Current time in Korea 15:02 Mar 07 (Sun) Year 2021 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 21, Number 1
JKCSEZ 21(1)
February 20, 1977 

Kinetics of the Reaction of Substituted Pyridines with Benzyl Benzenesulfonate (Ⅴ)

Benzyl Benzenesulfonate 와 치환피리딘류의 반응에 관한 반응속도론적 연구 (제5보).
Woo Bung Lee, Soo Dong Yoh, Soon Yung Hong

이우붕, 여효동, 홍순영
Benzyl benzenesulfonate와 3- 또는 4-치환피리딘의 반응속도를 아세톤 용매중, 35℃에서 전기 전도도법으로 측정하였다. Benzyl benzenesulfonate와 피리딘의 Sn2반응에서 Hammett 치환기 상수와 log k를 도시하면 반응속도는 치환기의 전자를 주는 능력이 클 수록 증가하였고 4-NH2 피리딘은 Hammett의 σ값보다 σ+로 잘 상관지어졌다. 이 결과는 NH2기 σ와 피리딘 고리안의 N원자와 공명의 기여가 큼을 나타낸다. Bronsted 도시에서 4-NH2와 전자를 당기는 기는 직선에서 반응이 큰쪽으로 벗어 났으며 이는 치환기에 대한 용매효과에 기인된다고 생각된다.

The rate constant of the reaction of 3-or 4-substituted pyridines with benzyl benzenesulfonate in acetone at 35℃ were determined by an electric conductivity method. According to the Hammett plot, the rates were increased the electron donating ability at the SN2 reaction of benzyl benzenesulfonate with pyridine and 4-NH2 pyridine was correlated with σ+ than Hammett σ value. This result was explained that NH2 group and N atom in pyridine are largely contribute by resonance. In Bronsted plot, 4-amino and electron attracting group were deviated from the increasing part at linearity. It was considered to solvent effects on substituents. A mechanistic possibility was proposed to account for the results. Some activation parameters were also calculated.

38 - 43
Full Text