Method for preparing L-pantoprazole sodium

Abstract

The invention discloses a method for preparing L-pantoprazole sodium in an asymmetric oxidation manner. Under the condition that toluene is used as solvent, a chiral coordination compound is generated through pantoprazole thioether under the effect of D-(-)-diethyl tartrate, titanium tetra-isopropoxide and purified water in a brand-new feeding manner; then, the chiral coordination compound is oxidized through an oxidizing agent, namely, p-Dipropylbenzene hydroperoxide, and then L-pantoprazole sodium is prepared; and the high-purity L-pantoprazole sodium can be obtained by conducting one time of refining on the L-pantoprazole sodium and conducting salt formation on the L-pantoprazole sodium and sodium hydroxide. By means of the preparation method, influences of moisture on reaction can be effectively avoided, and therefore the preparation method is suitable for large-batch industrialized production; and by only conducting one time of recrystallization on the L-pantoprazole sodium before and after salt formation, the chromatographic purity and the optical purity of the product can reach 99.5% or above, and the total yield can reach 60% or above. In addition, the preparation method is gentle in reaction condition, small in environment pollution, high in yield and product purity and suitable for industrialized production.

Description

technical field

[0001] The invention relates to the technical field of medicines, in particular to a method for preparing L-pantoprazole sodium. Background technique

[0002] Levopantoprazole Sodium (Levopantoprazole Sodium), chemical name (-)-(S)-5-difluoromethoxy-2-{[(3,4-dimethoxy-2-pyridyl)-methoxy Base]sulfinyl}-1H-benzimidazole sodium was developed and listed by Emcure Company of India in 2006 under the trade name of PanPure. The drug is the S-type optical isomer of pantoprazole sodium. As a new generation of proton pump inhibitors (Proton Pump Inhibitors, PPI), it accurately acts on the core group of H+-K+-ATPase, and has a special The racemic form of pantoprazole sodium and the R-type isomer have a stronger inhibitory effect on gastric acid secretion. In the treatment of gastric damage in various clinical models, patients take L-pantoprazole at a dose of 50% of the racemic form Sodium would have an equivalent effect. This type of drug has a long half-life, does no...

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