METHOD OF CONTINUOUS SYNTHESIS OF PHARMACEUTICAL INTERMEDIATE Russian patent published in 2023 - IPC C07C45/68 C07C49/323 C07C49/35 

FIELD: pharmaceuticals.

SUBSTANCE: invention relates to a method of the continuous synthesis of the compound of formula (III)

which is a pharmaceutical intermediate. The proposed method includes the following: before the continuous photochemical reaction, mixing raw material A with a solvent to form a mixed solution, and then supplying the mixed solution to a continuous reaction apparatus, wherein the solvent is one or more solvents selected from the group consisting of n-hexane, n- heptane, n-butyl ether, cyclohexane and cyclopentane; continuously supplying raw material A and raw material B to the continuous reaction device for continuous photochemical reaction under irradiation with a light source to produce a compound of formula (III); and controlling the reaction temperature in the continuous reaction device with a temperature controller during the reaction. Here, raw material A has a structure represented by formula (I), and raw material B has a structure represented by formula (II):

in formula (I) R¹ and R² are each independently selected from hydrogen, benzyl, methyl, phenyl, halogen, ester group, carboxyl or hydroxy, R³ is selected from hydrogen, benzyl, methyl, phenyl, halogen, ester group, carboxyl or hydroxy, or alternatively R³ is selected from p-methoxybenzyl, p-methoxyphenyl, when R¹, R² are hydrogen and at least one of R¹, R² and R³ is not hydrogen;

in formula (II) R⁴ and R⁵ are selected from methyl. The reaction temperature of continuous photochemical reaction is 0–5°C, the reaction time of a continuous photochemical reaction is 10–20 min.

EFFECT: production of a compound of formula (III) while improving the conversion rate.

6 cl, 1 dwg, 12 ex