Pyrazoloquinoline derivative

The other angular pyrazoloquinoline derivative 327 was obtained by hydrazinolysis of 2-imino-7,7-dimethy-4-methylsulfanyl-5-oxo-5,6,7,8-tetrahydro-2H-benzopyran-3-carbonitrile (326). The reaction can be proceeded by substitution of the methylsulfanyl group by hydrazine followed by cyclization to give 327 (97JCR(S)256) (Scheme 61). 

Pyrazolo-based organic materials belong to the most promising blue electroluminescent and transporting materials. A series of pyrazoloquinoline derivatives have been synthesized for use in LEDs. Their optical properties can be tuned by the modification of the side groups. 4-Methyl-pyr-azolo[3.4-b]quinoline emits at 440-460 nm. ... 

For 3-aryl-5-aminopyrazoles 222 the direction of the multicomponent reaction with cyclic P-diketones and aromatic aldehydes is not so unequivocal. Quiroga et al. [190] found that during refluxing of these starting materials in ethanol, the reaction products were only derivatives of pyrazoloquinoline 227,... 

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