3-Methyl-4-chlorophenyl isocyanate
[CAS# 51488-20-1]

Identification

• Classification: Chemical reagent >> Organic reagent >> Cyanate ester / isocyanate
• Name: 3-Methyl-4-chlorophenyl isocyanate
• Synonyms: 4-Chloro-3-methylphenyl isocyanate; 4-Chloro-m-tolyl isocyanate
• Molecular Formula: C₈H₆ClNO
• Molecular Weight: 167.59
• CAS Registry Number: 51488-20-1
• EC Number: 641-286-2
• SMILES: CC1=C(C=CC(=C1)N=C=O)Cl

Properties

• Density: 1.2±0.1 g/cm³ Calc.^*
• Boiling point: 243.8±20.0 °C 760 mmHg (Calc.)^*
• Flash point: 92.1±11.0 °C (Calc.)^*
• Index of refraction: 1.544 (Calc.)^*

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

Safety Data

• Hazard Symbols: GHS06;GHS07;GHS08 Danger
• Risk Statements: H301-H311-H315-H319-H330-H331-H334-H335
• Safety Statements: P233-P260-P261-P262-P264-P264+P265-P270-P271-P280-P284-P301+P316-P302+P352-P304+P340-P305+P351+P338-P316-P319-P320-P321-P330-P332+P317-P337+P317-P342+P316-P361+P364-P362+P364-P403-P403+P233-P405-P501

Discovery and Applications

3-Methyl-4-chlorophenyl isocyanate is an organic compound belonging to the isocyanate chemical family, characterized by the presence of the isocyanate functional group (-N=C=O) attached to a substituted aromatic ring. Specifically, this compound features a methyl group at the 3-position and a chlorine atom at the 4-position of the phenyl ring. The isocyanate group confers high reactivity, making this compound useful in various chemical synthesis applications.

The discovery and characterization of 3-methyl-4-chlorophenyl isocyanate align with broader research on aromatic isocyanates that began in the early 20th century. Isocyanates are generally synthesized through the reaction of amines with phosgene or related reagents, enabling the formation of the reactive isocyanate group. The introduction of substituents such as methyl and chloro groups on the phenyl ring allows modification of the compound’s reactivity and physical properties, broadening its utility.

This compound is predominantly used as an intermediate in organic synthesis. Its reactivity toward nucleophiles, especially amines and alcohols, allows it to participate in the formation of ureas, carbamates, and other derivatives. These reactions are important in the manufacture of pharmaceuticals, agrochemicals, and polymer materials. In particular, substituted phenyl isocyanates serve as key building blocks in the preparation of compounds with desired biological or material properties.

Due to the presence of the isocyanate group, 3-methyl-4-chlorophenyl isocyanate is highly reactive and requires careful handling. It is typically stored under controlled conditions to prevent hydrolysis or unwanted side reactions. The compound can react with water or moisture to produce amines and carbon dioxide, which has implications for its stability during storage and use.

In polymer chemistry, isocyanates such as 3-methyl-4-chlorophenyl isocyanate are valuable for synthesizing polyurethanes and related polymers. These materials have wide applications in coatings, adhesives, foams, and elastomers. Although this specific compound may not be the primary isocyanate used industrially for large-scale polyurethane production, its structural features make it a useful model compound or intermediate in research and development of novel polymer systems.

In pharmaceutical chemistry, derivatives of substituted phenyl isocyanates have been investigated for their potential as enzyme inhibitors, herbicides, and antimicrobial agents. The ability to fine-tune the substituent pattern on the aromatic ring allows for optimization of biological activity and pharmacokinetic properties in drug design.

The handling and use of 3-methyl-4-chlorophenyl isocyanate are subject to safety regulations due to its potential health hazards. Exposure to isocyanates can cause respiratory sensitization and skin irritation, so protective measures such as proper ventilation and personal protective equipment are necessary in laboratory and industrial settings.

In summary, 3-methyl-4-chlorophenyl isocyanate is a chemically reactive aromatic isocyanate used primarily as an intermediate in organic synthesis. Its structural features enable applications in the preparation of pharmaceuticals, agrochemicals, and polymeric materials. The compound’s reactivity demands careful handling to ensure safety and stability during its use.

References

2015. Engineering Cyclodextrin Clicked Chiral Stationary Phase for High-Efficiency Enantiomer Separation. Scientific Reports, 5.
DOI: 10.1038/srep11523