Ultrasound-assisted synthesis of pyrazolo[1,2-b]phthalazines and dihydrospiro[indoline-3,1'-pyrazolo[1,2-b]phthalazines] using TBAF as an efficient phase-transfer catalyst

Abstract

Tetrabutylammonim fluoride has been used as an efficient catalyst for synthesis of pyrazolo[1,2-b]-phthalazine-5,10-diones and dihydrospiro[indoline-3,1'-pyrazolo[1,2-b]phthalazines] by one-pot three-component reaction of phthalhydrazide, aromatic aldehydes or isatin derivatives, with malononitrile in water under ultrasond irradiation. This rapid method gave the products in high yield.