One‐Pot Preparation of Methyl N‐Phenyl Carbamate and Zn(OAc)₂/SiO₂ Catalyst with Enhanced Stability

Abstract

The one-pot preparation of methyl N-phenyl carbamate (MPC) and supported Zn(OAc) 2 /SiO 2 -OP was investigated. Zn(OAc) 2 and SiO 2 were added to the reaction between dimethyl carbonate (DMC) and aniline upon which MPC and Zn(OAc) 2 / SiO 2 -OP were obtained simultaneously. The co-prepared Zn (OAc) 2 /SiO 2 -OP showed superior catalytic performance for MPC synthesis, giving a aniline conversion of 96.3% and a MPC selectivity of 99.7%. Compared with catalyst prepared by incipient impregnation, Zn(OAc) 2 /SiO 2 -OP was more stable during the reaction, and the aniline conversion was 85.0% with MPC selectivity of 88.2% for the seventh time. The catalyst was characterized and the results suggested that Zn(OAc) 2 , Zn 5 (OH) 8 (OAc) 2 ⋅2H 2 O, ZnO and Zn 4 O(OAc) 6 are present on SiO 2 surface. Zn(OAc) 2 and Zn 4 O(OAc) 6 are the active sites for MPC synthesis. The superior stability of the Zn(OAc) 2 /SiO 2 -OP catalyst came from the presence of Zn 4 O(OAc) 6 .

An Escape from Noble Metals for Generating Urethanes via Reductive Carbonylation of Nitroarenes over FeSe2/γ-Al2O3 †

“…Conventionally, the production of urethanes involves the employment of phosgene, which is extremely toxic and harmful to the environment and human beings. Therefore, there have been tons of endeavors for producing carbamates via phosgene-free pathways [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Among them, the catalytic reductive carbonylation of nitroarenes is regarded as one of the promising routes [6][7][8][20][21][22][23][24][25][26][27].…”