合成路线1

Reduction of 3-(4-fluorobenzoyl)propionic acid (I) by means of AlCl3 in CH2Cl2 and borane/tert-butylamine complex yields alcohol (II), which is then converted into aldehyde (IV) by reaction with 4-hydroxybenzaldehyde (III) in presence of PPh3 in THF and diethyl azodicarboxylate. Treatment of (IV) with a solution of methyltriphenylphosphonium bromide in THF and a solution of n-BuLi in hexane affords styrene derivative (V), which couples with 2’-hydroxy-3’-iodoacetophenone (VI) in presence of Et3N and Pd(OAc)2 in CH3CN to provide (VII). Cyclization of (VII) by means of a first treatment with NaOEt in EtOH followed by reaction with diethyl oxalate in Et2O/EtOH yields benzopyrane derivative (VIII) which is then hydrolyzed with NaOH in THF/MeOH to give (IX). Carboxylic acid (IX) is first converted into carboxamide (X) by treatment with a saturated NH3 solution in MeOH and then into carbonitrile (XI) by means of POCl3 in DMF. Finally, treatment of (XI) with a solution of NaN3, NH4Cl and DMF leads to the formation of the desired product.