Description:
<jats:title>Abstract</jats:title><jats:p>Cystic fibrosis is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) protein. In the search of novel series of CFTR modulators, a library of mono and diacyl thioureas were prepared by sequential synthesis. When tested alone, the obtained compounds <jats:bold>5</jats:bold> and <jats:bold>6</jats:bold> poorly affected F508del‐CFTR conductance but, in combination with Lumacaftor, selected derivatives showed the ability to increase the activity of the approved modulator. Analogue <jats:bold>6 i</jats:bold> displayed the most marked enhancing effect and acylthioureas <jats:bold>6 d</jats:bold> and <jats:bold>6 f</jats:bold> were also able to improve efficacy of Lumacaftor. All compounds proved to be non‐cytotoxic against different cancer cell lines. Good pharmacokinetic properties were predicted for derivatives <jats:bold>5</jats:bold> and <jats:bold>6</jats:bold>, thus supporting the value of these compounds for the development of novel modulators potentially useful for cystic fibrosis.</jats:p>