3943-89-3

Basic information

• Product Name: Ethyl 3,4-dihydroxybenzoate
• Synonyms: 3,4-DIHYDROXYBENZOIC ACID ETHYL ESTER;ETHYL 3,4-DIHYDROXYBENZOATE;ETHYL PROTOCATECHUATE;RARECHEM AL BI 0069;PROTOCATECHUIC ACID ETHYL ESTER;3,4-dihydroxybenzate ethyl ester;3,4-DIHYDROXYBENZOIC ACID ETHYL ESTER 97%;3,4-DIHYDROXYBENZOIC ACID ETHYL ESTER 98+%
• CAS NO: 3943-89-3
• Molecular Formula: C₉H₁₀O₄
• Molecular Weight: 182.17
• EINECS: 223-529-0
• Product Categories: FINE Chemical & INTERMEDIATES;Aromatic Esters;Benzoic acid;Organic acids;API intermediates;Aromatics;Intermediates & Fine Chemicals;Pharmaceuticals;HIF Prolyl-Hydroxylase Inhibitors;Aerobic Glycolysis (the Warburg Effect);Building Blocks;C8 to C9;Cancer Metabolism;Cancer Research;Carbonyl Compounds;Chemical Synthesis;Esters;Inhibitors of Aerobic Glycolysis (the Warburg Effect);Organic Building Blocks
• Mol File: 3943-89-3.mol

Chemical Properties

• Melting Point: 132-134 °C(lit.)
• Boiling Point: 275.56°C (rough estimate)
• Flash Point: 147 °C
• Appearance: Pale yellow to beige/Crystalline Powder
• Density: 1.2481 (rough estimate)
• Vapor Pressure: 1.27E-05mmHg at 25°C
• Refractive Index: 1.4500 (estimate)
• Storage Temp.: Sealed in dry,Room Temperature
• PKA: 8.19±0.18(Predicted)
• Water Solubility: Insoluble in water. Soluble in ethanol.
• BRN: 2097435
• CAS DataBase Reference: Ethyl 3,4-dihydroxybenzoate(CAS DataBase Reference)
• NIST Chemistry Reference: Ethyl 3,4-dihydroxybenzoate(3943-89-3)
• EPA Substance Registry System: Ethyl 3,4-dihydroxybenzoate(3943-89-3)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-36-37/39
• WGK Germany: 3
• Hazardous Substances Data: 3943-89-3(Hazardous Substances Data)

Usage

Uses

Used in the Food Industry:
Ethyl 3,4-dihydroxybenzoate is used as an additive for its antioxidant properties, which help in preserving the quality and freshness of food products by preventing the oxidation of fats and oils.
Used in the Pharmaceutical Industry:
Ethyl 3,4-dihydroxybenzoate is used as a prolyl 4-hydroxylase inhibitor, which can be beneficial in protecting the myocardium and potentially treating heart-related conditions.
Used in the Cosmetic Industry:
Due to its antioxidant properties, ethyl 3,4-dihydroxybenzoate is also used in the cosmetic industry to extend the shelf life of products and protect them from oxidation, ensuring their stability and effectiveness.
Used in the Wine and Olive Oil Industry:
Ethyl 3,4-dihydroxybenzoate is found in Sicilian virgin olive oils and red wines, where it contributes to the antioxidant content of these products, enhancing their quality and health benefits.

InChI:InChI=1/C9H10O4/c1-2-13-9(12)6-3-4-7(10)8(11)5-6/h3-5,10-11H,2H2,1H3

Synthetic route

3,4-Dihydroxybenzoic acid (99-50-3) + ethanol (64-17-5) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With sulfuric acid Heating;	99%
With sulfuric acid at 50℃; for 3h;	98%
With sulfuric acid	98%

