合成路线1

Indolinone intermediate (VII): 1. The reductoalkylation of 4-ethoxyaniline (I) with benzaldehyde and NaBH4 in methanol gives the protected aniline (II), which is condensed with methoxymalonyl chloride (III) by means of TEA in dichloromethane to yield the malonamic derivative (IV). The reaction of (IV) with methanesulfonyl azide (V) and TEA affords the diazo compound (VI), which is finally submitted to a decarboxylative cyclization by means of Nafion H (a perfluorinated ion exchange resin) to provide the target indolinone intermediate (VII). 2. The condensation of the protected aniline (II) with diketene (VIII) by means of TEA in THF gives the 3-oxobutyramide (IX), which is treated with methanesulfonyl azide (V) and TEA to yield the diazo compound (X). The deacylation of (X) with KOH in acetonitrile affords the diazoacetamide (XI), which is finally cyclized to the target indolinone intermediate (VII) by means of Rh(OAc)2 in dichloromethane.