合成路线1

The precursor acid chloride (VII) was synthesized from isophthalic acid (I) as follows: Treatment of the triethylammonium salt of (I) with benzyl bromide provided the mono-benzyl ester (II). Acid chloride (III) was then formed by reaction of (II) with oxalyl chloride in the presence of a catalytic amount of DMF. Arndt-Eistert homologation of (III) to produce (VI) was achieved via reaction with diazomethane to yield the intermediate diazo ketone (IV). Wolff rearrangement of diazo ketone (IV) in the presence of Ag2O in hot trichloroethanol furnished the trichloroethyl ester (V). Reductive cleavage of the trichloroethyl ester group of (V) with Zn and HOAc then gave the carboxylic acid (VI). This was subsequently activated as the acid chloride (VII) by using oxalyl chloride and DMF.