4-Benzyloxy-3-(4-methoxycarbonyl-benzyloxy)-benzoic acid ethyl ester → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With hydrogen; palladium on activated charcoal at 20℃; for 3h;	96%

ethyl vanillate (617-05-0) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With aluminium(III) iodide; N,N-dimethyl-formamide dimethyl acetal In acetonitrile at 80℃; for 18h; Reagent/catalyst;	94%
With aluminium(III) iodide; N,N-dimethyl-formamide dimethyl acetal In acetonitrile at 80℃; for 18h; Reagent/catalyst;	94%
With aluminium(III) iodide; ethyl acetate; diisopropyl-carbodiimide In acetonitrile at 20℃; for 2h; chemoselective reaction;	93%

4-Benzyloxy-3-(3-methoxycarbonyl-benzyloxy)-benzoic acid ethyl ester → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With hydrogen; palladium on activated charcoal at 20℃; for 3h;	93%

4-benzyloxy-3-(4-nitro-benzyloxy)-benzoic acid ethyl ester → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With hydrogen; palladium on activated charcoal at 20℃; for 3h;	92%

ethyl 3,4-dihydro-2H-benzo[b]1,4-dioxepine-7-carboxylate (20986-39-4) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With aluminum (III) chloride In benzene for 1h; Reflux;	90%

ethyl 4-oxocyclohexane-1-carboxylate (17159-79-4) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With iodine; oxygen; dimethyl sulfoxide at 80℃; for 12h;	84%

ethanol (64-17-5) + 4-(hydroxymethyl)benzene-1,2-diol (3897-89-0) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With dihydrogen peroxide for 3h; Irradiation;	83%

C17H28O4Si (1344113-41-2) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
Stage #1: C17H28O4Si With palladium(II) trimethylacetate; [bis(acetoxy)iodo]benzene In α,α,α-trifluorotoluene at 120℃; Inert atmosphere; Stage #2: With tetrabutyl ammonium fluoride In tetrahydrofuran at 20℃; Stage #3: With water In tetrahydrofuran	76%

ethyl 3-oxocyclohexanecarboxylate (33668-25-6) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
With iodine; oxygen; dimethyl sulfoxide at 80℃; for 12h; regioselective reaction;	53%

ethanol (64-17-5) + cyanidin 3-O-glucopyranoside chloride → Ethyl protocatechuate (3943-89-3) + glucopyranosyl 2-(3,4-dihydroxyphenyl)-4,6-dihydroxybenzofuran-3-carboxylate + C15H10O7 (1577235-12-1)

Conditions	Yield
With 2,2'-azobis-(2,4-dimethylvaleronitrile) at 60℃; for 4h;	A 33% B 28.2% C 9.6%

hydrogenchloride (7647-01-0) + 3,4-Dihydroxybenzoic acid (99-50-3) + ethanol (64-17-5) → Ethyl protocatechuate (3943-89-3)

3,4-Dihydroxybenzoic acid (99-50-3) + concentrated H2 SO4 → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
In ethanol	39 g (69%)
In ethanol	39 g (69%)
In ethanol	39 g (69%)

Ethyl 4-hydroxybenzoate (120-47-8) → Ethyl protocatechuate (3943-89-3)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: 1H-imidazole / tetrahydrofuran / 20 °C / Inert atmosphere 1.3: 20 °C 2.1: palladium(II) trimethylacetate; [bis(acetoxy)iodo]benzene / α,α,α-trifluorotoluene / 120 °C / Inert atmosphere 2.2: 20 °C View Scheme

Ethyl 4-hydroxybenzoate (120-47-8) → sorbic Acid (110-44-1) + formic acid (64-18-6) + glyceric acid (473-81-4) + Ethyl protocatechuate (3943-89-3) + benzene-1,2-diol (120-80-9) + hydroquinone (123-31-9) + phenol (108-95-2) + 4-hydroxy-benzoic acid (99-96-7)

Conditions	Yield
With dihydrogen peroxide; titanium(IV) oxide In water at 35℃; for 0.5h; pH=7.3; Concentration; Irradiation;

