杀虫剂溴虫腈的合成

Synthesis of insecticide chlorfenapyr

以α 对氯苯基甘氨酸为起始原料 ,经与三氟醋酐的同步酰化环合 ,然后与 2 氯丙烯腈的 1,3 偶极环化加成 ,合成重要中间体 2 (对氯苯基 ) 5 (三氟甲基 )吡咯 3 腈 ;在缚酸剂存在下进行芳基吡咯的环上溴化 ,然后在有机碱存在下与二溴甲烷和乙醇钠同时进行N 溴甲基化和醚化 ,得到芳基吡咯类杀虫剂溴虫腈。其总收率达 6 9% ,含量 95 %左右。缚酸剂的使用显著改善了芳基吡咯腈的溴化过程 ,大大缩短了反应时间。

The synthesis of chlorfenapyr was achieved by starting from α-(p-chlorophenyl)glycine.The glycine reacted with trifluoromethyl acetic anhydride,and further with 2-chloroacrylonitrile,giving the intermediate 2-(p-chlorophenyl)-5-(trifluoromethyl)pyrrole-3-carbonitrile.The intermediate went through bromination at pyrrole in the presence of a base,and the resulting bromide was then subjected to ethoxymethylation by reaction with CH 2Br 2 and C 2H 5ONa.The total yield is 69% of theoretical.The purity of chlorfenapyr is about 95%.The bromination of the arylpyrrolecarbonitrile was significantly improved by employing a base,leading to a good yield while taking short reaction time.