Regioselective synthesis of 4,7,8,9-tetrahydro-2 H -pyrazolo[3,4- b ]quinolin-5(6 H )-ones. Mechanism and structural analysis
摘要:
Reactions of 5-amino-3-methyl-1H-pyrazole with dimedone and aldehydes afford regioselectivelly tricyclic linear 3,7,7-trimethyl-4,7,8,9-tetrahydro-2H-pyrazolo[3,4-b]quinolin-5(6H)-ones in good yields. Several aspects on this regioselective reaction, such as the reaction mechanism and structural studies of the predominant tautomeric form, are treated. (C) 2001 Elsevier Science Ltd. All rights reserved.