The present invention provides an improved process for preparation of L-threo-(2S,3R)-3-(3.4- dihydroxyphenyl)serine (I) (Droxidopa) and its salts; comprising (a) reaction of the aldehyde compound (III) (as described herein) with Metal complex (II) (as described herein), and (b) hydrolysis of the compound (IV) obtained from step (a) in presence of acid. The present invention also relates to a novel intermediates metal chiral complex (IV) for the preparation of Droxidopa.
本发明提供了一种改进的L-threo-(2S,3R)-3-(3.4-二羟基
苯基)
丝氨酸(I)(Droxidopa)及其盐的制备方法,包括(a)将醛化合物(III)(如本文所述)与
金属配合物(II)(如本文所述)反应,以及(b)在酸存在下
水解步骤(a)所得化合物(IV)。本发明还涉及一种新的
中间体金属手性配合物(IV),用于制备Droxidopa。