Benzofuran-5-carboxylic acid RC00160

Manufacturer: Hangzhou Royalchem Co.,LTD.

Website:  www.cnroyalchem.com

Product Name:  Benzofuran-5-carboxylic Acid
Synonyms:

5-Benzofurancarboxylic Acid

Benzofuran-5-carboxylic Acid

1-Benzofuran-5-carboxylic Acid

5-Carboxybenzofuran  CAS Number:  90721-27-0
Molecular Formula:  C₉H₆O₃
Molecular Weight:  162.14 g/mol
Beilstein Registry Number:  117813
EC Number:  636-218-4

Chemical Structure:
[Visual representation typically shows the fused benzene and furan rings with a carboxylic acid (-COOH) group attached to carbon 5 of the benzofuran system].
Melting Point:  Approximately 218-222 °C (literature values may vary slightly).
Solubility:

Soluble in:  Common organic solvents such as Dimethylformamide (DMF), Dimethyl Sulfoxide (DMSO), Methanol, Ethanol (especially with mild heating), Acetonitrile, Tetrahydrofuran (THF), Chloroform, Dichloromethane (DCM).

Sparingly soluble or Insoluble in:  Water, Hexane, Diethyl ether. 

Key Chemical Properties:

Functional Groups:  Contains both a benzofuran heterocyclic system (fused benzene and furan rings) and a carboxylic acid group.

Acidity:  Behaves as a typical carboxylic acid (pKa ~4-5), capable of forming salts (e.g., sodium, potassium salts) which are generally more water-soluble.

Reactivity:  The carboxylic acid group readily undergoes reactions typical for aromatic carboxylic acids:

Esterification (formation of methyl, ethyl esters, etc.).

Amidation (formation of amides, primary or secondary).

Reduction (to aldehydes or alcohols).

Conversion to acid chlorides (using reagents like SOCl₂, oxalyl chloride).

Decarboxylation (under specific conditions). 

Heterocyclic Core:  The benzofuran moiety itself can participate in electrophilic aromatic substitution reactions, although the electron-deficient nature compared to benzene and the directing effects of the furan oxygen and existing carboxylic acid group influence reactivity.

Spectral Data (Typical):

IR (KBr, cm⁻¹):  Broad O-H stretch (~2500-3300), strong C=O stretch (~1680-1720), C=C aromatic stretches (~1400-1600), C-O stretches (~1200-1300).

¹H NMR (DMSO-d₆, δ ppm):  ~8.00-8.15 (d, 1H, H-4), ~7.80-7.90 (dd, 1H, H-7), ~7.65-7.75 (d, 1H, H-6), ~7.50-7.60 (d, 1H, H-2), ~6.80-7.00 (d, 1H, H-3), broad ~12-13 (COOH, often exchangeable). 

¹³C NMR (DMSO-d₆, δ ppm):  Characteristic peaks including carbonyl carbon @ ~165-168 ppm, aromatic carbons between ~110-155 ppm.

Storage Conditions:

Store in a cool, dry, well-ventilated place.

Keep container tightly closed.

Protect from moisture and light.

Recommended storage temperature: 2-8 °C (refrigerated) or room temperature for short term, depending on supplier stability data.

Handling Precautions:

Hazard Statements (H Statements):  Typically includes:

H315: Causes skin irritation.

H319: Causes serious eye irritation.

H335: May cause respiratory irritation.

Precautionary Statements (P Statements):  Typically includes:

P261: Avoid breathing dust/fume/gas/mist/vapours/spray.

P264: Wash hands thoroughly after handling.

P271: Use only outdoors or in a well-ventilated area.

P280: Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352: IF ON SKIN: Wash with plenty of soap and water.

P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.

Personal Protective Equipment (PPE):  Use chemical safety goggles, gloves (e.g., nitrile), and lab coat. Adequate ventilation (e.g., fume hood) is essential. Respiratory protection may be required if dust generation is significant.

Incompatibilities:  Strong oxidizing agents, strong bases.

Applications:
Benzofuran-5-carboxylic acid is primarily used as a  key building block or intermediate  in organic synthesis, particularly in the pharmaceutical and agrochemical industries. Its applications include:

Synthesis of pharmaceutical candidates targeting various diseases.

Preparation of biologically active amides and esters.

Development of ligands for medicinal chemistry.

Construction of more complex heterocyclic systems incorporating the benzofuran scaffold.

Material science research.