[Monitoring the synthesis of N,N-diphenyl urea by IR-online].
IR-online detector, React IRTM 4000, was used to monitor the synthesis of N,N-diphenyl urea from urea and aniline. The concentration changes of the reaction components were obtained according to the characteristic IR absorbance changes of the reactants (urea and aniline) at 1 420 and 1 270 cm(-1) respectively, the intermediate product (monophenylurea) at 1 339 cm(-1) as well as the product (N,N-diphenyl urea) at 1 312 cm(-1). In the present study, the result showed that the synthesis of N,N-Diphenyl urea was carried out by two steps. Firstly, the intermediate product monophenylurea was synthesized from urea and aniline, and then N, N-diphenyl urea was obtained by the reaction of monophenylurea with aniline. It was also shown that the IR-online detector was a fast, simple and exact technique to optimize the reaction time and so the reaction course could be easily controlled. The result of IR-online spectrometry was approved by offline reference high performance liquid chromatography (HPLC) method. As a result, the IR-online spectrometry was superior to HPLC method since it was a nondestructive method without the need to sample the reaction medium.
Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China. yaojiemail@163.com
Jie
J
Yao
Tao
T
Kang
Xiao-Jia
XJ
Hu
Tong
T
Chen
Yong-Cheng
YC
Lei
Gong-Ying
GY
Wang