申请人:Ciba-Geigy Corporation
公开号:US04978768A1
公开(公告)日:1990-12-18
Tetrachloro-2-cyanobenzoic acid alkyl esters of formula ##STR1## wherein R is C.sub.1 -C.sub.5 alkyl, can be very conveniently prepared by (a) reacting the ammonium salt of tetrachloro-2-cyanobenzoic acid, in the presence of water and an inert organic solvent, with a hydroxide of formula MOH, wherein M is Na or K, and removing the ammonia evolved, and (b) reacting the resultant salt of the formula ##STR2## wherein M is as defined above, with at least 1 mole of a dialkyl sulfate of formula SO.sub.2 (OR).sub.2 or an alkyl halide of formula RHal, wherein R is as defined above and Hal is Cl, Br, I or F, also in the presence of water and an inert organic solvent.
式为##STR1##的四氯-2-氰基苯甲酸烷基酯,其中R为C.sub.1-C.sub.5烷基,可以通过以下方法方便地制备:(a)在水和惰性有机溶剂的存在下,将四氯-2-氰基苯甲酸铵盐与式为MOH的氢氧化物反应,其中M为Na或K,并去除放出的氨,(b)在水和惰性有机溶剂的存在下,将所得的式为##STR2##的盐与至少1摩尔的式为SO.sub.2(OR).sub.2的二烷基硫酸酯或式为RHal的烷基卤化物反应,其中R如上所定义,Hal为Cl、Br、I或F。