Binary co-crystals of the active pharmaceutical ingredient 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene and camphoric acid

Abstract

Co-crystals comprising the active pharmaceutical ingredient 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene, C12H10N4, and the chiral co-formers (+)-, (-)- and (rac)-camphoric acid (cam), C10H16O4, have been synthesized. Two different stoichiometries of the API and co-former are obtained, namely 1:1 and 3:2. Crystallization experiments suggest that the 3:2 co-crystal is kinetically favoured over the 1:1 co-crystal. Single-crystal X-ray diffraction analysis of the co-crystals reveals N-H...O hydrogen bonding as the primary driving force for crystallization of the supramolecular structures. The 1:1 co-crystal contains undulating hydrogen-bonded ribbons, in which the chiral cam molecules impart a helical twist. The 3:2 co-crystal contains discrete Z-shaped motifs comprising three molecules of the API and two molecules of cam. The 3:2 co-crystals with (+)-cam, (-)-cam (space group P21) and (rac)-cam (space group P21/n) are isostructural. The enantiomeric co-crystals contain pseudo-symmetry consistent with space group P21/n, and the co-crystal with (rac)-cam represents a solid solution between the co-crystals containing (+)-cam and (-)-cam.

Facile Green Synthesis of New Copper-Based Metal–Organic Frameworks: Experimental and Theoretical Study of the CO2 Fixation Reaction

“…Herein, we report the preparation of a novel class of triply interpenetrated Cu­(II)-based dual ligand MOFs, [Cu­(BDC)­(BPDB) 0.5 ] n (PNU-25) and [Cu­(NH 2 -BDC)­(BPDB) 0.5 ] n (PNU-25-NH 2 ), composed of an N-donor Schiff base ligand, 1,4-bis­(4-pyridyl)-2,3-diaza-1,3-butadiene (BPDB), along with 1,4-benzene­dicarboxylic acid (BDC) (for PNU-25) and 2-amino­terephthalic acid (NH 2 -BDC) (for PNU-25-NH 2 ), using a H 2 O–MeOH solvent mixture, and their structural analysis using single-crystal X-ray diffraction (SXRD).…”

Cocrystal of phloretin with isoniazid: preparation, characterization, and evaluation

“…30 Many relevant isoniazid-based cocrystals have been reported. [39][40][41][42][43][44] The structure of Phl-Inz crystallized in the triclinic space group P 1 (Table 1), with two molecules of Phl and Inz in the asymmetric unit. A unit cell contains two asymmetric units.…”

Charge density and optical properties of multicomponent crystals containing active pharmaceutical ingredients or their analogues

“…Urea and mnitrobenzoic acid co-crystals (Rai et al, 2002) have a SHG intensity comparable with that of urea, whereas the hardness of the material is much improved in the binary crystal. Two out of three pharmaceutical co-crystals of 1,4-bis(4-pyridyl)-2,3diaza-1,3-butadiene and camphoric acid are non-centrosymmetric (Bisht et al, 2014) and are built of optically active, flexible organic nitrogen-donor molecules. Co-crystals and salts of amino acids are known NLO materials: l-ornithine monohydrochloride (Senthil et al, 2009) l-phenylalaninebenzoic acid co-crystals, LPBA (Geetha et al, 2011); glycine oxalic acid co-crystals, GOA (Pandey, 2014); glycine thiourea co-crystals, GT (Ruby & Raj, 2013); l-histidinium hydrogen oxalate .…”