合成路线1

Intramolecular Diels-Alder reaction of the N-pyrazinylmethyl-N-propargyl carbamate (I), with subsequent extrusion of HCN, gave rise to a mixture of the isomeric pyrrolopyridines (II) and (III). Acidic hydrolysis of the pyrrolo[3,4-b]pyridine carbamate (III) provided the bicyclic amine (IV). This was condensed with 3,4-difluoronitrobenzene (V) to give the aryl amine (VI). Catalytic hydrogenation of the nitro group of (VI) yielded aniline (VII), which was converted to the benzyl carbamate (VIII) upon treatment with benzyl chloroformate. The chiral oxazolidinone (X) was then obtained by condensation of the lithium salt of carbamate (VIII) with (R)-glycidyl butyrate (IX) at -78 C. Conversion of alcohol (X) to mesylate (XI), and subsequent mesylate displacement with NaN3 in hot DMF, furnished azide (XII). Finally, hydrogenation of azide (XII) to the corresponding amine, followed by acylation with Ac2O, led to the target acetamide.