17710-62-2Relevant articles and documents
Aminolysis of aryl chlorothionoformates with anilines in acetonitrile: Effects of amine nature and solvent on the mechanism
Oh, Hyuck Keun,Ha, Joo Suk,Sung, Dae Dong,Lee, Ikchoon
, p. 8219 - 8223 (2007/10/03)
The aminolysis of aryl chlorothionoformates (7, YC6H 4OC(=S)Cl) with anilines (XC6H4NH2) in acetonitrile at 5.0 °C has been investigated. The rates are slower than those for the corresponding reactions of aryl chloroformates (6, YC 6H4OC(=O)Cl). This rate sequence is a reverse of that for alkyl chloroformates (1 4) in water, for which rate-limiting formation of a tetrahedral intermediate, T±, is predicted. On the basis of the large negative cross-interaction constant, ρXY = -0.77, failure of the reactivity-selectivity principle, normal kH/k D values involving deuterated nucleophiles (XC6H 4ND2), and low ΔH≠ with large negative ΔS≠ values, a concerted mechanism with a four-membered hydrogen bonded cyclic transition state (11) is proposed for the title reaction series. It has been shown that the solvent change from water to acetonitrile for the aminolysis of 6 and 7 causes a mechanistic change from stepwise to concerted.
