合成路线1

Condensation of 3,4,5-trichloro nitrobenzene (I) with 4-chlorobenzeneacetonitrile (II) by means of NaOH and N,N,N-triethylbenzylammonium chloride in THF yields substituted nitrobenzeneacetonitrile (III), which is subjected to hydrogenation over Pt/C in MeOH in the presence of thiophene to provide aniline (IV). Treatment of (IV) with HCl, HOAc and NaNO2, followed by reaction with ethyl N-(2-cyanoacetyl) carbamate (V) in AcOEt, furnishes ethyl carbamate derivative (VI), which is then subjected to cyclization by means of KOAc in refluxing HOAc to yield perhydro-3,5-dioxo-1,2,4-triazine derivative (VII). Hydrolysis of the nitrile moiety of (VII) by treatment with HCl in refluxing HOAc gives carboxylic acid (VIII), which is finally decarboxylated by heating in 2-mercaptoacetic acid to provide the desired product.