Catalyst-free efficient synthesis of polyhydroquinolines using polyethylene glycol as a solvent and evaluation of their cytotoxicity

An eco-friendly one-pot synthesis of polyhydroquinolines by four-component coupling of aldehydes, dimedone, ethylacetoacetate, and ammonium acetate using polyethylene glycol as a solvent at room temperature has been accomplished. The conversion was complete within 2-4 h, and the products were formed in high yields (83-95 %). No any additional catalyst was required. Several known and unknown polyhydroquinolines have been prepared. Some of the compounds exhibited impressive cytotoxic activity.