A novel synthesis of isocyanates and ureas via β-elimination of haloform

被引：50

作者：

Braverman, S ^{[1
]}

Cherkinsky, M ^{[1
]}

Kedrova, L ^{[1
]}

Reiselman, A ^{[1
]}

机构：

[1] Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel

来源：

TETRAHEDRON LETTERS | 1999年 / 40卷 / 16期

关键词：

isocyanates; ureas; N-monosubstituted trihaloacetamides; beta-elimination of haloform;

D O I：

10.1016/S0040-4039(99)00372-X

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A novel synthesis of isocyanates via base-induced beta-elimination of haloform from N-monosubstituted trihaloacetamides is described. The rate of reaction exhibits a strong dependence on the nature of the trihalomethyl group. Thus, while the reaction of tribromoacetamides proceeds at room temperature and the reaction of trichloroacetamides requires heating in polar solvents, no reaction could be observed for any of the corresponding trifluoro derivatives. This novel beta p-elimination of haloform from stable and readily available trihaloacetamides was applied to a "one-pot" synthesis of ureas which avoids the use of phosgene and isolation of isocyanates. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.

引用

页码：3235 / 3238

页数：4

共 19 条

[1] FLUOROCARBANIONS . RATES OF BASE-CATALYZED HYDROGEN-DEUTERIUM EXCHANGE ISOTOPE EFFECTS + ACIDITY OF MONOHYDROFLUOROCARBONS [J].