Synthesis of new pyrazolopyrano-quinolin-5-amine derivatives under ultrasonic conditions

Tacrine which acts as a cholinesterase inhibitor is a well-known structure and was primarily studied for its antibacterial and later demonstrated various bilological properties.1 The synthesis and pharmaceutical behavior of Tacrine is studied in detail and reviewed recently.2 In this work, we report the synthesis of a new series of tacrine-coumarin structures which are synthesized through a 4-component process combining ethyl acetoacetate, hydrazines, malononitrile, and vatrious aromatic aldehdes under ultrasonic conditions, followed by a condensation reaction with cycloalkanones to get to the final tetracyclic structures (Fig 1).

Keywords:

Multicomponent reactions , 6-Amino-1 , 4-dihydropyrano-[2 , 3-c]pyrazole-5 carbonitrile , Alzheimer’s disease , Tacrine-Coumarins , 1 , 2 , 3-Triazole