Tosylate salts of the anticancer drug lapatinib

Two tosylate salts of an anticancer drug lapatinib, viz. a monotosylate [systematic name: ({5‐[4‐({3‐chloro‐4‐[(3‐fluorophenyl)methoxy]phenyl}amino)quinazolin‐6‐yl]furan‐2‐yl}methyl)[2‐(methylsulfonyl)ethyl]azanium 4‐methylbenzenesulfonate], C29H27ClFN4O4S+·C7H7O3S−, (I), and a ditosylate [systematic name: 4‐({3‐chloro‐4‐[(3‐fluorophenyl)methoxy]phenyl}amino)‐6‐]5‐({[2‐(methylsulfonyl)ethyl]azaniumyl}methyl)furan‐2‐yl[quinazolin‐1‐ium bis(4‐methylbenzenesulfonate)], C29H28ClFN4O4S2+·2C7H7O3S−, (II), were obtained during crystallization attempts for polymorphism. In both structures, the lapatinib cation is in a distorted U‐like conformation and the tosylate anion is clamped between the aniline N atom and methylamine N atom through N—H...O hydrogen bonds, forming an R22(15) ring motif. The 4‐anilinoquinazoline ring system is essentially planar in (I), while it is twisted in (II), controlled by an intramolecular C—H...N interaction. In (I), alternating cations and anions are linked by N—H...O hydrogen bonds into C22(6) chains. These chains are linked by cations in a helical manner. The presence of the additional tosylate anion in (II) results in the formation of one‐dimensional tapes of fused hydrogen‐bonded rings through N—H...O and C—H...O interactions. These studies augment our understanding of the role of nonbonded interactions in the solid state, which is useful for correlation to the physicochemical properties of drug products.