Vibegron Impurity 58

tert-Butyl (1-oxo-1-phenylhex-5-yn-2-yl)carbamate; Carbamic acid, N-(1-benzoyl-4-pentyn-1-yl)-, 
1,1-dimethylethyl ester; 1,1-Dimethylethyl N-(1-benzoyl-4-pentyn-1-yl)carbamate;