16379-19-4Relevant academic research and scientific papers
A DIRECT SYNTHESIS OF CARBAMATE ESTER FROM CARBON DIOXIDE, AMINE AND ALKYL HALIDE
Yoshida, Yasuhiko,Ishhi, Shigeru,Yamashita, Tadataka
, p. 1571 - 1572 (1984)
Carbon dioxide reacted with diethylamine and alkyl halide derivatives to give the corresponding alkyl N,N-diethylcarbamate esters in fair yields.
Gas-phase elimination kinetics of ethyl, isopropyl and tert-butyl N,N-diethylcarbamates. Application of Taft-Topsom correlation for substituents other than carbon at the acid side of organic ethyl esters
Herize, Armando,Dominguez, Rosa M.,Rotinov, Alexandra,Nunez, Oswaldo,Chuchani, Gabriel
, p. 201 - 206 (2007/10/03)
The elimination kinetics of ethyl, isopropyl and tert-butyl N,N-diethylcarbamates were investigated in a static reaction vessel over the temperature range 220-400°C and pressure range 17-160 Torr. These reactions are homogeneous, unimolecular and follow a first-order rate law. The temperature dependance of the rate coefficients is given by the following equations: for ethyl N,N-diethylcarbamate, log k1 (s-1) = (11.47 ± 0.25) - (178.4 ± 3.1) kJ mol-1 (2.303 RT)-1, for isopropyl N,N-diethylcarbamate, log k1 (s-1) = (12.83 ± 0.70) - (179.8 ± 7.9) kJ mol-1 (2.303 RT)-1; and for tert-butyl N,N-diethylcarbamate, log k1 (s-1) = (12.87 ± 0.62) - (158.6 ± 6.2) kJ mol-1 (2.303 RT)-1. The branching of the alkyl groups at the alcohol side of the ester exerts a significant effect on the rates in the order tert-butyl > isopropyl > ethyl. In addition, the presence of different substituents other than carbon at the acid side of organic ethyl esters gives the best correlation when using the Taft-Topsom equation: log k/kH = -(0.68 ± 0.12)σs + (2.57 ± 0.12)σF - (1.18 ± 0.27)σR (r = 0.984 ± 0.119 at 400°C). According to this relationship, the field (inductive) effect of the substituent has the greatest influence on rate enhancement, while the polarizability (steric) and resonance factors, although small in effect, favour the elimination process. Copyright
Novel Synthesis of Carbamate Ester from Carbon Dioxide, Amines, and Alkyl Halides
Yoshida, Yasuhiko,Ishii, Shigeru,Watanabe, Masayo,Yamashita, Tadataka
, p. 1534 - 1538 (2007/10/02)
A novel synthesis of carbamate ester using carbon dioxide as a direct material is reported in this article.The direct reaction of carbon dioxide, aliphatic amines, and alkyl halides was found to give the corresponding alkyl carbamate esters in good yields.Reactions using secondary alkyl bromides gave carbamate esters in higher yields than those using primary or tertiary alkyl bromides.The carbamate ester yields increased with the addition of N,N-dimethylformamide to the reaction system of carbon dioxide, amines, and alkyl halides.This reaction is considered to prooced by an SN2 displacement reaction of the alkyl halide by the carbamate anion formed from the reaction of carbon dioxide and the amine.
