3-Methyl-4-nitrobenzoic acid Property

Melting point:

216-218 °C (lit.)

Boiling point:

314.24°C (rough estimate)

Density 

1.4283 (rough estimate)

refractive index 

1.5468 (estimate)

storage temp. 

Sealed in dry,Room Temperature

solubility 

slightly sol. in Alcohol

pka

3.49±0.10(Predicted)

form 

Amorphous Powder

color 

Yellow

Water Solubility 

<0.1 g/100 mL at 22 ºC

BRN 

1959154

InChIKey

XDTTUTIFWDAMIX-UHFFFAOYSA-N

CAS DataBase Reference

3113-71-1(CAS DataBase Reference)

NIST Chemistry Reference

3-Methyl-4-nitrobenzoic acid(3113-71-1)

EPA Substance Registry System

3-Methyl-4-nitrobenzoic acid (3113-71-1)

Safety

Hazard Codes 

Xi,Xn

Risk Statements 

36/37/38-20/21/22

Safety Statements 

26-36-36/37/39-22

WGK Germany 

3

Hazard Note 

Irritant

TSCA 

Yes

HS Code 

29163900

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P405Store locked up.

3-Methyl-4-nitrobenzoic acid Chemical Properties,Usage,Production

Description

In organic synthesis, 3-Methyl-4-nitrobenzoic acid (abbreviated as MNBA)  is the fine chemical product that adds value is higher; many critical organic products are obtained for raw material can synthesize further with it, as 4-chloro-quinazoline-6-ethyl formate, 2-n-propyl-4-methyl-6-carboxy benzimidazole, 4-methyl-2-ethyl-1H-benzoglyoxaline-6-methyl-formiate, 3,4-dihydro-4-quinazoline is with-6-formic acid, 4-aminophenyl-1,3-dioctyl phthalate, 4-Amino-3-methylbenzoic acid methyl esters, 4-nitrophenyl-1,3-dioctyl phthalate etc. In medicine, it is an essential intermediate in the synthesis of telmisartan (via esterification, reduction, butyrylation, nitration, reduction and cyclization), which is used to treat essential hypertension. Telmisartan is a drug belonging to the group of antagonists of angiotensin II receptors. The active ingredient telmisartan counteracts the effect of angiotensin II, allowing the arteries to relax, thereby reducing blood pressure. As a precursor, pharmaceutical researchers have also synthesized anti-cancer substances and AIDS drugs with MNBA[1].

Chemical Properties

white to light yellow crystal powder

Uses

3-Methyl-4-nitrobenzoic Acid is used as a reagent in the synthesis of influenza neuraminidase inhibitors with pyrrolidinobenzoic acid scaffold containing lipophilic side chains.

Preparation

3-Methyl-4-nitrobenzoic acid was synthesized via oxidation of 2,4-(dimethylnitrobenzene) with mole-(cular) oxygen catalyzed by cobalt acetate in acetic acid in the presence of an initiator.It was found that the yield of 3-methyl-4-nitrobenzoic acid increased remarkably with the addition of sodium bromide as a co-(catalyst).The reaction was carried out at 130 ℃ for 8 h at 0.8 MPa of oxygen in the presence of 0.017 mol of cobalt acetate,(0.017 mol) of sodium bromide,and 0.30 mol of 2-butanone with 1.00 mole of 2,4-dimethylnitrobenzene.(Under) these conditions 99% of the reactant converted with a selectivity of 52% to 3-methyl-4-(nitrobenzoic) acid,and the yield of 3methyl-4-(nitrobenzoic) acid was 51%.The reaction mechanism and the function of(sodium) bromide were discussed.According to the fact that the reaction could not proceed without the presence of an initiator,it was proposed that the reaction took place via a free radical mechanism,and(sodium) bromide reacted with Co(Ⅲ) to generate bromine radicals,which promoted the formation of benzyl radicals.
Synthesis of 3-Methyl-4-nitrobenzoic Acid via Catalytic Oxidation with Molecular Oxygen
Method for preparing 3-methyl-4-nitrobenzoic acid by oxidizing with nitric acid

General Description

Needles or off white powder.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

3-Methyl-4-nitrobenzoic acid is a nitrated carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry.

Fire Hazard

Flash point data for 3-Methyl-4-nitrobenzoic acid are not available; however, 3-Methyl-4-nitrobenzoic acid is probably combustible.

References

[1] Yüfang Wu. “Solubility of 3-methyl-4-nitrobenzoic acid in binary solvent mixtures of {(1,4-dioxane, N-methyl-2-pyrrolidone, N,N-dimethylformamide) methanol} from T = (283.15 to 318.15) K: Experimental determination and thermodynamic modelling.” Journal of Chemical Thermodynamics 105 (2017): Pages 165-172.