合成路线1

2-Methylindole (I) was nitrated employing NaNO3 in H2SO4 and the resultant 5-nitroindole (II) was further reduced to the corresponding indoline (III) by means of NaBH3CN in the presence of HOAc. Catalytic hydrogenation of the nitro group of (III) over Pd/C furnished diamine (IV), which was converted to the bis-carbamate (V) by treatment with benzyl chloroformate. Oxazolidinone (VII) was then obtained by condensation of carbamate (V) with (R)-glycidyl butyrate (VI) in the presence of BuLi at -78 C. After conversion of alcohol (VII) to the corresponding nosylate (VIII), displacement of its sulfonate group with ammonium hydroxide gave rise to the primary amine (IX). Acetylation of amine (IX), followed by hydrogenolysis of the remaining N-benzyloxycarbonyl group, yielded acetamide (X). The indoline N of (X) was then acylated by acetoxyacetyl chloride (XI) to produce amide (XII). The title compound was then obtained by smooth hydrolysis of the acetoxy group of (XII) with K2CO3, followed by separation of the resultant mixture of diastereoisomers by chiral HPLC.