...Expand

ethanol (64-17-5) + cyanidin-3-O-glucoside → Ethyl protocatechuate (3943-89-3) + C15H10O7 (1577235-12-1) + C21H20O12

Conditions	Yield
With water; dihydrogen peroxide at 40℃; for 2h;

Ethyl protocatechuate (3943-89-3) + 2-Bromoethyl methyl ether (6482-24-2) → 3,4-bis(2-methoxyethoxy)benzoic acid ethyl ester (183322-16-9)

Conditions	Yield
With potassium carbonate; potassium iodide In acetone at 60℃; for 19h; Inert atmosphere;	100%
With potassium carbonate In acetone at 20 - 70℃; for 24h;	93%
With tetra-(n-butyl)ammonium iodide; potassium carbonate In acetone for 64h; Inert atmosphere; Reflux;	93%

Ethyl protocatechuate (3943-89-3) + 2,3-dimethyl-buta-1,3-diene (513-81-5) → ethyl 8-hydroxy-2,3-dimethyl-7-oxo-1,4,4a,7-tetrahydronaphthalene-4a-carboxylate

Conditions	Yield
With lithium perchlorate; acetic acid In nitromethane for 16h; electrolysis;	98%
With tetradecafluorohexane; lithium perfluorooctane sulfonate; acetic acid Diels-Alder reaction; Electrochemical reaction;	95%
In acetic acid electrochemical reaction: glass carbon anode (60x20 mm) coated with modified Nafion resin, Pt cathode (10x10 mm), aq. sodium dodecyl sulfate as supporting electrolyte, undivided cell 2.2 F mol-1, 0.8 V vs SCE; Yield given;

Ethyl protocatechuate (3943-89-3) + chloromethyl methyl ether (107-30-2) → ethyl 3,4-bis(methoxymethoxy)benzoate (959146-62-4)

Conditions	Yield
With N-ethyl-N,N-diisopropylamine; sodium iodide In N,N-dimethyl-formamide at 0 - 20℃; for 48h;	98%

Ethyl protocatechuate (3943-89-3) + isopropyl bromide (75-26-3) → ethyl 3,4-diisopropoxybenzoate (1369403-22-4)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20 - 60℃; for 19h; Inert atmosphere;	98%

Tetrafluorophthalonitrile (1835-65-0) + Ethyl protocatechuate (3943-89-3) → C26H16N2O8

Conditions	Yield
With potassium carbonate In acetonitrile at 80℃; for 3h;	98%

Ethyl protocatechuate (3943-89-3) + ethyl (E)-4-methyl-3,5-hexadienoate (76200-27-6) → 4-ethoxycarbonylmethyl-8-hydroxy-3-methyl-7-oxo-1,7-dihydro-4H-naphthalene-4a-carboxylic acid ethyl ester

Conditions	Yield
With lithium perchlorate; acetic acid In nitromethane for 16h; Ambient temperature; constant potential electrolysis on PTFE-fiber coated glassy carbon anode/Pt cathode (1200 mV vs. SCE);	97%

1-bromo dodecane (112-29-8) + Ethyl protocatechuate (3943-89-3) → ethyl 3,4-bis(dodecyloxy)benzoate (773135-90-3)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide	97%

Ethyl protocatechuate (3943-89-3) + p-methoxybenzyl chloride (824-94-2) → C25H26O6 (1401529-49-4)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 48h;	97%
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 48h;	97%

Ethyl protocatechuate (3943-89-3) → C9H8O4(2-)*Mg(2+)

Conditions	Yield
With magnesium hydroxide In water at 20℃; for 2h;	97%

ethyl (E)-3,5-hexadienoate (74054-58-3) + Ethyl protocatechuate (3943-89-3) → 4-ethoxycarbonylmethyl-8-hydroxy-7-oxo-1,7-dihydro-4H-naphthalene-4a-carboxylic acid ethyl ester

