A novel substrate directed multicomponent reaction for the syntheses of tetrahydro-spiro[pyrazolo[4,3-f]quinoline]-8,5′-pyrimidines and tetrahydro-pyrazolo[4,3-f]pyrimido[4,5-b]quinolines via selective multiple C–C bond formation under metal-free conditions |
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Authors: | Divyang M Patel Hetal J Patel Jos M Padrn Hitendra M Patel |
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Institution: | Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar, 388120 Gujarat India.; BioLab, Instituto Universitario de Bio-Orgánica Antonio González, CIBICAN, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez 2, 38206 La Laguna Spain |
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Abstract: | A versatile and substrate oriented multicomponent reaction for the syntheses of novel highly diastereoselective tetrahydro-1′H-spiropyrazolo4,3-f]quinoline-8,5′-pyrimidine]-2′,4′,6′(3′H)-triones (d.r. up to 20 : 1 (syn : anti)) and tetrahydro-8H-pyrazolo4,3-f]pyrimido4,5-b]quinoline-8,10(9H)-diones via formation of selective multiple C–C bonds under identical reaction conditions (viz. ethanol as a reaction medium and deep eutectic mixture as a catalyst) is demonstrated. Both approaches involve mild reaction conditions, use of non-hazardous solvents, and facilitate good to excellent reaction yields of the target compounds.Substrate selectivity in the novel multi-component reaction of 5-aminoindazole, barbituric acid derivatives and aldehyde is explored. |
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