SHEPERD JON

Substituted pyrazino[1′,2′:1,2]pyrrolo[3,4-d]pyrimidines, pyrimido[4′,5′:3,4]pyrrolo[2,1-c][1,4]oxazines and pyrimido[4′,5′:3,4]pyrrolo[1,2-d][1,4]oxazepines for inhibiting the CFTR channel