Montelukast Ketocarbinol Impurity

Chemical Name: 1-[[[(1R)-1-[3-[(1E)-2-(7-Chloro-2-quinolinyl) ethenyl] phenyl]-3-[2-(1-oxo-2-hydroxyethyl) phenyl] propyl] thio] methyl] cyclopropaneacetic acid

Synonym: (4S,6S)-4-(ethylamino)-N-(((4S,6S)-4-(ethylamino)-6-methyl-7,7-dioxido-5,6-dihydro-4H-thieno[2,3-b]thiopyran-2-yl)sulfonyl)-6-methyl-5,6-dihydro-4H-thieno[2,3-b]thiopyran-2-sulfonamide 7,7-dioxide