Conditions	Yield
With lithium perchlorate; acetic acid In nitromethane for 16h; Ambient temperature; constant potential electrolysis on PTFE-fiber coated glassy carbon anode/Pt cathode (1200 mV vs. SCE);	96%

Dichlorodiphenylmethane (2051-90-3) + Ethyl protocatechuate (3943-89-3) → 2,2-Diphenyl-1,3-benzodioxolane-5-carboxylic acid, ethyl ester (152361-07-4)

Conditions	Yield
at 170℃; for 0.166667h;	95%

2-chloroethyl methyl ether (627-42-9) + Ethyl protocatechuate (3943-89-3) → 3,4-bis(2-methoxyethoxy)benzoic acid ethyl ester (183322-16-9)

Conditions	Yield
With 4-(Methylamino)pyridine; potassium carbonate at 90 - 95℃; Temperature; Reagent/catalyst;	95%
With carbon dioxide; ammonia at 50℃; for 0.5h; Temperature; Reagent/catalyst;	94.6%
With potassium tert-butylate; potassium iodide In N,N-dimethyl-formamide at 100℃; for 12h;	87%
With tetra-(n-butyl)ammonium iodide; potassium carbonate In acetone for 120h; Heating;
With potassium carbonate In N,N-dimethyl-formamide at 90 - 100℃; for 9h;	95 %Chromat.

di-tert-butyl dicarbonate (24424-99-5) + Ethyl protocatechuate (3943-89-3) → 3,4-bis-tert-butoxycarbonyloxy-benzoic acid ethyl ester (918402-89-8)

Conditions	Yield
With dmap; triethylamine In dichloromethane at 0 - 20℃;	95%

thiophosgene (463-71-8) + Ethyl protocatechuate (3943-89-3) → ethyl 2-thioxobenzo[d][1,3]dioxole-5-carboxylate (33373-19-2)

Conditions	Yield
With sodium carbonate In water at 0 - 20℃;	95%
With dmap; carbon dioxide In dichloromethane; acetone at -78 - 20℃; for 19h;	51%

2-[2-(2-ethoxyethoxy)ethoxy]ethyl chloride (538371-55-0) + Ethyl protocatechuate (3943-89-3) → ethyl 3,4-bis-(2-(2-(2-ethoxyethoxy)ethoxy)ethoxy)benzoate (916817-35-1)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide	95%

1-[2-(ethoxy)ethoxy]-2-chloroethane (41771-35-1) + Ethyl protocatechuate (3943-89-3) → ethyl 3,4-bis-[2-(2-ethoxyehtoxy)ethoxy]benzoate (906550-98-9)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide	95%

2-methoxyethyl methanesulfonate (16427-44-4) + Ethyl protocatechuate (3943-89-3) → 3,4-bis(2-methoxyethoxy)benzoic acid ethyl ester (183322-16-9)

Conditions	Yield
With tetrabutylammomium bromide; potassium carbonate In toluene for 6h; Reflux;	95%
With potassium tert-butylate; tetrabutylammomium bromide In N,N-dimethyl-formamide at 30 - 40℃; for 10h;	90.5%

Ethyl protocatechuate (3943-89-3) + hexa(ethyleneglycol) ditosylate (42749-27-9) → C21H32O9

Conditions	Yield
With potassium hexafluorophosphate; potassium carbonate In acetonitrile for 12h; Reflux;	95%

Ethyl protocatechuate (3943-89-3) + dimethyl sulfate (77-78-1) → ethyl veratrate (3943-77-9)

Conditions	Yield
Stage #1: Ethyl protocatechuate With potassium carbonate In acetone at 20℃; for 0.5h; Stage #2: dimethyl sulfate at 50℃; for 5h;	94.5%

1-vinylcyclohexene (2622-21-1) + Ethyl protocatechuate (3943-89-3) → ethyl 2,4a,4b,5,6,7,8,10-octahydro-1-hydroxy-2-oxophenanthrene-4a carboxylate (1196885-37-6)

