Current time in Korea 10:15 Apr 25 (Thu) Year 2024 KCS KCS Publications
KCS Publications
My Journal  Log In  Register
HOME > Search > Browsing(JKCS) > Archives

Journal of the Korean Chemical Society (JKCS)

ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 23, Number 4
JKCSEZ 23(4)
August 20, 1979 

 
Title
Studies on the Quaternization of Tertiary Amines (Ⅰ). Kinetics and Mechanism for the Reaction of Phenethyltosylate with Substituted Pyridines

3 차아민의 4 차화반응에 관한 연구 (제1보). Phenethyltosylate 와 치환 피리딘류의 반응에 관한 반응 속도론적 연구
Author
Kyung-A Lee, Kyu-Tag Howang, Soo-Dong Yoh

이경아, 황규탁, 여수동
Keywords
Abstract
Phenethyltosylate와 치환 피리딘의 반응속도를 전기전도법으로 아세트니트릴 용매에서 50, 60, 및 70℃에서 측정하였다. 이 반응에서의 피리딘의 치환기 효과를 검토한 결과 피리딘의 전자주는 능력이 강할 수록 반응은 빨랐다. Eα와 ΔS≠ 사이에는 동속관계가 성립되었고 동속온도는 240。K 였다. Brфnsted 도시는 4-아미노피리딘을 제외하고는 1ogk=0.22pKα-3.7l (r=0.986)의 직선이 얻어졌다. Hammett 식에서도 역시 4-아미노피리딘을 제외하고 logk=-1.33α+0.08 (r=-0 987)의 직선이었다. 이와 같이 4-아미노피리딘의 편차는 용매효과와 공명효과 및 σ 값 그 자체에 기인된다고 생각된다. 이상의 결과로서 본 반응은 전이상태에서 C…N 결합형성에 의하여 반응이 결정되는 SN2 반응메카니즘으로 진행된다는 것을 알았다.

Kinetics of the reaction of phenethyltosylate with substituted pyridines at 50, 60 and 70℃ in acetonitrile were investigated by an electric conductivity method. The effects of substituents on the reaction of phenethyltosylate with pyridines were discussed. The rates of reaction were increased with electron donating power of substituents of pyridines. The isokinetic relationship was shown Eα and ΔS≠, it's temperature was 240。K. Bronsted plots were excellent linear except for 4-amino pyridine given by the following equation, logk=O. 22pKa-3.71 (r=O. 986). According to a plot of log k against Hammett substituent constants, the Iinearity was good except for bamino pyridine too, log k= -1.330+0.08 (r= -0.987). In both cases, deviation of 4-amino pyridine from linearity was considered to solvent effect, resonance effect and 0 value itself. From all the above results, this reaction was found typical SN2 reaction which the rates of reaction was determined by C…N bond formation at transition state.

Page
243 - 247
Full Text
PDF