| abstract |
1. The method of obtaining esters of 5-aminolevulinic acid hydrochloride of high purity,nby converting 5-aminolevulinic acid hydrochloride to an ester by reaction with an alcoholnand thionyl chloride, characterized in that the hydrochloride of 5-aminolevulinic acid is subjected to a knownnby reaction with alcohol and thionyl chloride, and the obtained ester is mixed with a polar solventnaprotic and left to recrystallize at a temperature of up to 30 ° C, possibly with stirring,nthe precipitate is then separated and dried. |