However, we only gained a mixture of products, possibly due to the nucleophilic nature of the deprotonated aromatic carboxylic acid . Repeating the experiment with aniline-2-sulfonic acid yielded macrocycle 2 (47%; see Figures in the Supplementary Information). Since straightforward substitution of 1 failed, we attempted to prepare 6 indirectly. Reaction of 1 with 2-bromoaniline produced bromide 3, which is already known in literature . Our protocol enhanced the known yield from 63% to 85%. We converted bromide 3 to aromatic aldehyde 4 by lithiation and in-situ reaction with DMF (64% yield; see Figures in the Supplementary Information). We then attempted to oxidize the aldehyde with KMnO 4 , but could not gain the desired product.