4-Picolinic acid methyl ester (methyl isonicotinate, methyl pyridine-4-carboxylate), CAS 2459-09-8, is a colourless to light yellow liquid ester used as a pharmaceutical and agrochemical building block. It is the standard starting material for isoniazid and for pyridine-4-carboxamide derivatives, and it is supplied at purity 98% min with water 0.5% max – the moisture limit matters because the ester hydrolyses back to isonicotinic acid. PolyBlueChem supplies it in drums and IBCs with per-batch COA and SDS.
Specifications
| Property | Specification |
|---|---|
| Appearance | Colourless to light yellow liquid |
| Purity (GC, %) | Min 98 |
| Water (%) | Max 0.5 |
| Packaging | 200 kg drum; 1000 kg IBC on request |
Basic Information
| Chemical name | Methyl pyridine-4-carboxylate (methyl isonicotinate) |
| Common names | 4-Picolinic acid methyl ester, methyl isonicotinate, isonicotinic acid methyl ester |
| CAS number | 2459-09-8 |
| Chemical class | Pyridinecarboxylate ester (heteroaromatic ester) |
| Appearance | Colourless to light yellow liquid |
| Purity | Min 98% (GC) |
| Water | Max 0.5% |
| Typical use | Pharmaceutical and agrochemical intermediate |
Where It Fits in Synthesis
The molecule is a pyridine ring carrying a methyl ester at the 4-position. That single functional group is the reason it is bought in tonne quantities: an ester at that position reacts cleanly with nitrogen nucleophiles, which is how the 4-carboxamide and 4-carbohydrazide families are made.
- With hydrazine hydrate it gives isonicotinyl hydrazide (isoniazid) – the classic antitubercular active pharmaceutical ingredient, produced industrially by this route.
- With ammonia or amines it gives isonicotinamide and N-substituted amides.
- By hydrolysis it returns to isonicotinic acid, which is why the water specification is a real quality parameter rather than a formality.
- As a ligand precursor pyridine-4-carboxylate esters appear in coordination chemistry and in the synthesis of functional pyridine derivatives.
Handling and Storage
| Point | Guidance |
|---|---|
| Moisture | Keep drums closed; the ester hydrolyses in the presence of water, especially warm or acidic conditions |
| Storage | Cool, dry, ventilated area away from acids, bases and oxidisers; protect from direct sunlight |
| Handling | Use gloves and eye protection; work under local exhaust ventilation because the liquid has a pyridine-type odour |
| Material compatibility | Stainless steel or high-density polyethylene drums; avoid prolonged contact with acidic residues in reused containers |
Packaging and Documentation
Supplied in 200 kg polyethylene or stainless steel drums, with 1000 kg IBC available on request. Each batch is released against a COA covering appearance, assay by GC and water content; SDS is available in English. For pharmaceutical use, additional documentation such as residual solvent and elemental impurity statements can be arranged at enquiry stage – specific regulatory claims are confirmed per destination market rather than assumed from a generic datasheet.
Related reading
- Methyl isonicotinate (4-picolinic acid methyl ester): properties, production and applications
- Methyl isonicotinate in isoniazid and pyridine-4-carboxamide synthesis
- 2-Chloronicotinic acid: chemistry, production and applications
FAQ
What is the CAS number of 4-picolinic acid methyl ester? CAS 2459-09-8 (methyl isonicotinate).
Why is a water limit specified? Esters hydrolyse. Moisture above the 0.5% limit means part of the batch has already reconverted to isonicotinic acid, which changes both the assay and the downstream hydrazide reaction.
Is it the same as isonicotinic acid? No. Isonicotinic acid is the free carboxylic acid; this product is its methyl ester.
How is it supplied? 200 kg drums, or 1000 kg IBC on request, each batch with COA and SDS.
Contact PolyBlueChem for specifications, samples and quotations.
