US EPA

7470601 

Journal Article 

ZnCl2催化尿素与苯酚合成氨基甲酸苯酯反应研究 

Tong, T; Wang, XP; Wang, GR; Zhao, XQ; Wang, YJ 

2020 

Zhejiang University 

34 

1 

117-124 

Chinese 

10.3969/j.issn.1003-9015.2020.01.015 

The reaction and mechanism of phenyl carbamate synthesis with urea and phenol were investigated by catalyst screening, orthogonal and single factor experiments and analyzed by Fourier transform infrared spectroscopy. The results show that yield of 64.25% can be obtained using ZnCl2 catalysts under conditions of molar ratio of urea/phenol=1/36, mass ratio of catalyst/total material =1%, reaction temperature of 150 ℃ and reaction time of 9 h. The reaction mechanism is as follows: a new complex forms from urea and ZnCl2 first, i.e. Zn2+ coordinates with oxygen from carbonyl in urea, which leads to more positively charged carbon atom and the carbonyl group is activated. The negatively charged phenoxy group of phenol as a nucleophilic reagent attacks the carbon atom and the nucleophilic substitution reaction happens to produce the target product PC. © 2020, Editorial Board of "Journal of Chemical Engineering of Chinese Universities". All right reserved. 

Phenol; Phenyl carbamate; Reaction mechanism; Urea; Zinc chloride; Catalysis; Catalysts; Chlorine compounds; Fourier transform infrared spectroscopy; Metabolism; Molar ratio; Phenols; Substitution reactions; Urea; Catalyst screening; Negatively charged; Nucleophilic reagent; Nucleophilic substitution reactions; Phenyl carbamate; Reaction mechanism; Reaction temperature; Single-factor experiments; Zinc chloride