Synthesis of 2- (3,4,5-Trichlorophenyl) -1,2,4-triazine-3,5 (2H,4H) -dione

2-(3,4,5-Trichlorophenyl)-l,2,4-triazine-3,5(2H,4H)-dione was synthesized from 2,6-dichloro- 4-nitroaniline by diazotization,chlorination and reduction to give 3,4,5-trichloroaniline,which was subjected to diazotization and coupling with N,N'-bis(ethoxycarbonyl) malonamide,cyclization,hydrolysis and then decarboxylation with an overall yield of about 39%(based on 2,6-dichloro-4-nitroaniline).