Electronic and Steric Effects of Alkyl Group on Denitrosation of 3-Alkyl-1-methyl-1-nitrosothioureas
作者:Masayoshi Isobe
DOI:10.1246/bcsj.58.2844
日期:1985.10
According to rate measurements in CH3COOD–D2O, the kinetic isotope effect kH:kD is 1.25 for 4. Except 3, a linear plot of logkR⁄kMe for the denitrosation of RNHCSN(NO)CH3 vs. σ* provides ρ*=−0.98 (r=−0.997). The significant factor affecting the rate-determining step of the denitrosation of these N-nitrosothioureas at pH 4.6 is the electronic effect of the substituent at the N3 position.
合成了一系列具有 R=CH3、C2H5、环-C6H11(3)、(CH3)2CH(4)、C2H5(CH3)CH 和 (CH3)3C 的 3-烷基-1-甲基-1-亚硝基硫脲,并他们测量了酸催化(pH<6.5)脱硝的速率。根据 CH3COOD–D2O 中的速率测量,对于 4,动力学同位素效应 kH:kD 为 1.25。除了 3,RNHCSN(NO)CH3 与 σ* 脱硝的 logkR⁄kMe 线性图提供 ρ*=−0.98 (r=-0.997)。影响这些 N-亚硝基硫脲在 pH 4.6 下脱亚硝化的速率决定步骤的重要因素是 N3 位取代基的电子效应。