p-Substituted 1-chloro-3-phenyldiazirines (5), the putative intermediates of the reaction of N,N,N'-trichlorobenzamidines (10) with excess of bromide ions, react further to afford mixtures of 3-bromo- (4) and 3-chloro-3-phenyldiazirines (6). The 6:4 ratios inversely correlate with the Hammett σp and σp+ constants of the p-substituents. The formation of 4, proposed to proceed by anti-SN2‘ mechanism
对位取代的1-氯-3-苯基重氮(5)是N,N,N'-三氯苯甲m(10)与过量溴离子反应的推定中间体,进一步反应生成3-溴-(4)和3-氯-3-苯基重氮(6)。该6:4的比率用哈米特σ负相关p和σ p +的常数p -取代基。4的形成,建议通过反S N进行2'机理主要是吸电子的p-取代基。化合物6是具有给电子性p取代基的主要产物,它可以由5通过极性过渡结构12进行氯的[1,3]-σ位移而从5中产生。气相DFT(B3LYP / 6-31 + G *)对这两种机理的研究结果与实验一致。
<i>N</i>-Halogen Compounds of Cyanamide Derivatives. VI. The Preparation and Reaction of 2-Carbonimidoyl-3-imino-<i>Δ</i><sup>4</sup>-1,2,4-thiadiazolines
作者:Toshio Fuchigami、Keijiro Odo
DOI:10.1246/bcsj.49.3165
日期:1976.11
The reactions of potassium methyl cyanoiminodithiocarbonate (I), potassium methoxy and ethoxythiocarbonylcyanamide (IIa and IIb) with N-chloroamidines in various solvents were investigated. Δ4,2,4-Thiadiazolines (TDZ), IIIa–d, were obtained from I in good yields, whereas the 1,3,5-triazines obtained as by-products in addition to TDZ were formed from II and N-chlorobenzamidine (NCB) in chloroform and