Synthesis Of D-rabeprazole Sodium

The chemical name of R-(+)-rabeprazol sodium salt is R-(+)2-[[[4-(3-methoxypropoxy)-3-methy-2-pyridinyl]methy1] sulfiny1]-1H-Ben zimidazole sodium salt,which is the single isomeride of the rabepraz ol.Compared to its racemic modification and (-)rabeprazol,(+)-rabep razol have better selectivity,higher bioavialbility,longer half-life,better plasma protein binding rate and lower toxic side effect.This study use2,3-dimethylpyridine as row material,through oxi dation, nitrification, chlorination, rearrangement, hydrolyzation, Substit ution reaction to obtain of the2-chloromethyl-3-metllyl-4-[(3-metllox y)propoxy]-pyridine hydrocmoride.Further visa condensation reaction with2-mercapto-lH-benzimidazole react to obtain of rabeprazole inte rmediates:2-[[4-(3-methoxypropoxy)-3-methy-2-pyridinyl]methy1thio]-1H-Benzimidazole.Then the R-(+)-2-[[[4-(3-methoxypropoxy)-3-methy-2-pyridinyl]methy1]sulfiny1]-1H-Benzimidazole was synthesized from L-(+)-diethyl tartrate as the chiral reagent and titanium(iv)isopropo xide as the center of the ligand and cumene hydroperoxide as the oxidizing agent by asymmetric oxidation,then get the R-(+)-rabepraz ole sodium through the condensation reaction between R-(+)-2-[[[4-(3-methoxypropoxy)-3-methy-2-pyridinyl] methy1] sulfiny1]-1H-benzimi dazole and sodium hydroxide. Meanwhile synthesis technology incul ed hydrogen peroxide oxidation, rearrangement reaction, hydroxylatio n, condensation was analyzed, especially the asymmetric oxidation of the2-[[4-(3-methoxypropoxy)-3-methy-2-pyridinyl]methy1thio]-1H-Benzimidazole,which is the critical step of the synthesis technology made detailed study and it acquire optimized process.Products detected by HPLC more than99.8%purity, isomer con tent below0.1%; structure combined with the synthesis process, HP LC profiles, liquid-qualitative,1HNMR confirmation. The process of raw material is homebred change, suitable for the industrialized pro duction requirement.