A new synthesis of 2-aryloxypropionic acids derivatives via selective mono-c-methylation of methyl aryloxyacetates and aryloxyacetonitriles with dimethyl carbonate
作者:Andrea Bomben、Carlos A. Marques、Maurizio Selva、Pietro Tundo
DOI:10.1016/0040-4020(95)00718-n
日期:1995.10
A one-pot procedure for the mono-C-methylation of methyl aryloxyacetates and aryloxyaceto nitnles by dimethyl carbonate (DMC) is reported The reaction is earned out in an autoclave at high temperatures (180–200 ° C) and in the presence of a base (K2CO3 or bart-BuOK). Although DMC is used either as the alkylating agent or as the solvent (30 molar excess with respect to the substrates). The selectivity
据报道,用碳酸二甲酯(DMC)进行一锅法制得的芳基乙酸甲酯和芳氧基乙酰基甲腈的单C甲基化反应。该反应是在高压釜中于高温(180–200°C)且在有高压釜的情况下完成的。碱(K 2 CO 3或bart -BuOK)。尽管DMC既可以用作烷基化剂也可以用作溶剂(相对于底物30摩尔过量)。在完全转化时,对单甲基化产物(分别为2-芳氧基丙酸甲酯和2-芳氧基丙腈)的选择性通常高达99%。没有二烷基化的副产物形式。这种异常行为的原因可以通过涉及初始羧甲基化然后进行甲基化反应的机理来解释。