合成路线1

Intermediate 2-benzylpyridazinone (V) was obtained either by alkylation of dibromopyridazinone (I) with benzyl bromide (II) or by condensation of mucobromic acid (III) with benzylhydrazine (IV). Alkaline hydrolysis of (V) with KOH in HMPA then provided the hydroxy derivative (VI). Further treatment of (VI) with trifluoromethanesulfonic anhydride and Et3N produced sulfonate (VII), which was subsequently coupled with 4-(methylthio)phenylboronic acid (VIII) in the presence of palladium catalyst and Na2CO3. Oxidation of the resulting sulfide (IX) with magnesium monoperphthalate (MMPP) in CH2Cl2 gave the corresponding sulfone (X). Finally, the reaction of (X) with isopropanol in the presence of Cs2CO3 furnished the target isopropyl ether.