3,5-Dihydroxybenzoic acid methyl ester

slightly yellow to beige fine crystalline powder

The approach described by Brouwer et al. (ibid.) for the convergent synthesis of amino acid based dendrimers was adapted in order to obtain dendrimers with surface propargyl groups to enable a 1, 3-dipolar cycloaddition (click) reaction with amino acid /peptide derived azides. First generation dendrimer 1 was synthesized from 3, 5-dihydroxybenzoic acid in an overall yield of 81percent as shown in Scheme 1. In detail, 3, 5-dihydroxymethylbenzoate (21.4 g, 130 mmol) was dissolved in dry DMF (250 mL) and anhydrous KGeneral procedure: Thionyl chloride (1.16 g, 1.5 equiv) was added drop-wise to a solution of acid (1.0 g, 1.0 equiv) in the corresponding alcohol (15 ml) at 0&d eg;C. The solution was refluxed under a nitrogen atmosphere until all starting material was consumed (TLC monitoring). Then the solvent was removed under vacuo and the residue was purified by silica gel column chromatography eluting with ethyl acetate/n-hexane to afford the corresponding carboxylic esters.#10;To a solution of 8a (10.00 g, 64.9 mmol) in methanol (50 mL) was added concentrated sulfuric acid(750 μL in 10 mL methanol), and the solution was allowed to reflux for 8 h. After cooled to ambient temperature, methanol was evaporated under reduced pressure and the residue was dissolved in ethylacetate (50 mL), which was then washed with saturated NaHCO3 solution and water. The organic layer was dried over anhydrous Na2SO4 and ethyl acetate was removed in vacuo to afford of methyl3, 5-dihydroxylbenzoate 8a′ (10.74 g, 98percent) as a white powder.A solution of 3, 5-dihydroxybenzoic acid (20.0 g, 129.9 mmol) in dry methanol (100 mL) and HMethyl 3, 5-dihydroxybenzoate (8)To a solution of 3, 5-dihydroxybenzoic acid (5.0 g, 32 mmol) in methanol (170 ml) was added a catalytic amount of sulphuric acid (0.3 ml). After stirring at reflux overnight, the mixture was cooled and neutralized with 4M NaOH (aq. solution). After concentration, the residue was dissolved in ethyl acetate and washed with water and brine. The organic layer was dried (Na1. Preparation of 3, 5-dihydroxybenzoic acid methyl ester (1); To a solution of 3, 5-dihydroxybenzoic acid (10 g, 64.9 mmol) in anhydrous methanol (150 mL) acetyl chloride (2 mL, 28.1 mmol) was added dropwise. The mixture was heated at reflux under NTo the solution of anhydrous methanol (150 mL) was added slowly acetyl chloride (2 mL, 28.1 mmol) followed by the solution of 3, 5-dihydroxybenzoic acid (10 g, 64.9 mmol). The mixture was refluxed under nitrogen for 17 hours. The solvent was evaporated and the residue was dissolved in ethyl acetate (100 mL), and washed with saturated sodium hydrogen carbonate (3 × 100 mL). The organic layer was washed with distilled water (2 × 100 mL), dried over sodium sulfate, filtered and evaporated under reduced pressure to afford 2 as an off white solid (9.80 g, yield 90percent), mp 167-168°C (lit.[32] mp 168-169°C). Then, under an argon atmosphere, in a 300 mL flask, 3, 5-dihydroxybenzoic acid (8.0 g, 51.9 mmol, 1 eq.) Was dissolved in dry methanol (40 mL).Subsequently, thionyl chloride (7.4 g, 4.5 mL, 62 mmol, 1.2 eq.) Was added dropwise, and the flask was heated on an oil bath and reacted at 60 ° C. with stirring for 2 hours.The mixture was then cooled to room temperature and the volatiles evaporated under reduced pressure. Then, the solid precipitate was suspended in toluene, The volatiles were evaporated to give compound (A-4) as a beige solid (yield 7.79 g, 46.3 mmol, yield 89percent).Conc. HA)

The methyl ester of 3,5-Dihydroxybenzoic Acid (D451700) with potential antifeedant activity for pine weevil, Hylobius abietis.

Molecular Weight:168.15
XLogP3:1.5
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:2
Exact Mass:168.04225873
Monoisotopic Mass:168.04225873
Topological Polar Surface Area:66.8
Heavy Atom Count:12
Complexity:158
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes