Premium
Pyridine and 3‐methylpyridine solvates of the triple sulfa drug constitutent sulfamethazine
Author(s) -
Patel Urmila H.,
Purohit Ketankumar P.
Publication year - 2017
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229616015898
Subject(s) - chemistry , orthorhombic crystal system , pyridine , hydrogen bond , intramolecular force , crystal structure , molecule , crystallography , solvent , crystal engineering , intermolecular force , sulfonyl , stereochemistry , medicinal chemistry , organic chemistry , alkyl
Sulfonamides display a wide variety of pharmacological activities. Sulfamethazine [abbreviated as SMZ; systematic name 4‐amino‐ N ‐(4,6‐dimethylpyrimidin‐2‐yl)benzenesulfonamide], one of the constitutents of the triple sulfa drugs, has wide clinical use. Pharmaceutical solvates are crystalline solids of active pharmaceutical ingredients (APIs) incorporating one or more solvent molecules in the crystal lattice, and these have received special attention, as the solvent molecule can impart characteristic physicochemical properties to APIs and solvates, therefore playing a significant role in drug development. The ability of SMZ to form solvates has been investigated. Both pyridine and 3‐methylpyridine form solvates with SMZ in 1:1 molar ratios. The pyridine monosolvate, C 12 H 14 N 4 O 2 S·C 5 H 5 N, crystallizes in the orthorhombic space group Pna 2 1 , with Z = 8 and two molecules per assymetric unit, whereas the 3‐methylpyridine monosolvate, C 12 H 14 N 4 O 2 S·C 6 H 7 N, crystallizes in the orthorhombic space group P 2 1 2 1 2 1 , with Z = 4. Crystal structure analysis reveals intramolecular N—H…N hydrogen bonds between the molecules of SMZ and the pyridine solvent molecules. The solvent molecules in both structures play an active part in strong intermolecular interactions, thereby contributing significantly to the stability of both structures. Three‐dimensional hydrogen‐bonding networks exist in both structures involving at least one sulfonyl O atom and the amine N atom. In the pyridine solvate, there is a short π–π interaction [centroid–centroid distance = 3.926 (3) Å] involving the centroids of the pyridine rings of two solvent molecules and a weak intermolecular C—H…π interaction also contributes to the stability of the crystal packing.