Montelukast Dicyclohexylamine Standard

1-[1-[[[(1R)-1-[3-[(1E)-2-(7-Chloro-2-quinolinyl)ethenyl]phenyl]-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropaneacetic N-Cyclohexylcyclohexanamine; Montelukast DCHA (USP);