Conditions	Yield
With lead(II,IV) oxide; trifluoroacetic acid In tetrahydrofuran at 20℃; for 2.5h;	94%

Ethyl protocatechuate (3943-89-3) + 4’-[(10-bromodecyl)oxy]-4-carbonitrile-[1,1’-biphenyl] (140713-89-9) → 3,4-bis[6-(4'-cyanobiphenyl-4-yloxy)hexyloxy]benzoic acid ethyl ester (610785-23-4)

Conditions	Yield
With potassium carbonate; potassium iodide In butanone Heating;	93%

Ethyl protocatechuate (3943-89-3) + rhodamine B (509-34-2) → C28H30O3N2*C9H10O4

Conditions	Yield
In acetonitrile at 20℃; for 2.5h;	93%

1-methylbuta-1,3-diene (2004-70-8) + Ethyl protocatechuate (3943-89-3) → (4S,4aR)-8-Hydroxy-4-methyl-7-oxo-1,7-dihydro-4H-naphthalene-4a-carboxylic acid ethyl ester

Conditions	Yield
With lithium perchlorate; acetic acid In nitromethane for 16h; electrolysis;	92%

Ethyl protocatechuate (3943-89-3) + 1,3-dibromo-propane (109-64-8) → ethyl 3,4-dihydro-2H-benzo[b]1,4-dioxepine-7-carboxylate (20986-39-4)

Conditions	Yield
With potassium carbonate In ethanol for 5h; Reflux;	91%

Upstream product

• 99-50-3 3,4-Dihydroxybenzoic acid 
• 64-17-5 ethanol 
• 7647-01-0 hydrogenchloride 
• 120-47-8 Ethyl 4-hydroxybenzoate 
• 1344113-41-2 C₁₇H₂₈O₄Si 
• 20986-39-4 ethyl 3,4-dihydro-2H-benzo[b]1,4-dioxepine-7-carboxylate 
• 27214-71-7 cyanidin 3-O-glucopyranoside chloride 
• 3897-89-0 4-(hydroxymethyl)benzene-1,2-diol 
• 17159-79-4 ethyl 4-oxocyclohexane-1-carboxylate 
• 33668-25-6 ethyl 3-oxocyclohexanecarboxylate 
• 617-05-0 ethyl vanillate 
• 83759-00-6 3,4-dihydroxybenzoyl chloride 

Downstream Products

• 39635-11-5 3,4-dihydroxy-benzoic acid hydrazide 
• 74741-33-6 ethyl 2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-1,4-benzodioxan-6-carboxylate 
• 65479-39-2 2,6-dihydroxymethyl-3-(3,4-dimethoxyphenyl)-1,4-benzodioxan 
• 100100-77-4 (2RS,3RS)-2-(3,4-Dimethoxyphenyl)-3,6-bis(hydroxymethyl)-1,4-benzodioxan 
• 74741-37-0 (2S,3S)-2-(3,4-Dimethoxy-phenyl)-3-hydroxymethyl-2,3-dihydro-benzo[1,4]dioxine-6-carboxylic acid ethyl ester 
• 188564-63-8 ethyl 4-hydroxy-3-(phenylmethoxy)benzoate 
• 177429-27-5 ethyl 4-benzyloxy-3-hydroxybenzoate 
• 163163-70-0 ethyl 3-hydroxy-4-<<2-(1-imidazolyl)ethyl>oxy>benzoate 
• 185038-21-5 3,4-Bis-trifluoromethanesulfonyloxy-benzoic acid ethyl ester 
• 152361-07-4 2,2-Diphenyl-1,3-benzodioxolane-5-carboxylic acid, ethyl ester 
• 174398-83-5 ethyl 3,4-bis(benzyloxy)benzoate 
• 84955-24-8 3,4-Dibutoxy-benzoic acid ethyl ester 
• 111195-34-7 3,4-Bis-octyloxy-benzoic acid ethyl ester 
• 158921-40-5 ethyl 3,4-didecyloxybenzoate 

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