,6-oxide ( 6 ) by sodium azide proceeded by the predicted regioselectivity: 4 gave trans-5-azido-5,6-dihydro-6-benzo[h]quinolinol ( 11 ) and trans-6-azido-5,6-dihydro-5-benzo[h]quinolinol ( 10 ) as the major and minor products respectively, and 6 yielded solely trans-6-azido-5,6-dihydro-5-benzo[f]quinolinol ( 12 ). The latter compound proved by X-ray analysis to crystallize as a hydrogen bonded dimer.     

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 1,2,4-triazolo[4,3-a]quinoline-9-, 1,2,3,4-tetrazolo[4,3-a]quinoline-9 and 1,2,4-triazino[4,3-a]quinoline-10-carboxylic acids from 2-chloro- and 2-hydrazinocinchoninic acids

Treatment of 2-chlorocinchoninic acid with hydrazine gives 2-hydrazinocinchoninic acid and with aroylhydrazines to give 1,2,4-triazolo[4,3-a]quinoline-9-carboxylic acids. These are also prepared by the action of benzoyl chloride or the carboxylic acid on 2-hydrazinocinchoninic acid. With pyruvic acid the latter gives 3-methyl-4-oxo-1,2,4-triazino[4,3-a]quinoline-10-carboxylic acid and with nitrous acid gives 1,2,3,4-tetrazolo[4,3-a]quinoline-9-carboxylic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1227–1229, September, 1991.     

Synthesis of 8,9-difluoro-2-methyl-6-oxo-1,2-dihydropyrrolo[3,2,1-ij]quinoline-5-carboxylic acid

A new and efficient seven-step synthesis of 8,9-difluoro-2-methyl-6-oxo-1,2-dihydropyrrolo[3,2,1-ij]-quinoline-5-carboxylic acid ( 9 ), an important intermediate used in the synthesis of quinolone antibacterials, has been developed beginning with commercially available 2,3,4-trifluoronitrobenzene. Selective displacement of the 2-fluorine of the starting material with the anion of ethyl acetoacetate and subsequent hydrolysis and decarboxylation affords the arylacetone derivative 11 . Reduction of the ketone and nitro groups of 11 followed by condensation with diethyl ethoxymethylenemalonate gives 14 , which is cyclized to the indole derivative 15 by the Mitsunobu procedure. Friedel-Crafts cyclization of 15 and acid hydrolysis gives the title compound 9 .