Hydrogen bonding patterns and C-H...π interactions in the structure of the antiparkinsonian drug (R)-rasagiline mesylate determined using laboratory and synchrotron X-ray powder diffraction data.

The structure of (R)-rasagiline mesylate [(R)-RasH·Mes], an active pharmaceutical ingredient used to treat Parkinson's disease, is presented. The structure was determined from laboratory and synchrotron powder diffraction data, refined using the Rietveld method, and validated and optimized using dispersion-corrected DFT calculations. The unit-cell parameters obtained in both experiments are in good agreement and the refinement with both datasets converged to good agreement factors.

Crystal structure from X-ray powder diffraction data, DFT-D calculation, Hirshfeld surface analysis, and energy frameworks of ()-trichlorme-thia-zide.

The structure of racemic ()-trichlorme-thia-zide [systematic name: ()-6-chloro-3-(di-chloro-meth-yl)-1,1-dioxo-3,4-di-hydro-2-1λ,2,4-benzo-thia-di-azine-7-sulfonamide], CHClNOS (-TCMZ), a diuretic drug used in the treatment of oedema and hypertension, was determined from laboratory X-ray powder diffraction data using [David (2006 ▸). , 910-915.], refined by the Rietveld method with [Coelho (2018 ▸).

Synthesis, crystal structure, Hirshfeld surface analysis and energy framework calculations of -3,7,9,9-tetra-methyl-10-(prop-2-yn-1-yl)-1,2,3,4,4a,9,9a,10-octa-hydro-acridine.

The title heterocyclic compound, CHN, has been prepared in good yield (72%) a BiCl-catalyzed cationic Povarov reaction between -propargyl-4-methyl-aniline and (±)-citronellal. The X-ray single-crystal study indicates that the structure consists of mol-ecules connected by C-H⋯π contacts to produce chains, which pack in a sandwich-herringbone fashion along the -axis direction. Hirshfeld surface analysis indicates that H⋯H inter-actions dominate by contributing 79.

4,6-Dimethyl-2-(3-pyridyl)quinolin-5-amine.

The title compound, C(16)H(15)N(3), shows a hindrance effect between adjacent amino and methyl groups that leads to a structural distortion, which is reflected in the non-planarity of the quinoline entity and in the bond angles and distances. The crystal packing consists of chains along the b axis sustained by an intermolecular hydrogen bond between the amino group and the N atom of the pyridyl ring.