Kinetics of solvolysis of 1‐acetyl‐4‐(1‐ethoxycarbonyl‐1‐cyano) methylene‐1,4‐dihydroquinoline in undried DMSO‐d6· formation of Acetic Anhydride as an intermediate

Abstract

AbstractThe kinetics of solvolysis of the title compound (QAc) in undried DMSO‐d6 to give 4‐(1‐ethoxycarbonyl‐1‐cyano)methylquinoline (QH) and HOAc at ambient temperature were investigated by 1H nmr spectrometry. With a limited excess of water the solvolysis follows a three‐step process of \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm QAc} + {\rm H}_2 {\rm O}\mathop \to \limits^{k_1} {\rm QH} + {\rm HOAc}, $\end{document} , and \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm Ac}_{\rm 2} {\rm O} + {\rm H}_2 {\rm O}\mathop \to \limits^{k_3} {\rm 2\,HOAc}, $\end{document} where k2 > k1 and k3 < k1. Addition of pyridine‐d5 to the reaction mixture markedly catalyzes the overall solvolysis, while addition of CF3CO2D to the reaction mixture simplifies the kinetics to pseudo first‐order in [QAc] with k = 4.3 × 10−3 min−1.