Ethyl 2,4-dihydroxy-6-methylbenzoate

Definition

ChEBI: 2,4-dihydroxy-6-methylbenzoic acid ethyl ester is a 4-hydroxybenzoate ester.

General Description

Ethyl 2,4-dihydroxy-6-methylbenzoate is also referred as ethyl orsellinate. It was isolated from chloroform extract of Peltigera aphthosa. It is one of the product formed during alcoholyses of lecanoric acid.

Synthesis

The stem bark of Illicium difengpi (5.0?kg) was powdered and extracted three times with aqueous ethanol (ethanol/water 8:2) under reflux. The solvent was then evaporated under reduced pressure to obtain a dry residue (150?g). The residue was suspended in water (2?L) and extracted successively with petroleum ether (3 × 2?L), EtOAc (3 × 2?L) and BuOH (3 × 2?L), affording 5?g, 70?g, and 40?g, respectively, of each dried fraction. The EtOAc fraction was subjected to silica gel column chromatography using gradient elution (CH2Cl2/CH3OH, 200:1 to 2:1, v/v) to give four main fractions, of which was purified by successive silica gel column chromatography (CH2Cl2/CH3OH, 100:1→20:1); 2,4-dihy-droxy-6-methyl-benzoic acid ethyl ester (Ethyl 2,4-dihydroxy-6-methylbenzoate) was obtained from the fraction eluted by CH2Cl2/CH3OH (40:1)[1].

Structure and conformation

The mol-ecular structure of Ethyl 2,4-dihydroxy-6-methylbenzoate contains a methyl group, two hydroxyl groups, and a carboeth-oxy group, which are attached to C2, C4, C6 and C7 of the central benzene ring, respectively. An intra-molecular O3—H3···O1 hydrogen bond stabilizes the mol-ecular conformation. In the crystal, O4—H4···O3ⁱ and C3—H3A···O4ⁱⁱ hydrogen bonds link the mol-ecules into double strands parallel to the direction. In the solid state, the compound also forms offset slanted stacks of alternating inversion-related mol-ecules along the a-axis direction[1].

References

[1] Xiong, Huiping , et al. "Crystal structure of the ethyl 2,4-dihydroxy-6-methylbenzoate from Illicium difengpi K.I.B et K.I.M. " IUCrData 12(2018).