Pyrazolo quinoline

Tricyclic pyrazolo-quinolines 239 were prepared from /1-chloro arylalde-hydes and hydrazine derivatives under microwave irradiation with an acid support [156]. The method, appHed to a series of tricyclic compounds (Scheme 89), can be used, in principle, also for the synthesis of bicycHc and even monocycHc pyrazoles. 

Similarly, arylaminopyrazolone (93) may be transformed into a pyrazolo-quinoline (94) preferably in two steps.71... 

Wentland M, Aldous S, Gruett M, Pemi R, Powles R, Danz D, KlingbeU K, Peverly A, Robinson R, Corbett T, Rtike J, Coughlin S (1995) The antitumor activity of novel pyrazolo-quinoline derivatives. Biooig Med Chem Lett 5 405-410... 

Finally, some results obtained from indazoles substituted in the carbocycle are of interest, even though in these cases the reaction does not involve the heterocyclic moiety (Section 4.04.2.3.2(ii)). For example, pyrazolo[3,4-/]- (566) and pyrazolo[4,3-/]-quinolines (567) have been obtained from aminoindazoles by the Skraup synthesis (76JHC899). Diethylethoxy-methylenemalonate can also be used to give (566 R = C02Et, R = OH) (77JHC1175). Pyrazolo-[4,3-/]- and -[4,3-g]-quinazolones (568) and (569) have been obtained from the reaction of formamide with 5-amino-4-methoxycarbonyl- and 6-amino-5-carboxyindazole, respectively (81CB1624). 

Pyrazolopyrimidinones C NMR, 5, 308 methylation, 5, 310 synthesis, 5, 329 Pyrazolopyrimidinones, thioxo-synthesis, 5, 324 Pyrazoloquinazolines synthesis, 5, 317, 322 Pyrazolo[ 1,5-n]quinazolines synthesis, 5, 273 Pyrazolo[ 1,5-c]quinazolines synthesis, 5, 324 Pyrazolo[2,3-n]quinazolines synthesis, 3, 378 Pyrazoloquinazolinones synthesis, 5, 342 Pyrazolo[4,3-/]quinazolinones synthesis, 5, 273 Pyrazolo[4,3-g]quinazolinones synthesis, 5, 273 Pyrazolo[3,4-/]quinolines synthesis, 5, 273 Pyrazolo[4,3-/]quinolines synthesis, 5, 273 Pyrazolo[l,5-n]quinoxalines synthesis, 5, 339 Pyrazolo[3,4-6]quinoxalines synthesis, 5, 272... 

Synthesis of pyrazolo[l,5-<2]quinolines and related reduced derivatives 97H(45)1839. 

Nitroquinoline (138) undergoes direct cyclocondensation with aromatic hydra-zones 139 in the presence of sodium hydride in DMF to give low yields of the corresponding [l,2,4]triazino[6,5-fc]quinolines 140 and pyrazolo[3,4-/] quinolines... 

Treatment of pyrazolo[l,5-a]quinoline-3,3,4-tricarboxylates 79 with CS2CO3 afforded 2,3-dihydro-l//,7//-pyrido[3,2,l-i/]cinnoline-3,3,8-tricar-boxylates 80 (96BCJ1371). 

Treatment of pyrazolo[l,5- ]quinoline-3,3,4-tricarboxylates 75 with Cs2C03 afforded 2,3-dihydro-177,777-pyr-ido[3,2,l-(/]cinnoline-3,3,8-tricarboxylates 76 (Equation 15) <1996BCJ1371>. 

A series of antimicrobial pyrazolo[3,4-<7]pyrimidines containing 8-(trifluoromethyl)quinoline have been synthesized from 5-amino-1-[8-... 

Pyrazolo-[3,4i>]-quinolines and -pyrazoles have been synthesized by reacting [i-chlorovinylaldehydes and hydrazine or phenyl hydrazine using a catalytic amount of p-toluenesulfonic acid (PTSA) under the action of microwave irradiation. The yields are much better than under the action of A using the same conditions [105] (Eq. 55). 

Y.T. Tao, E. Balasubramaniam, A. Danel, B. Jarosz, and P. Tomasik, Sharp green electroluminescence from 177-pyrazolo[3,4-6]quinoline-based light-emitting diodes, Appl. Phys. Lett., 77 1575-1577 (2000). 

Quiroga and co-authors [101] also reported eco-friendly solvent-free approach to the synthesis of fused benzo[fjpyrazolo[3,4-b]quinolines 72 by three-component reaction of 5-aminopyrazoles, aldehydes, and p-tetralone accomplished by fusion procedure (Scheme 32). However, this method was found inapplicable for the similar reaction of a-tetralone - multicomponent procedure allowed obtaining only bispyrazolopyridines 74 instead of benzo[h]pyrazolo[3,4-b]quinolines 73. According to these experimental results, the latter were generated via preliminary synthesis of arylidentetralones 75. 

Quiroga J, Mejia D, Insuasty B et al (2001) Regioselective synthesis of 4, 7, 8, 9-tetrahydro-2H-pyrazolo[3, 4-b]-quinolin-5(6H)-ones. Mechanism and structural analysis. Tetrahedron 57(32) 6947-6953... 

Jarro Q, Braulio I, Angelina H et al (1998) Synthesis of 4-aryl-4, 7, 8, 9-tetrahydro-6H-pyrazolo[3, 4-b]quinolin-5-ones. J Heterocycl Chem 35(3) 575-578... 

A number of methods are available for the synthesis of fused pyrazoles, the most commonly used method involves the reaction of (3-chlorovinylaldehydes with hydrazine hydrate or phenyl hydrazine. This reaction has been employed by Loupy and coworkers in the microwave-assisted synthesis of pyrazolo [3,4-i> ] quinolines and pyrazolo [3,4-c]pyrazoles (Scheme 3.47)75. 

Paul, S., Gupta, M., Gupta, R. and Loupy, A., Microwave-assisted solvent-free synthesis of pyrazolo [3,4-/7]quinolines and pyrazolo[3,4-c]pyrazoles using p-TsOH, Tetrahedron Lett., 2001, 42, 3827-3829. 

Keywords / -chlorovinylaldehyde, hydrazine, microwave irradiation, pyrazo-lo[3,4- ]quinoline, pyrazolo[3,4-c]pyrazole, pyrazole... 

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