Patent ID: 8217179

Claim:
A preparation method of phenylcarboxamides as represented by formula (I), the reaction scheme is as follows: wherein: R 1 is halogen, CN or CH 3 ; R 2 is halogen or CN; R 3 is H or C 1 -C 3 alkyl; R 4 is H, C 1 -C 6 alkyl or C 3 -C 6 cycloalkyl; R 5 is C 1 -C 10 alkyl, benzyl or C 3 -C 5 alkenyl; X and Y are selected independently Cl or Br; the reaction steps are as follows: 1) hydrolysis reaction: the 3-halo-1-(3-chloro-2-pyridyl)-4,5-dihydro-1H-pyrazole-5-carboxylate (V) is added into 10 to 500 times moles solvent of water, the mixture of water and alcohol, or the mixture of water and ether, then add 0.8 to 2 times moles of base, at a temperature from −10° C. to boiling point for 0.5 to 48 hours; the carboxylic acid salt is formed, and then acidified to form the 3-halo-1-(3-chloro-2-pyridyl)-4,5-dihydro-1H-pyrazole-5-carboxylic acid of formula (IV); when using the mixture of water and alcohol, or water and ether as solvent, the volume ratio of water to alcohol, or water to ether is 1:0.1-10; 2) acyl halogenation and oxidation reaction: the carboxylic acid of formula (IV) react with 1 to 20 times moles acyl halide reagents in the appropriate solvent to obtain the 3-halo-1-(3-chloro-2-pyridyl)-1H-pyrazole-5-carbonyl halide of formula (III) at a temperature between −10° C. and boiling point for 0.5 to 48 hours for the acyl halogenation and oxidation reaction; the acyl halide reagent is selected from the group consisting of thionyl chloride, phosphorus trichloride, phosphorus tribromide, phosphorus pentachloride or phosphorus pentabromide; the solvent is selected from the group consisting of benzene, toluene, acetonitrile, dioxane, hexane or liquid acyl halide reagents, and the amount of solvent is 5 to 500 times moles larger than that of the acid of formula (IV); 3) condensation reaction: the acyl halide of formula (III) reacts with aniline (II), the molar ratio of which is 1:0.8-1.2, without the presence of acid binding agent in the appropriate solvent to obtain the phenylcarboxamide of formula (I) at a temperature between −10° C. and boiling point for 1 to 10 hours; the solvent is selected from the group consisting of dichloromethane, chloroform, carbon tetrachloride, hexane, benzene, toluene, ethyl acetate, acetonitrile, tetrahydrofuran, dioxane, acetone, butanone or dimethyl sulfoxide, and the amount of solvent is 5 to 500 times moles larger than that of acyl halide of formula (III).