The base-catalysed cyclisation of phenyl N-(2-hydroxybenzyl)-N-methylcarbamates is concerted
作者:Vojeslav Štěrba、Oldřich Hrabík、Jaromír Kaválek、Jaromír Mindl、Andrew Williams
DOI:10.1039/b209323p
日期:2003.1.13
The kinetics of the cyclisation in aqueous solution of phenyl-(2-hydroxybenzyl)-N-methylcarbamates to 3-methyl- 3,4-dihydrobenzo[e][1,3]oxazin-2-ones and phenolate ions fit the rate law: kobs = kc/(1 + [H3O+]/Ka) The values of kc and pKa fit Brønsted equations against the pKa's of the corresponding free phenols but the system does not conform to the reactivity-selectivity hypothesis. The values of
Thirteen previously unreported substituted phenyl N-(2-hydroxybenzyl)-Nmethylcarbamates were prepared by the reaction of substituted 2-hydroxybenzyl-Nmethylamines with phenyl chlorocarbonates. They were identified by their 1H- and 13C-NMR spectra.