Journal of the Korean Industrial and Engineering Chemistry, Vol.14, No.7, 994-997, November, 2003
Pyrazinium Chlorochromate를 이용한 알코올류의 산화반응과 반응속도에 관한 연구
A Study for Kinetics and Oxidation Reaction of Alcohols using Pyrazinium Chlorochromate
E-mail:
초록
6 M-HCl 용액 용매하에서 피라진과 chromium (VI) trioxide에 의한 pyrazinium chlorochromate (PyzCc)를 합성하여, IR, EA 및 ICP 등으로 구조를 확인하였다. 산 촉매를 이용한 N,N-디메틸포름아미드 용매하에서 PyzCc는 벤질알코올과 그의 유도체(p-CH3, H, m-Br, m-NO2)들을 효과적으로 산화시켰다. 본 실험에서 전자받게 그룹들은 반응속도가 감소한 반면에 전자주게 치환체들은 반응속도를 증가시켰다. 또한 Hammett 반응상수 ρ값은 -0.68 (308 K)이였다. 그러므로 PyzCc를 이용한 알코올의 산화반응 과정은 먼저 크토메이트 에스테르 형성과정을 거친 후, 속도결정단계에서 양성자 전이가 일어나는 메카니즘을 알 수 있었다.
Pyrazinium chlorochromate (PyzCc) was synthesized by the reaction of pyrazine with chromium (VI) trioxide in 6 M HCl. PyzCc structure was verified by IR, EA and ICP. In the presence of hydrochloric acid (HCl), PyzCc oxidized benzyl alcohol and its derivatives (p-CH3, H, m-Br, m-NO2) smoothly in N,N-dimethylformamide solvent. Electron-donating substituents accelerated the reaction, whereas electron-withdrawing groups retarded the reaction. The hammett reaction constant, ρ was -0.68 at 303 K. The observed experimental data have been ratiolized as follows; the proton transfer occurs after the prior formation of a chromate ester in the rate-determining step.
Keywords:dielectric constant;substituted benzyl alcohol;Hammett reaction constant ρ;proton transfer;chromate ester
- Banerji KK, Ind. J. Chem., 17A, 300 (1979)
- Banerji KK, Bull. Chem. Soc. Jpn., 61, 1767 (1988)
- Kuo JF, Bull. Chem. Soc. Jpn., 64, 3059 (1991)
- Mahanti MK, Dey D, J. Org. Chem., 55, 5848 (1990)
- Mahanti MK, Bull. Korean Chem. Soc., 4, 120 (1983)
- Panigrahi GP, Bull. Korean Chem. Soc., 13, 547 (1992)
- Mahanti MK, Kuotsu B, Tiewsoh E, J. Org. Chem., 61, 8875 (1996)
- Davis HB, Sheets RM, Pandler WW, Heterocycles, 22, 2029 (1984)
- Pressprich MR, Willett RD, Davis HB, Inorg. Chem., 27, 260 (1988)
- Cho MH, Kim JH, Park HB, J. Korean Chem. Soc., 33, 366 (1989)
- Yadav GD, Haldavanekar BV, J. Phys. Chem. A, 101(1), 36 (1997)