2-Methylhydroquinone
[CAS# 95-71-6]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyridine compound >> Fluoropyridine
• Name: 2-Methylhydroquinone
• Synonyms: 2,5-Dihydroxytoluene; 2-Methyl-1,4-benzenediol; Toluhydroquinone; THQ
• Molecular Formula: C₇H₈O₂
• Molecular Weight: 124.14
• CAS Registry Number: 95-71-6 (96937-50-7)
• EC Number: 202-443-7
• SMILES: CC1=C(C=CC(=C1)O)O

Properties

• Water solubility: 77 g/L (25 ºC)
• Density: 1.2±0.1 g/cm³, Calc.^*
• Melting point: 125-128 ºC
• Index of Refraction: 1.595, Calc.^*
• Boiling Point: 277.8±20.0 ºC (760 mmHg), Calc.^*, 285 ºC
• Flash Point: 140.2±16.4 ºC, Calc.^*, 172 ºC

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS08;GHS09 Danger
• Hazard Statements: H302-H315-H317-H318-H319-H335-H341-H351-H400-H410
• Precautionary Statements: P203-P261-P264-P264+P265-P270-P271-P272-P273-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P318-P319-P321-P330-P332+P317-P333+P317-P337+P317-P362+P364-P391-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Skin irritation	Skin Irrit.	2	H315
Germ cell mutagenicity	Muta.	2	H341
Carcinogenicity	Carc.	2	H351
Serious eye damage	Eye Dam.	1	H318
Eye irritation	Eye Irrit.	2	H319
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Skin corrosion	Skin Corr.	1A	H314
Acute toxicity	Acute Tox.	4	H312
Acute toxicity	Acute Tox.	3	H301
Acute toxicity	Acute Tox.	4	H332

Discovory and Applicatios

2-Methylhydroquinone, also known as 2-methyl-1,4-benzenediol, is an organic compound characterized by a benzene ring with two hydroxyl groups (-OH) positioned at the 1 and 4 carbon atoms, with a methyl group (-CH3) at the 2 position. This compound is a structural isomer of hydroquinone and has gained interest in various chemical applications since its discovery in the early 20th century. The synthesis of 2-methylhydroquinone can be achieved through several methods, including the reduction of 2-methylbenzoquinone or through the catalytic hydrogenation of ortho- or para-nitrotoluene.

The primary application of 2-methylhydroquinone is as an antioxidant in various industrial processes. Its chemical structure allows it to act as a radical scavenger, effectively preventing oxidative degradation in products such as plastics, rubber, and cosmetics. This property is particularly important in preserving the stability and shelf life of these materials, ensuring their performance and safety in consumer products.

In addition to its role as an antioxidant, 2-methylhydroquinone serves as a precursor in the synthesis of various pharmaceuticals and fine chemicals. Its ability to undergo further chemical transformations allows for the development of compounds with diverse biological activities. For instance, derivatives of 2-methylhydroquinone have been explored for their potential anti-inflammatory and antimicrobial properties, making them candidates for drug development in the pharmaceutical industry.

Moreover, 2-methylhydroquinone is utilized in the synthesis of dyes and pigments. Its structure provides a basis for creating colored compounds, which are valuable in the textile and paint industries. The compound's reactivity facilitates the formation of azo dyes and other colorants, contributing to its significance in these applications.

Despite its beneficial uses, 2-methylhydroquinone poses safety considerations that must be addressed. Like many phenolic compounds, it can be irritating to the skin and eyes and may have toxic effects if ingested or inhaled. Regulatory agencies have established guidelines for its safe handling in industrial processes to minimize health risks. Proper safety measures, such as personal protective equipment and adequate ventilation, are essential when working with this compound.

Recent research has also begun to focus on the environmental impact of 2-methylhydroquinone and its derivatives. Efforts are being made to explore greener synthesis methods and alternative compounds that can provide similar functions while reducing environmental harm. This shift towards sustainability reflects a broader commitment within the chemical industry to address ecological concerns.

In conclusion, 2-methylhydroquinone is an important compound with significant applications in antioxidant production, pharmaceuticals, and dye synthesis. Its discovery has contributed to advancements in these fields, though safety and environmental considerations must remain a priority. Ongoing research aims to enhance its applications while promoting sustainable practices in its use.

References

2023. Potential of the enzyme laccase for the synthesis and derivatization of antimicrobial compounds. World Journal of Microbiology and Biotechnology, 39(3).
DOI: 10.1007/s11274-023-03539-x

2024. Holographic Polymer Nanocomposites with High Refractive Index Modulation by Doping Liquid Crystal E6M. Chinese Journal of Polymer Science, 42(4).
DOI: 10.1007/s10118-024-3110-z

2023. Proliferation Inhibitory Activity of Quinones from Blaps rynchopetera Defense Secretion on Colorectal Tumor Cells. Chinese Journal of Integrative Medicine, 29(4).
DOI: 10.1007/s11655-023-3696-y