Process for making modulators of cystic fibrosis transmembrane conductance regulator

1. 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.

2. A compound of Formula 3, or a pharmaceutically acceptable salt thereof.

3. A compound of Formula 4, or a pharmaceutically acceptable salt thereof.