METHOD OF SYNTHESIS OF α-ISOMER OF 2,5-DIMETHYL-4-HYDROXYPIPERIDINE AS SEMIPRODUCT IN PRODUCTION OF TOPICAL ANESTHETIC RICHLOCAINE Russian patent published in 2000 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method of synthesis of α--isomer of 2,5-dimethyl-4-hydroxypiperidine as semiproduct used in production of local anesthetic preparation richlocaine. Method involves reduction of 2,5-dimethyl-4-ketopiperidine with boron hydride sodium in the presence of mineral acid at pH value of solution at the range 4.5-6.0 and at temperature of reaction mixture 0-5 C. Carrying out the process in the presence of mineral acids increases stereoselectivity of process and yield of α--isomer up to 96%. EFFECT: improved method of synthesis. 1 tbl