N,N-Dimethyl-p-toluidine: Properties, Safety & Lab Use Guide

N,N-Dimethyl-p-toluidine is a tertiary aromatic amine (CAS 99-97-8) valued in research and industrial laboratories for its role as a radical polymerization accelerator, redox co-initiator, and versatile intermediate in organic synthesis.

CAS Number

99-97-8

Molecular Formula

C9H13N

Molecular Weight

135.21 g/mol

Appearance

Colorless to pale yellow liquid

Primary Use

Accelerator for radical polymerization; organic synthesis intermediate

Storage Condition

Store in a cool, well-ventilated area, away from oxidizers and ignition sources

Aladdin SKU

N661236

Physicochemical Properties

N,N-Dimethyl-p-toluidine (DMPT) is a tertiary aromatic amine with the molecular formula C₉H₁₃N and a molecular weight of 135.21 g/mol. It consists of a toluene ring bearing a dimethylamino group at the para position. At room temperature it is a colorless to pale yellow liquid with a characteristic amine odor.

Key physicochemical parameters (textbook-level reference values; verify against certificate of analysis):

• Boiling point: approximately 210–212 °C at 760 mmHg
• Density: approximately 0.937 g/mL at 25 °C
• Refractive index (n_D²⁰): approximately 1.556
• Flash point: approximately 82 °C (closed cup)
• Solubility: miscible with common organic solvents (ethanol, acetone, toluene); sparingly soluble in water

The electron-donating dimethylamino group activates the aromatic ring toward electrophilic substitution and renders the nitrogen highly nucleophilic, underpinning its reactivity as an accelerator and synthetic building block.

Laboratory Applications

N,N-Dimethyl-p-toluidine serves several important roles in research and applied chemistry:

1. Radical polymerization accelerator: DMPT is widely employed as a redox co-initiator alongside benzoyl peroxide (BPO) in free-radical polymerization systems, particularly for acrylic bone cements, dental resins, and polymer composites. It reduces the decomposition temperature of the peroxide initiator, enabling room-temperature curing.
2. Organic synthesis intermediate: The compound acts as a building block in the preparation of dyes, pharmaceuticals, and agrochemical intermediates. Its activated aromatic ring undergoes diazonium coupling, electrophilic halogenation, and other transformations.
3. Analytical reagent: DMPT has been used in colorimetric and spectrophotometric assays exploiting its reactivity with oxidizing species.
4. Ligand precursor: In coordination chemistry, dimethylaminotoluene derivatives serve as ligand precursors for transition-metal catalysis research.

Aladdin Scientific supplies N,N-Dimethyl-p-toluidine (SKU N661236) in 1 mL research-scale quantities suitable for exploratory synthesis and method development.

Safe Handling and Storage

N,N-Dimethyl-p-toluidine is a hazardous chemical requiring careful handling in accordance with applicable SDS guidelines. Researchers should observe the following precautions:

Personal Protective Equipment (PPE)

• Wear chemical-resistant gloves (nitrile or neoprene), safety goggles, and a laboratory coat at all times.
• Use in a well-ventilated fume hood to prevent inhalation of vapors.
• Avoid skin contact; the compound can be absorbed through the skin and may cause methemoglobinemia at significant exposures.

Storage

• Store in a tightly sealed container in a cool, dry, well-ventilated area (recommended: 2–8 °C or ambient cool storage per SDS).
• Keep away from strong oxidizing agents, strong acids, and ignition sources.
• Protect from light to minimize discoloration and degradation.

Waste Disposal

• Dispose of according to local regulations for hazardous organic amine waste. Do not pour down the drain.

Always consult the current Safety Data Sheet (SDS) before use. Specific hazard classifications and first-aid measures are detailed therein.

Quality, Purity, and Specifications

For reliable experimental results, the purity and specification of N,N-Dimethyl-p-toluidine are critical parameters. Aladdin Scientific's N661236 is a research-grade reagent supplied in a 1 mL format.

When evaluating this or any aromatic amine reagent, key specification parameters to confirm include:

• Purity (GC): Typically ≥98% or ≥99% for research-grade material; confirm on the certificate of analysis (CoA).
• Identity confirmation: Verified by GC-MS or NMR spectroscopy.
• Appearance: Should be a clear, colorless to pale yellow liquid free of visible particulates.
• Water content: Low moisture content is preferred for moisture-sensitive applications; check Karl Fischer data if relevant.

Researchers should request the CoA for each lot to verify that the material meets their experimental requirements before use in critical assays or formulations.

Frequently asked questions

What is N,N-Dimethyl-p-toluidine primarily used for in the laboratory?

N,N-Dimethyl-p-toluidine (DMPT) is most commonly used as a redox co-initiator and accelerator for free-radical polymerization systems, particularly in combination with benzoyl peroxide for room-temperature curing of acrylic resins and bone cements. It is also used as an intermediate in organic synthesis for the preparation of dyes, pharmaceuticals, and agrochemical compounds.

How should N,N-Dimethyl-p-toluidine be stored to maintain its quality?

Store N,N-Dimethyl-p-toluidine in a tightly sealed container in a cool, dry, well-ventilated location, away from strong oxidizing agents, strong acids, and sources of ignition. Protection from light is recommended to prevent discoloration and degradation. Always follow the storage conditions specified in the current Safety Data Sheet and the product's certificate of analysis.

What safety precautions are required when handling N,N-Dimethyl-p-toluidine?

Handlers should wear chemical-resistant gloves (nitrile or neoprene), safety goggles, and a laboratory coat, and should work exclusively in a well-ventilated fume hood to avoid vapor inhalation. Skin contact must be avoided, as the compound can be dermally absorbed and may cause methemoglobinemia at significant exposure levels. Consult the full Safety Data Sheet for hazard classifications, first-aid measures, and disposal requirements before use.

What purity grade is Aladdin's N,N-Dimethyl-p-toluidine (SKU N661236)?

SKU N661236 is a research-grade reagent supplied in a 1 mL format. For specific purity values, identity confirmation methods, and lot-specific data, researchers should consult the certificate of analysis (CoA) available from Aladdin Scientific, as specifications may vary by production lot.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (General reference for aromatic amine chemistry.)
2. Brydson, J. A. Plastics Materials, 7th ed.; Butterworth-Heinemann: Oxford, 1999. (Reference for DMPT as polymerization accelerator in acrylic systems.)
3. Sigma-Aldrich / Merck. Safety Data Sheet: N,N-Dimethyl-p-toluidine, CAS 99-97-8. (Accessed for physicochemical and hazard reference data.)

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.