Preparation method of optically active N-benzyl phenylephrine

Abstract

The invention discloses a preparation method of optically active N-benzyl phenylephrine, which is shown as a formula 1. The preparation method includes steps that due to alkali assistant and catalysis of chiral diphosphine- chiral diamine transition metal asymmetric hydrogenation catalyst, compound II and hydrogen realize asymmetric hydrogenation in liquor to complete a preparation process, wherein, '*' stands for chiral carbon, namely R or S configuration. The preparation method is high in product yield, higher in both chemical purity and optical purity, low in cost and simple in aftertreatment.

Description

technical field The present invention relates to a synthetic method of optically active N-benzyl-N-methyl-3-hydroxyl-α-phenylethanolamine (N-benzylphenylephrine). Background technique Phenylephrine, also known as phenylephrine, is an adrenaline-mimetic drug, used for prolonging the time of local anesthesia in surgical operations, nasal congestion, acute hypotension, infection toxicity and anaphylactic shock embolism. There is a large demand in clinical practice. N-benzyl-N-methyl-3-hydroxyl-α-phenylethanolamine (N-benzylphenylephrine, compound I) is an important intermediate for the synthesis of phenylephrine. According to prior art document EP1147075, in order to obtain optically active N-benzyl-N-methyl-3-hydroxyl-α-phenylethanolamine, it is necessary to N-benzyl-N-methyl-3-hydroxyl-α-phenylethylamine Ketoamines undergo asymmetric reduction. But the required rhodium catalyst price of this method is more expensive. The optical purity of the obtained product does not m...

AI Technical Summary

Problems solved by technology

The technical problem to be solved by the present invention is to overcome the defects such as high cost, low yield, low optical purity and complicated post-treatment in the preparation method of the existing intermediate N-benzyl phenylephrine for the synthesis of phenylephrine, And provide a kind of preparation method of the N-benzyl phenylephrine of new optical activity