申请人:Imperial Chemical Industries Limited
公开号:US04310464A1
公开(公告)日:1982-01-12
4-.beta., .beta.-dichlorovinyl (or dibromovinyl)-3,3-dimethylbutyrolactones are prepared from 1,1-dichloro (or dibromo)-4-methylpenta-1,3-diene by reacting with an acid of formula CH.sub.2 R.CO.sub.2 H in presence of a salt of a metal in one of its higher valency states, especially manganese (III), cerium (IV), or vanadium (V). Higher yields are obtained in the presence of the anhydride of the acid and of the sodium or potassium salt of the acid. Treatment of the lactones with an inorganic acid halide opens the lactone ring with formation of the corresponding 4-haloacid halide, which with alcohols affords the corresponding 4-haloacid ester, cyclised by bases to a 3-.beta.,.beta.-dichloro (or dibromo)vinyl-2,2-dimethylcyclopropanecarboxylic ester, intermediate for insecticides such as the m-phenoxybenzyl ester.
4-.beta.,.beta.-二氯乙烯基(或二溴乙烯基)-3,3-二甲基丁酰内酯是由1,1-二氯(或二溴)-4-甲基戊-1,3-二烯与一个公式为CH.sub.2 R.CO.sub.2 H的酸在一种金属的高价态盐的存在下反应制备而成的,特别是锰(III),铈(IV)或钒(V)。在酸酐和酸的钠或钾盐的存在下,可以获得更高的产量。将内酯与无机酸卤素处理,打开内酯环,形成相应的4-卤代酸卤化物,与醇反应,得到相应的4-卤代酸酯,经过碱的环化,得到3-.beta.,.beta.-二氯乙烯基(或二溴乙烯基)-2,2-二甲基环丙烷羧酸酯,是杀虫剂如m-苯氧基苯甲酸酯的中间体。