2-(5-Cyclohexyl-3-methylsulfanyl-1-benzofuran-2-yl)acetic acid

In the title compound, C17H20O3S, the cyclohexyl ring adopts a chair conformation. In the crystal, the carboxyl groups are involved in intermolecular O—H⋯O hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further stabilized by weak intermolecular C—H⋯O hydrogen bonds. In addition, the crystal structure also exhibits aromatic π–π interactions between the furan rings of adjacent molecules [centroid–centroid distance = 3.505 (2) Å, interplanar distance = 3.385 (2) Å and slippage = 0.909 (2) Å], and intermolecular C—H⋯π interactions.

In the title compound, C 17 H 20 O 3 S, the cyclohexyl ring adopts a chair conformation. In the crystal, the carboxyl groups are involved in intermolecular O-HÁ Á ÁO hydrogen bonds, which link the molecules into centrosymmetric dimers. These dimers are further stabilized by weak intermolecular C-HÁ Á ÁO hydrogen bonds. In addition, the crystal structure also exhibits aromaticinteractions between the furan rings of adjacent molecules [centroid-centroid distance = 3.505 (2) Å , interplanar distance = 3.385 (2) Å and slippage = 0.909 (2) Å ], and intermolecular C-HÁ Á Á interactions.
herein the crystal structure of the title compound.
In the title molecule, Fig. 1, the benzofuran unit is essentially planar, with a mean deviation of 0.006 (1)Å from the least-squares plane defined by the nine constituent atoms. The cyclohexyl ring has the chair-conformation. In the crystal structure, the carboxyl groups are involved in intermolecular O-H···O hydrogen bonds ( Fig. 2 Fig. 3, also exhibits aromatic π-π interactions between the furan rings of the adjacent molecules, with a Cg1···Cg1 iv distance of 3.505 (2)Å and an interplanar distance of 3.385 (2)Å resulting in a slippage of 0.909 (2)Å (Cg1 is the centroid of C1/C2/C7/O1/C8 furan ring). Additionally, the crystal packing ( Fig. 3) shows intermolecular C-H···π interactions; the first one between a cyclohexyl H atom and the furan ring (Table 1; C13-H13A···Cg1 iii ), the second one between a cyclohexyl H atom and the benzene ring (Table 1; C14-H14B···Cg2 iii ), and the third one between an H atom of the benzylic methylene group and the benzene ring (Table 1; C15-H15A···Cg2 iv , Cg2 is the centroid of the C2-C7 benzene ring). Symmetry codes as in the Table 1
Water was added, and the solution was extracted with dichloromethane. The aqueous layer was acidified to pH = 1 with concentrated hydrochloric acid and then extracted with chloroform, dried over magnesium sulfate, filtered and concentrated at reduced pressure. The residue was purified by column chromatography (ethyl acetate) to afford the title compound as a colourless solid [yield 83%, m.p. 423-424 K; R f = 0.45 (ethyl acetate)]. Single crystals suitable for X-ray diffraction were prepared by evaporation of a solution of the title compound in diisopropyl ether at room temperature.
supplementary materials sup-2 Refinement All H atoms were positioned geometrically and refined using a riding model, with O-H = 0.84Å, and C-H = 0.95Å for aryl, 1.00Å for methine, 0.99Å for methylene and 0.98Å for methyl H atoms, respectively. U iso (H) = 1.5U eq (O), and 1.2U eq (C) for aryl, methine, and methylene and 1.5U eq (C) for methyl H atoms. Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as a small spheres of arbitrary radius.  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.