Process for making modulators of cystic fibrosis transmembrane conductance regulator

A process for the preparation of a compound of Formula 1,

• or a pharmaceutically acceptable salt thereof, comprising:
• (a) coupling a carboxylic acid of Formula 2,
• or a pharmaceutically acceptable salt thereof, with an aniline of Formula 3,
• or a pharmaceutically acceptable salt thereof, in the presence of a coupling agent under conditions sufficient to produce a compound of Formula 4,
• or a pharmaceutically acceptable salt thereof;
• and
• (b) cleaving the methoxy formyl protecting group from the phenolic oxygen atom of Formula 4 under conditions sufficient to yield a compound of Formula 1, or a pharmaceutically acceptable salt thereof.