合成路线1

3,4,5-Trimethoxyphenylacetic acid (IX) was alkylated with ethyl iodide in the presence of two equivalents of sodium bis(trimethylsilyl)amide to afford racemic trimethoxyphenylbutyric acid (X). After conversion to the corresponding acid chloride with SOCl2, condensation with (R)-4-benzyl-2-oxazolidinone (XI) in the presence of n-butyllithium gave N-acyloxazolidinone (XII) as a diastereomeric mixture that was separated by column chromatography. The required diastereoisomer was then hydrolyzed with lithium peroxide to provide (S)-2-(3,4,5-trimethoxyphenyl)butyric acid (XIII). Subsequent coupling of (XIII) with methyl (S)-pipecolate (XIV) employing 2-chloro-1-methylpyridinium iodide, followed by ester hydrolysis with LiOH, provided amide (XV). Further DCC-promoted coupling of (XV) to alcohol (VIII) provided (XVI). After acid cleavage of the tert-butyl ester, the resulting carboxylic acid was finally coupled to etylenediamine (XVII) in the presence of 1-benzotriazolyloxy tris(dimethylamino)phosphonium hexafluorophosphate to yield the title compound.