Patent ID: 7678923

Claim:
A method for synthesizing 5-chloro-1-aryl-4-(4,5 -dicyano- 1H-imidazol -2-yl)-3-alkyl-1H-pyrazol compounds of the formula (I): wherein: R 1 to R 5 , which are identical or different, each represent a group selected from the group consisting of: a hydrogen atom, a halogen atom, and a radical corresponding to the formula -(X)n-R 7 , in which X represents a group selected from the group consisting of oxygen, sulfur, sulfinyl radical and sulfonyl radical; n is 0 or 1; and R 7 represents a linear or branched, saturated or unsaturated alkyl radical optionally substituted with one or more halogen atoms, which are identical or different, the alkyl radical comprising 1 to 4 carbon atoms; R 6 represents a linear or branched, saturated or unsaturated alkyl radical comprising from 1 to 6 carbon atoms, optionally substituted with one or more halogen atoms, which are identical or different, which method comprises the steps of: (a) converting a pyrazolin-5-one compound of the formula (II) to a 1-aryl-3-alkyl-4-carboxaldehyde-5-chloropyrazol compound of the formula (IV) in one step by a Vilsmeier treatment in the presence of POCl 3 and DMF, (b) converting the aldehyde of the formula (IV) to a 1-aryl-3-alkyl-4-[(2-amino-1,2-dicyanoethenylimino)methyl]-5-chloropyrazole compound of the formula (V) by condensing the aldehyde of the formula (IV) with diaminomaleonitrile, and (c) oxidatively cyclizing the imine of the formula (V) with a hypochiorite to produce the compound of the formula I as shown below: