合成路线1

The condensation of tetrahydropyran-4-carbonyl chloride (V) with refluxing 1,3-difluorobenzene (VI) by means of AlCl3 gives 1-(2,4-difluorophenyl)-1-(tetrahydropyran-4-yl)methanone (VII), which is treated with hydroxylamine hydrochloride and sodium acetate in refluxing ethanol/water to yield the corresponding oxime (VIII). The cyclization of (VIII) by means of KOH in refluxing methanol affords 6-fluoro-3-(tetrahydropyran-4-yl)-1,2-benzisoxazole (IX), which is treated with NaI and Ac-Cl and then with K2CO3 in refluxing acetonitrile to provide the 5-iodopentanol derivative (X). The reaction of the OH group of (X) with Ms-Cl and TEA in dichloromethane gives the corresponding mesylate (XI), which is finally cyclized with the intermediate amine (IV) by means of NaHCO3 in refluxing acetonitrile to yield the target piperidine.