Mechanochemical Preparation of Hydantoins from Amino Esters: Application to the Synthesis of the Antiepileptic Drug Phenytoin
作者:Laure Konnert、Benjamin Reneaud、Renata Marcia de Figueiredo、Jean-Marc Campagne、Frédéric Lamaty、Jean Martinez、Evelina Colacino
DOI:10.1021/jo5017629
日期:2014.11.7
eco-friendly preparation of 5- and 5,5-disubstituted hydantoins from various amino ester hydrochlorides and potassium cyanate in a planetary ball-mill is described. The one-pot/two-step protocol consisted in the formation of ureido ester intermediates, followed by a base-catalyzed cyclization to hydantoins. This easy-handling mechanochemical methodology was applied to a large variety of α- and β-amino esters
New derivatives of 2-(1-amino-1-phenylmethyl)-1,3,4-oxadiazole and 1,2,4-triazin-6-one were synthesised in the reactions of opticallyactive α-aminocarboxylic acid hydrazides and triethyl orthoesters in xylene. The electronic and steric effects of substituents at the α position influencing the formation of five- or six-membered products are discussed.
Cyclopalladation and Reactivity of Amino Esters through CH Bond Activation: Experimental, Kinetic, and Density Functional Theory Mechanistic Studies
作者:Eduardo Laga、Angel García‐Montero、Francisco J. Sayago、Tatiana Soler、Salvador Moncho、Carlos Cativiela、Manuel Martínez、Esteban P. Urriolabeitia
DOI:10.1002/chem.201302693
日期:2013.12.16
orthopalladation, throughCHbondactivation, of a large number of amino esters and amino phosphonates derived from phenylglycine, and having different substituents at the aryl ring and the C‐α atom, as well as on the N‐amine atom, has been studied. The experimental observations indicated an improvement in the yields of the orthopalladated compounds when the N‐amine and/or the C‐α atom are substituted