This report describes the development of six acidic composites of Y-zeolite with 1,3-disulfoimidazolium trifluoroacetate [Dsim][CF3COO] ionic liquid (IL) and displays the gradual increase of acidic IL mediated dealumination within zeolite framework with increasing loading in Powder XRD and IR studies. The structural changes of modified framework of zeolite were analyzed by SEM-EDX, TEM, TGA, BET and UV-Vis techniques. Out of the six composites, the more acidic [Dsim][CF3COO]/NaY = 20% (e) composite was evaluated as heterogeneous catalyst for multicomponent synthesis of 3,4-dihydropyrimidinones (DHPMs) under neat condition at various temperature.