Pseudopolymorphism in hydroxybenzophenones: the dihydrate of 2,2',4,4'-tetrahydroxybenzophenone.

A dihydrate pseudopolymorph of bis(2,4-dihydroxyphenyl)methanone, C(13)H(10)O(5)·2H(2)O, (I), was obtained during polymorphism screening of hydroxybenzophenone derivatives. This structure, in which the molecule sits on a twofold axis, was compared with the known anhydrous form of (I) [Schlemper (1982). Acta Cryst. B38, 554-559]. The role of water in the crystal assembly was established on the basis of the known monohydrate pseudopolymorph of 3,4-dihydroxybenzophenone [Landre, Souza, Corrêa, Martins & Doriguetto (2010). Acta Cryst. C66, o463-o465].

1-(2-[4-[6-Hydroxy-2-(4-hydroxyphenyl)benzo[b]thiol-3-ylcarbonyl]phenoxy]ethyl)piperidinium chloride.

The title compound, raloxifene hydrochloride, C(28)H(28)NO(4)S(+).-Cl(-), belongs to the benzothiophene class of antiosteoporotic drugs. In the molecular cation, the 2-phenol ring sustains a dihedral angle of 45.3 (1) degrees relative to the benzo[b]thiophene system. The benzo[b]thiophene and phenyl ring planes are twisted with respect to the carbonyl plane, with the smallest twist component occurring between the phenyl and carbonyl planes. The N atom bears the positive charge in the molecular cation and the piperidine ring adopts an almost perfect chair conformation. The Cl(-) anion is involved in the formation of N-H...Cl and O-H...Cl intermolecular hydrogen bonds, which lead to the formation of a layer of molecular cations.

6-Deoxyjacareubin.

The natural compound 5,10-dihydroxy-2,2-dimethylpyrano[3,2-b]xanthen-6(2H)-one (6-deoxyjacareubin), C(18)H(14)O(5), was isolated from leaves of Vismia latifolia (Guttiferae family). The compound has four six-membered rings. The molecule has two planar benzenoid and one planar pyranoid ring, plus a pyranoid ring in a distorted chair conformation. The crystal is stabilized by one intra- and one intermolecular hydrogen bond.