Multicomponent crystals of erlotinib

Erlotinib [systematic name: N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine], a small-molecule epidermal growth factor receptor inhibitor, useful for the treatment of non-small-cell lung cancer, has been crystallized as erlotinib monohydrate, C(22)H(23)N(3)O(4).H(2)O, (I), the erlotinib hemioxalate salt [systematic name: 4-amino-N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-1-ium hemioxalate], C(22)H(24)N(3)O(4)(+).0.5C(2)O(4)(2-), (II), and the cocrystal erlotinib fumaric acid hemisolvate dihydrate, C(22)H(23)N(3)O(4).0.5C(4)H(4)O(4).2H(2)O, (III). In (II) and (III), the oxalate anion and the fumaric acid molecule are located across inversion centres. The water molecules in (I) and (III) play an active role in hydrogen-bonding interactions which lead to the formation of tetrameric and hexameric hydrogen-bonded networks, while in (II) the cations and anions form a tetrameric hydrogen-bonded network in the crystal packing. The title multicomponent crystals of erlotinib have been elucidated to study the assembly of molecules through intermolecular interactions, such as hydrogen bonds and aromatic pi-pi stacking.

Crystal and molecular structures of 4-aryl-1,4-dihydropyrimidines: Novel calcium channel antagonists

The solid-state structures of three calcium channel antagonists viz. 1,4-dihydro-6-methyl-5-N-methyl-carbamoyl-4-(3′,4′-dichlorophenyl)-2(3 H)-pyrimidinethione, C13H13N3OSCl2 (1); 1,4-dihydro-6-methyl-5-N-methyl-carbamoyl-4-(4′-methoxyphenyl)-2(3 H)-pyrimidinethione, C14H17N3O2S (2) and 1,4-dihydro-6-methyl-5-N-methyl-carbamoyl-4-(2′,4′-dichlorophenyl)-2(3 H)-pyrimidineone monohydrate, C13H13N3O2Cl2·H2O (3), are reported here. The structures show that these compounds can adopt the important structural features of 1,4-dihydropyridine calcium channel blockers. In (2), the compound crystallized with three molecules in the asymmetric unit. The dihydropyrimidine ring adopts a half-chair in (1) and boat conformation in (2) and (3). The 4-aryl substituents occupies a pseudo-axial position approximately orthogonal to the plane of the dihydropyrimidine ring [95.1(2)° (1); 97.5(3)°, 79.8(2)° & 88.2(2)° (2) and 78.8(3)° (3)]. The C3 substituent, carbamoyl group, is in an extended conformation and oriented anticlinical in (1) and (3), but in (2) two molecules are anticlinal and the other one is synperiplanar, respectively. Intra- and inter- molecular interactions may be influencing the orientation of the C3 carbamoyl group. The 2-chlorophenyl substituent in (3) is in the axial synperiplanar orientation.

A neo-clerodane diterpene from Teucrium tomentosum. Corrigendum

Corrigendum to Acta Cryst. (2004), E60, o117–o119.

The chemical name of the title compound in the paper by Devi, Malathi, Rajan, Aravind, Krishnakumari & Ravikumar [Acta Cryst. (2004), E60, o117–o119] is corrected and the structural diagram is updated.

Methyl 2-(2,2,4-trimethyl-6-tosylperhydro-1,3-dioxino[5,4-c]pyridin-5-yl)acetate

The title compound, C₂₀H₂₉NO₆S, crystallizes with two mol­ecules in the asymmetric unit, with similar conformations. The dioxane and pyridine rings adopt twist conformations in both mol­ecules. The packing is stabilized by inter­molecular C—H⋯O hydrogen bonds.

Darifenacin hydro-bromide

In the title compound {systematic name: (S)-3-[(aminocar­bonyl)diphenylmethyl]-1-[2-(2,3-di­hy­dro­benzofuran-5-yl)ethyl]pyrrolidinium bromide}, C₂₈H₃₁N₂O₂⁺·Br⁻, the pyrrolidine rings adopts an envelope conformation. The two phenyl rings make a dihedral angle of 72.5 (1)°. The four coplanar atoms of the pyrrolidine ring makes dihedral angles of 33.1 (2) and 82.8 (2)° with the two phenyl rings. The mol­ecular conformation is influenced by a C—H⋯O inter­action. In the crystal packing, there are two N—H⋯Br hydrogen bonds running in opposite directions. They appear to form C(10) and C(9) chain motifs in the unit cell. In addition, the mol­ecular packing is further stabilized by C—H⋯Br and C—H⋯O hydrogen bonds. The C atom bonded to the benzofuran ring system is disordered in a 0.66:0.34 ratio.

Bis(S-benzyl-isothio-uronium) tetra-chloridozincate(II)

The asymmetric unit of the title compound, (C(8)H(11)N(2)S)(2)[ZnCl(4)], contains two S-benzyl-isothio-uronium cations which differ in the C-C-S-C torsion angle [165.3 (2) and 81.9 (2)°] and a tetrahedral tetra-chloridozincate anion. The crystal structure is stabilized by N-H⋯Cl, C-H⋯Cl and C-H⋯S inter-actions.

1-Vinyl-1H-indole-3-carbaldehyde

In the title compound, C₁₁H₉NO, the C and O atoms of the attached carbaldehyde group deviate by just 0.052 (2) and 0.076 (1) Å, respectively, from the mean plane of the indole ring system. In addition to van der Waals forces, the mol­ecular packing is stabilized by C—H⋯O hydrogen bonds, which form a C(7) chain motif, and π–π inter­actions (centroid–centroid distance 3.637 Å) between the pyrrole and benzene rings of the indole ring system.

Erlotinib hydro-chloride: an anti-cancer agent

In the cation of the title compound, C₂₂H₂₄N₃O₄⁺·Cl⁻, an active ingredient of the anti­cancer drug also known as Tarceva, the quinazoline ring system is planar within 0.044 (3) Å. The dihedral angle formed by the mean planes of the two six-membered quinazoline rings is 3.2 (1)°. Both N-bound H atoms participate in N—H⋯Cl bonds, which link the ions into infinite chains running along the b axis. C—H⋯O inter­actions involving neighboring cations provide additional stabilization of these aggregates.