3,4-Dichlorobenzoic acid

CAS NO.：51-44-5
Empirical Formula: C7H4Cl2O2
Molecular Weight: 191.01
MDL number: MFCD00002492
EINECS: 200-099-2
SAFETY DATA SHEET (SDS)
Update Date: 2026-05-28 02:15:41

What is 3,4-Dichlorobenzoic acid?

Chemical properties

White to light yellow crystal powder

The Uses of 3,4-Dichlorobenzoic acid

3,4-Dichlorobenzoic acid was employed as internal standard during the multiresidue analysis of pharmaceuticals and personal care products by ultra performance liquid chromatography-positive/negative electrospray tandem mass spectrometry. It was used to study the metabolic fate of 4-chloro-3,5-dinitrobenzoic acid.

Definition

ChEBI: A chlorobenzoic acid carrying chloro substituents at positions 3 and 4.

Synthesis Reference(s)

Journal of the American Chemical Society, 98, p. 843, 1976 DOI: 10.1021/ja00419a038

Safety Profile

Poison by subcutaneous route. When heated to decomposition it emits toxic fumes of Cl-.

Purification Methods

Crystallise the acid from aqueous EtOH (charcoal) or acetic acid. [Beilstein 9 IV 1006.] Aromatic acid impurities (to <0.05%) can be removed via the (±)--methylbenzylamine salt as described for 2,4-dichlorobenzoic acid [Ley & Yates Organic Process Research & Development 12 120 2008.]

Properties of 3,4-Dichlorobenzoic acid

Melting point:	204-206 °C (lit.)
Boiling point:	273.68°C (rough estimate)
Density	1.4410 (rough estimate)
refractive index	1.4590 (estimate)
storage temp.	Sealed in dry,Room Temperature
form	powder to crystal
pka	3.60±0.10(Predicted)
color	White to Almost white
Water Solubility	insoluble
BRN	2044777
CAS DataBase Reference	51-44-5(CAS DataBase Reference)
NIST Chemistry Reference	Benzoic acid, 3,4-dichloro-(51-44-5)
EPA Substance Registry System	3,4-Dichlorobenzoic acid (51-44-5)

Safety information for 3,4-Dichlorobenzoic acid

Signal word	Warning
Pictogram(s)	Exclamation Mark Irritant GHS07
GHS Hazard Statements	H315:Skin corrosion/irritation H319:Serious eye damage/eye irritation H335:Specific target organ toxicity, single exposure;Respiratory tract irritation
Precautionary Statement Codes	P261:Avoid breathing dust/fume/gas/mist/vapours/spray. P264:Wash hands thoroughly after handling. P264:Wash skin thouroughly 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. Continuerinsing.