合成路线1

Hydrogenation of 2,3-dichloronitrobenzene (I) with H2 over Ra-Ni in methanol gives 2,3-dichloroaniline (II), which is diazotized with NaNO2 and HCl and treated with CuCN to yield 2,3-dichlorobenzonitrile (III). Hydrolysis of the nitrile (III) with NaOH in refluxing methanol/water affords 2,3-dichlorobenzoic acid (IV), which is treated with hot SOCl2 to provide the corresponding acyl chloride (V). Reaction of (V) with CuCN and KI in refluxing chlorobenzene gives 2,3-dichlorobenzoyl cyanide (VI), which is condensed with aminoguanidine (VII) by means of H2SO4/TsOH in hot toluene to yield 2,3-dichlorobenzoyl cyanide amidinohydrazone (VIII). Finally, this compound is cyclized by treatment with NaOMe in refluxing methanol.