One-pot synthesis of 3D-ZIF-7 supported on 2D-Zn-Benzimidazole-Acetate and its catalytic activity in the methoxycarbonylation of aniline with dimethyl carbonate

Abstract

For the first time, three-dimensional Zeolitic Imidazole Framework (3D) ZIF-7 (Zn(BeIM)(2), BeIM = benzimidazole) supported on two-dimensional (2D) Zn(BeIM)OAc (Zinc-Benzimidazole-Acetate) was synthesized by reacting Zn(OAc)(2) and benzimidazole in a one-pot reaction. By modulating the amount of diethylamine during the reaction, the ZIF-7/Zn(BeIM)OAc with a 1 to 1 molar ratio was obtained when the reactant molar ratio of Zn(OAc)(2) and benzimidazole was 1 to 1.5. It was found that 3D-ZIF-7 was synthesized first and then transformed into 2D-Zn(BeIM)OAc by the reaction with remaining Zn(OAc)(2). The synthesized ZIF-7 (Zn(BeIM)(2)) supported on Zn(BeIM)OAc (1/1) showed enhanced catalytic performance in the methoxycarbonylation of aniline with dimethyl carbonate. The yield of methyl N-phenyl carbamate reached 92.0% in 2 h at 190 degrees C, which was higher than yields obtained using the single component catalysts ZIF-7 (69.9%) and Zn(BeIM)OAc (35.4%). Furthermore, this catalyst was successfully reused four times, maintaining an MPC yield of 92.0%-95.8%. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.