In another attempt, we used methyl anthranilic ester as a nucleophile and obtained methyl ester 5 in 33% yield (see Figures S7-S8 in the Supplementary Information). Following a saponification procedure for arylic esters , we hydrolyzed methyl ester 5 under mild conditions with sodium hydroxide and gained the free acid target compound 6 within four hours in a yield of 94% (see Figures S9-S12 in the Supplementary Information).