title: Identification, synthesis, isolation and spectral characterization of potential impurities of montelukast sodium.
abstract: During the process development of montelukast sodium, three polar impurities and one non-polar impurity with respect to montelukast sodium were detected by simple reverse phase high-performance liquid chromatography (HPLC). Initially, all the four impurities were identified by the liquid chromatography-mass spectrometry (LC-MS) data and out of four impurities, three have been prepared by the synthetic method and remaining one is isolated by preparative HPLC. Based on the spectral data (IR, (1)H NMR, (13)C NMR and MS), the structure of these impurities 1-4 were characterised as 1-[[[(1R)-1-[3-[(1E)-2-(7-chloro-2-quinolinyl)ethenyl]phenyl-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropane acetamide (impurity-1), {1-[1-{3-[2-(7-chloro-quinolin-2-yl)-vinyl]-phenyl}-3-(2-isopropenyl-phenyl)-propylsulfanylmethyl]-cyclopropyl}-acetic acid (impurity-2), 1-[[[(1R)-1-[3-[(1E)-2-(7-chloro-2-quinolinyl)ethyl]phenyl-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropaneacetic acid (impurity-3) and 1-[[[(1R)-1-[3-[(1E)-2-(2-quinolinyl)ethenyl]phenyl-3-[2-(1-hydroxy-1-methylethyl)phenyl]propyl]thio]methyl]cyclopropaneacetic acid (impurity-4).
authors.affiliation: Dr. Reddy's Laboratories Ltd., IPDO-IPM Communication No. 00056, Hyderabad, India.
authors.forename: M
authors.initials: M
authors.lastname: Saravanan
authors.forename: K
authors.initials: K
authors.lastname: Siva Kumari
authors.forename: P
authors.initials: P
authors.lastname: Pratap Reddy
authors.forename: M N
authors.initials: MN
authors.lastname: Naidu
authors.forename: J
authors.initials: J
authors.lastname: Moses Babu
authors.forename: Alok Kumar
authors.initials: AK
authors.lastname: Srivastava
authors.forename: T
authors.initials: T
authors.lastname: Lakshmi Kumar
authors.forename: B V V N
authors.initials: BV
authors.lastname: Chandra Sekhar
authors.forename: Bollikonda
authors.initials: B
authors.lastname: Satyanarayana