合成路线1

The synthesis of the optical enantiomers of mosapride has been described: The reductocondensation of 4-fluorobenzaldehyde (I) with ethanolamine (II) by means of NaBH4 and NaHCO3 in refluxing methanol gives 2-(4-fluorobenzylamino)ethanol (III), which is condensed with epichlorohydrin (IV) to yield the diol (V). Compound (V), without isolation, is cyclized with conc. H2SO4 to afford 2-(chloromethyl)-4-(4-fluorobenzyl)morpholine (VI), which is treated with refluxing water-formamide to afford the corresponding methanol derivative (VII). Tosylation of (VII) with tosyl chloride and triethylamine/4-(dimethylamino)pyridine in dichloromethane gives the tosylate (VIII) as a racemic mixture. The optical resolution of (VIII) with N-(p-toluenesulfonyl)-L-glutamic acid in methanol affords the (S)-tosylate [(S)-IX] and the (R)-tosylate [(R)-IX]. The reaction of both [(S)-IX] and [(R)-IX] with sodium azide followed by reduction with bis(2-methoxyethoxy)aluminum hydride (vitride) gives the chiral amines [(S)-X] and [(R)-X], which are finally condensed with 4-amino-5-chloro-2-ethoxybenzoic acid (XI) by means of 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide (WSC) in dichloromethane, yielding the (S)- and (R)-enantiomers of mosapride.