In Situ Carbonylative Synthesis of Aromatic Esters and Formation of Quinazoline‐2,4(1H,3H)‐diones by Chemical Fixation of CO2 in Assistance of Polymer‐Supported Palladium Catalyst

Abstract

AbstractIn this work, a functionalized chloromethylated polystyrene supported polymer complex of palladium was designed and synthesized in the three‐step process. The synthesized heterogeneous Pd(DAP‐DEAS‐MERF) catalyst was characterized by Field emission scanning electron microscopy, Energy dispersive analysis of X‐rays, Elemental mapping, Atomic absorption spectroscopy, N2‐BET adsorption‐desorption isotherm, High‐resolution transmission electron microscopy, Thermogravimetric analysis‐Differential thermal analysis, Powder X‐Ray diffraction and Fourier‐transform infrared spectroscopy. The calculated surface area of the synthesized Pd(DAP‐DEAS‐MERF) catalyst is 4.018 m2/g and palladium content is found to be 5.16 % from AAS analysis. After this, the synthesized catalyst was successfully applied for the synthesis of aromatic esters and quinazoline‐2,4(1H,3H)‐diones in high efficiency. Aromatic esters were synthesized by the in‐situ carbonylative coupling reaction of iodobenzenes and phenols using chlorofirmand KOH as CO source.In the case of quinazoline‐2,4(1H,3H)‐diones synthesis, CO2 fixation reaction was performed with 2‐iodoaniline derivatives and tert‐butyl isocyanide/cyclohexyl isocyanide under atmospheric CO2 pressure. The synthesized products were identified by 1HNMR spectroscopy after purifying by coloum chromatography technique. In this report, Pd(DAP‐DEAS‐MERF) catalyst proved its efficiency by providing a comparatively better reaction condition than the other reported homogeneous and heterogeneous catalytic systems. Additionally, the catalyst isrecyclable up to six times and thermally stable up to 319 °C.