A process for the preparation of fungicidally active 3-difluoromethyl-1-methyl-1 H-pyrazole4-carboxylic acid (9-dichloromethylene1,2,3,4-tetrahydro-1,4-methano-naphthalen5ylf-amide

Abstract

The invention relates to “a novel process for the production of 3-difluoromethyl-1 -methyl1H-pyrazole-4-carboxylic acid (9dichloromethylene-1,2,3,4-tetrahydro-1,4methaoo-naphthalen-5-yl)-amide of formula I that makes it possible to prepare said comr pound in high yields and good quality in an economically advantageous way, which process comprises a) reacting a compound of formula II (II), wherein X is chloro or bromo, with an organometallic species in an inert atmosphere to a halobenzyne of formula Xreacting the halobenzyne of formula X so formed with cyclopentadiene to IIIb) reacting III in the presence of an inert solvent with an oxidant to IVc) reacting IV in the presence of a Lewis acid and a hydride source to Vd) reacting V in the presence of an oxidizing agent, a base and an inert solvent to VI e) converting VI in the presence of a triphenyl phosphane and CCI4 or CHCI3 to VII, and f1) reacting VII with NH3. in the presence of a catalyst to the compound of formula VIIIand g) reacting VIII in the presence of a base with a compound of formula IXto the compound of formula I.