合成路线1

4-Bromophenol (I) was acetylated with Ac2O and Et3N, and the resulting 4-bromophenyl acetate (II) was rearranged to 5'-bromo-2'-hydroxyacetophenone (III) in the presence of AlCl3 at 120 C. Subsequent nitration of (III) produced the 3'-nitroacetophenone (IV). The catalytic hydrogenation of the nitro group of (IV), with simultaneous halogen hydrogenolysis, furnished 3'-amino-2'-hydroxyacetophe-none (V). Then, diazotization of the amine group of (V), followed by treatment with KI and Cu powder gave iodide (VI). Coupling of 4-phenyl-1-butanol (VII) with 4-hydroxybenzaldehyde (VIII) under Mitsunobu conditions provided 4-(4-phenylbutoxy)benzaldehyde (IX). Further Wittig reaction of (IX) with methylene triphenylphosphorane (X) gave the styrene (XI). This was condensed with the iodoacetophenone (VI) in the presence of Pd(OAc)2 to produce the stilbene derivative (XII). The benzopyranone (XIII) was prepared by condensation of hydroxyacetophenone (XII) with diethyl oxalate in the presence of NaOEt, followed by acid cyclization. After conversion of the ester function of (XIII) to the corresponding amide with methanolic ammonia, dehydration using POCl3 in DMF afforded nitrile (XIV). The required tetrazole ring was finally obtained by reaction with NaN3 and NH4Cl in DMF at 100 C.