Definition
Methyl nicotinate, also known as methyl 3‑pyridinecarboxylate, is the methyl ester of nicotinic acid (niacin). Its chemical formula is C₇H₇NO₂ and it has a molar mass of approximately 137.14 g·mol⁻¹. The compound is listed under CAS Number 104‑01‑2.
Overview
Methyl nicotinate is a colourless to pale‑yellow liquid with a characteristic pyridine‑like odour. It is used primarily as a fragrance ingredient in cosmetics and personal‑care products and as a topical vasodilator that produces a transient warming sensation on the skin. In pharmaceutical formulations, it is employed to enhance local blood flow, which can aid in the delivery of other active agents. The compound is also of interest in organic synthesis as an intermediate for the preparation of pyridine‑based polymers and heterocyclic derivatives.
Etymology / Origin
The name “nicotinate” derives from nicotinic acid, itself named after nicotine, the alkaloid first isolated from tobacco (Nicotiana spp.). The prefix “methyl‑” denotes the presence of a methyl (CH₃) group esterifying the carboxylic acid function of nicotinic acid, yielding the methyl ester.
Characteristics
| Property | Value / Description |
|---|---|
| Molecular formula | C₇H₇NO₂ |
| Molar mass | ≈ 137.14 g·mol⁻¹ |
| Physical state | Liquid at room temperature |
| Colour | Colourless to pale yellow |
| Odour | Pyridine‑like |
| Melting point | –6 °C (approx.) |
| Boiling point | 226 °C (at 760 mm Hg) |
| Density | ~1.10 g·cm⁻³ at 20 °C |
| Solubility | Slightly soluble in water; miscible with most organic solvents (e.g., ethanol, ether, chloroform) |
| pKa (of conjugate acid) | ≈ 5.0 (for the nicotinic acid moiety) |
| Spectroscopic data | ^1H NMR: signals consistent with a pyridine ring and a methoxy group; IR: strong C=O stretch near 1730 cm⁻¹, characteristic aromatic C–H bands. |
Biological and practical effects
- Vasodilation – Application to the skin produces localized vasodilation, leading to a warming sensation that is exploited in topical pain‑relief and “rub” products.
- Irritation potential – The compound can be a mild skin and respiratory irritant at higher concentrations; safety data sheets recommend handling with appropriate protective equipment.
- Fragrance profile – Provides a subtle, crisp note used in perfumes, aftershaves, and scented lotions.
Related Topics
- Nicotinic acid (niacin) – The parent carboxylic acid from which methyl nicotinate is derived.
- Pyridine derivatives – A broad class of heterocyclic compounds that includes methyl nicotinate and many pharmacologically active agents.
- Esters – Organic compounds formed by the condensation of an acid and an alcohol; methyl nicotinate is a simple aromatic ester.
- Topical vasodilators – Substances such as menthol, capsaicin, and methyl nicotinate that induce local vasodilation and sensory effects.
- Cosmetic fragrance ingredients – Methyl nicotinate is listed among approved fragrance materials used in personal‑care formulations.