Synthesis of lipophilic lariat ethers with pendant N‐(X)sulfonyl carboxamide groups

Synthetic routes to sixteen lipophilic lariat ether N‐(X)sulfonyl carboxamides with X = trifluoromethyl, methyl, phenyl, and p‐nitrophenyl are described. For this new family of proton‐ionizable lariat ethers in which the acidity can be ‘tuned’ by X group variation, the ring size is systematically varied from 12‐crown‐4 to 14‐crown‐4 to 15‐crown‐5 to 18‐crown‐6.