A process for the preparation of fungicidally active 3-difluoromethyl-1 -methyl-1 H-pyrazole4-carboxylic acid (9-dichloromethylene- " 1,2,3,4-tetrahydro-1,4-methano-naphthalen5-yl)-amide

Abstract

The invention relates to a novel process for the production of 3-difluoromethyl-1-methyl1H-pyrazole-4-carboxylic acid (9-dichloromethylene-1,2,3,4-tetrahydro-1,4-methanonaphthalen-5-yl)-amide of formula Ithat makes it possible to prepare said compound in high yields and good quality' in an economically advantageous way, which process comprises a) reacting a compound of formula II (11), 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 III b) 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, andf2) reacting the compound of formula VIIin the presence of a solvent, a base, a copper catalyst and at least one ligand with the compound of formula IXato the compound of formula I.