| abstract |
The present invention relates to the preparation method of diclazuril and isotope internal standard D4-diclazuril. The present invention uses 2,6-dichloro-4-nitroaniline as raw material, undergoes Sandmeyer reaction, affinity substitution, Reduction, diazotization, diazonium reduction, two-step condensation reaction, cyclization, and refining to obtain diclazuril or the isotope internal standard D4-diclazuril fine product. In this process, affinity substitution and nitro reduction can be operated continuously without treatment. Diazotization, diazo reduction, and two-step condensation reactions can realize one-pot synthesis. The purity of the preparation can reach 99.5%, and the total yield is higher than that of the original Some processes have been improved by about 10%, and have filled the gap in the field of drug testing. |