title: Synthesis and structural elucidation of a novel polymorph of alcaftadine.
abstract: In this study, we have synthesized and elucidated the structure of the H1 histamine antagonist, 2-(1-methylpiperidin-4-ylidene)-4,7-diazatricyclo[8.4.0.0((3,7))]tetradeca-1(14),3,5,10,12-pentaene-6-carbaldehyde in the solution and solid-state. We have also studied the thermal dilapidation of the compound. Solution structure analysis was achieved by employing NMR spectroscopy including 2D experiments NOESY, HSQC and HMBC, while solid state investigations were undertaken using SXRD, PXRD, TGA, DSC, and IR spectroscopy. For the first time the single crystal structure of alcaftadine has now been solved. Crystallographic data are as follows: monoclinic, Cc, a=11.5694(6)Å, b=14.5864(6)Å, c=10.2688(4)Å, α=90°, β=111.793(3)°, γ=90°, V=1609.07(13)Å(3), Z=4. The Hirshfeld surface analyses also have been performed using the crystal structure.
authors.affiliation: School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa.
authors.forename: Pramod B
authors.initials: PB
authors.lastname: Pansuriya
authors.affiliation: School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa.
authors.forename: Glenn E M
authors.initials: GE
authors.lastname: Maguire
authors.affiliation: School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa. Electronic address: friedric@ukzn.ac.za.
authors.forename: Holger B
authors.initials: HB
authors.lastname: Friedrich
mesh_terms: D001552:Benzazepines / Q000138:chemical synthesis / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D018360:Crystallography, X-Ray; D006634:Histamine H1 Antagonists / Q000138:chemical synthesis / Q000737:chemistry*; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D013818:Thermogravimetry
chemical_list: D001552:Benzazepines; D006634:Histamine H1 Antagonists; D007093:Imidazoles; C557708:alcaftadine
keywords: 2D NMR; Alcaftadine; Polymorph; Single crystal structure; Thermal study