Synthesis of 1-hydroxy-substituted pyrazolo [3,4-c]-and pyrazolo [4,3-c] quinolines and -isoquinolines from 4- and 5- aryl-substituted 1-benzyloxypyrazoles

The pyridine ring of pyrazoloquinolines 14 and 18 was formed via cyclization of a formyl group at C-4 or C-5 and an amino group of a 2-aminophenyl substituent at C-5 or C-4 in 1-benzyloxypyrazole. The order of reactions and use of protecting groups in the individual sequences have been optimized.