N,N,4-Trimethylaniline

We want to confirm the naming here precisely, since it's easy to misread: in "N,N,4-Trimethylaniline," the "4" refers to a ring methyl group positioned para (at the 4-position) to the ring carbon carrying the N,N-dimethylamino group — this is the same compound as N,N-dimethyl-p-toluidine, the para-substituted isomer, not an ortho- or meta-toluidine derivative. We verified this mapping against an ECHA Risk Assessment Committee document and standard IUPAC nomenclature rules before using it on this page.

This compound's most specifically and officially documented commercial use — more specifically sourced, in fact, than the broadly similar claim made for N,N-Dimethylaniline elsewhere in this range — is as a hardener/accelerator in acrylic (PMMA) resin systems used in dental fillings and bone-cement adhesives, confirmed directly in an ECHA RAC document. It is also used as a polymerisation accelerator in polyester and epoxy resin systems more broadly, and as an intermediate in photographic chemicals, dyes and medicines, though specific named products in those last three categories were not found in the sources we checked.

Where it fits in the synthesis chain

We supply N,N,4-Trimethylaniline itself as an accelerator and intermediate. We do not manufacture or supply finished dental materials, bone cements, cured resins, or any dye, photographic chemical or medicine made using it.

Grades we supply

99%+ is the standard commercial accelerator-grade offering.

N,N,4-Trimethylaniline is made by N,N-dialkylation of p-toluidine with methanol or methyl halide under acid catalysis or pressure — the same general dialkylation strategy used for N,N-Dimethylaniline, applied to the ring-methylated toluidine starting material instead of plain aniline.

We want to be honest that we did not find this exact route explicitly documented in a primary source during this research pass; it is the chemically standard, expected analogue to the well-documented N,N-Dimethylaniline manufacturing route, and we present it on that basis.

The crude product is purified by distillation to separate it from unreacted p-toluidine and partially methylated intermediates, then tested for purity and colour before release, since accelerator-grade buyers in the dental and resin trade specify tight purity to ensure consistent, predictable cure performance.

A hazard classification genuinely in transition — flagged, not settled

This is worth stating carefully rather than simplifying. This compound currently sits under an existing EU Annex VI group entry covering toluidine isomers generally. We located an ECHA Risk Assessment Committee opinion proposing a new, substance-specific Annex VI entry with a considerably more severe classification — Carcinogen Category 1B (H350) among other statements — and a separate EU Council document referencing this compound for addition to a REACH Annex XVII consumer-product restriction list. As of this page's most recent review, we could not confirm these proposals have been formally adopted into EU law; we treat the stricter classification as pending, not yet in force, and recommend checking ECHA's current C&L Inventory before relying on a specific hazard statement. Separately, and already in force today rather than pending, California's Proposition 65 lists this compound as a carcinogen (since May 2014).