Isopropyl 3,4,5-trihydroxybenzoate

In the title compound, C10H12O5, the dihedral angle between the benzene ring is almost coplanar with the attached C(O)—O—C group [dihedral angle = 0.32 (15)°]. In the crystal, two intermolecular O—H⋯O hydrogen bonds make R 4 4(26) ring mofits.

In the title compound, C 10 H 12 O 5 , the dihedral angle between the benzene ring is almost coplanar with the attached C(O)-O-C group [dihedral angle = 0.32 (15) ]. In the crystal, two intermolecular O-HÁ Á ÁO hydrogen bonds make R 4 4 (26) ring mofits.

Comment
Pharmacological studies indicate the title compound, (I), has antioxidant, anti-apoptotic and anti-platelet activities suggesting it could be a new drug with therapeutic effects on cardiovascular or cerebrovascular diseases. (Calheiros et al., 2008;Morais et al., 2010).
Experimental 0.01M p-toluenesulfonic acid in 2-propanol was added to a solution of 0.1M gallic acid in 500 ml of 2-propanol at room temperature. After being stirred and refluxed for 16 h, the solvent was removed under reduced pressure and the residue was extracted three times with ethyl acetate and filtered. The filtrate was washed successively with dilute saturated aqueous NaHCO 3 solution, saturated aqueous NaCl solution, dried over MgSO 4 and was evaporated to dryness. The crude product was purified by chromatography (SiO 2 ; elution with petroleum ether and ethyl acetate, 5:1 v/v). Yield 36%. (Christiansen, 1926;Li et al., 2001).
X-ray quality crystals were obtained from a solution of the title compound in acetone and toluene at room temperature.

Refinement
H atoms bonded to O atoms were located in a difference map and their positions adjusted to give O-H = 0.82 Å. Other H atoms were positioned geometrically with C-H = 0.93-0.96 Å. All were included as riding contributions (including free rotation about the ethanol C-C bond) with U iso (H) = 1.2U eq (O or C) or 1.5U eq (C).

Figure 2
The packing of (I) viewed down the a axis with O-H···O hydrogen bonds shown as dashed lines.

Isopropyl 3,4,5-trihydroxybenzoate
Crystal data 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 > σ(F 2 ) is used only for calculating R-factors(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.