The invention belongs to the technical field of
medicine synthesis, and particularly relates to a preparation method of trimethyl
phloroglucinol. The invention provides a preparation method of trimethyl
phloroglucinol, which comprises the following steps: preparing a crude product: mixing 1, 3, 5-tribromobenzene,
sodium methoxide,
methanol, N, N-
dimethylformamide and
cuprous chloride, uniformly stirring, reacting for 6-12 hours, after the reaction is finished, transferring a reaction solution into a
sulfuric acid solution, crystallizing, and filtering to obtain the trimethyl
phloroglucinol crude product; and crude product purification: adding the trimethyl phloroglucinol crude product and
sodium dithionite into a recrystallization
solvent, heating and stirring to dissolve the trimethyl phloroglucinol crude product and
sodium dithionite, dropwise adding into water to crystallize, and filtering and
drying to obtain trimethyl phloroglucinol. The preparation method provided by the invention has the advantages that the steps are simple, the preparation process is safe and controllable, the yield of the obtained trimethylphloroglucinol is more than 90%, the
liquid phase purity is higher than 99.9%, the color meets the
pharmacopoeia standard requirement, and the industrial
batch production is more favorably realized.