Monomethyl azelate
[CAS# 2104-19-0]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Carboxylic esters and their derivatives
• Name: Monomethyl azelate
• Synonyms: 9-methoxy-9-oxononanoic acid
• Molecular Formula: C₁₀H₁₈O₄
• Molecular Weight: 202.25
• CAS Registry Number: 2104-19-0
• EC Number: 218-275-2
• SMILES: COC(=O)CCCCCCCC(=O)O

Properties

• Density: 1.1±0.1 g/cm³ Calc.^*, 1.045 g/mL (Expl.)
• Melting point: 22 - 24 ºC (Expl.)
• Boiling point: 320.2 ºC 760 mmHg (Calc.)^*, 378.8 - 380.3 ºC (Expl.)
• Flash point: 111.7±16.7 ºC (Calc.)^*, 110 ºC (Expl.)
• Index of refraction: 1.452 (Calc.)^*, 1.446 (Expl.)

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319

Discovory and Applicatios

Monomethyl azelate is an organic compound classified as a monoalkyl ester of azelaic acid, also known as nonanedioic acid. Structurally, it consists of a linear nine-carbon dicarboxylic acid backbone in which one carboxylic acid group is esterified with a methyl group while the other remains as a free carboxylic acid. The molecular formula of monomethyl azelate is C₁₀H₁₈O₄, and it represents a key intermediate in both synthetic organic chemistry and industrial applications involving esters of aliphatic dicarboxylic acids.

The compound was first identified in the course of studies examining the partial esterification of dicarboxylic acids. Azelaic acid itself, originally derived from ozonolysis of oleic acid, was widely used in the production of esters for various industrial purposes. In the process of exploring derivatives of azelaic acid, chemists began synthesizing and isolating monoesters such as monomethyl azelate to study their chemical behavior and potential utility. The monoesterification typically involves controlled reaction of azelaic acid with a stoichiometric amount of methanol under acidic catalysis, often using sulfuric acid or p-toluenesulfonic acid, followed by purification through crystallization or distillation.

Monomethyl azelate has been used as an intermediate in the synthesis of more complex esters, amides, and polymer precursors. Its bifunctional nature—possessing both an ester group and a carboxylic acid group—makes it a valuable building block for chemical transformations that require selective reactivity at one functional group while maintaining the integrity of the other. In polymer chemistry, monomethyl azelate has been employed in the production of polyesters and polyamides through step-growth polymerization reactions. Its use enables the introduction of asymmetry and functional diversity into polymer chains, which can modify mechanical and thermal properties of the resulting materials.

In addition to synthetic uses, monomethyl azelate has been evaluated in the formulation of biodegradable lubricants and plasticizers. The presence of both polar and nonpolar regions in its structure provides favorable solvency and compatibility with various base fluids and polymer matrices. Its relatively high molecular weight and moderate polarity contribute to desirable viscosity and stability characteristics in experimental lubricant blends. Furthermore, because it is derived from azelaic acid—a compound that can be obtained from renewable sources—monomethyl azelate is often considered as a potential ingredient in environmentally friendly formulations.

Studies on esters of azelaic acid have also extended into biological and dermatological research. While monomethyl azelate itself has not been widely studied for pharmacological effects, its parent compound, azelaic acid, is known for antimicrobial and anti-inflammatory properties and is used in topical treatments for acne and rosacea. Derivatives such as monoesters have been synthesized and tested to evaluate their skin permeability and bioavailability, with monomethyl azelate included in comparative studies assessing how esterification alters physicochemical behavior. Such research has aimed to determine whether partial esterification improves dermal absorption or reduces irritation while retaining therapeutic activity.

The thermal and chemical stability of monomethyl azelate has made it suitable for mechanistic studies of ester hydrolysis and acid-catalyzed reactions. In kinetic experiments, the compound serves as a model substrate to evaluate the influence of chain length, substitution, and reaction conditions on the rate and pathway of ester cleavage. Data derived from such studies contribute to understanding reaction mechanisms involving esters under physiological and industrial conditions.

Monomethyl azelate continues to be referenced in chemical databases and industrial catalogs as a specialty chemical with applications in polymer science, material synthesis, and formulation chemistry. Its dual functionality and relative ease of synthesis from a renewable precursor maintain its status as a useful compound in both research and applied settings.

References

2017. Oxidation of Renewables. Homogeneous Catalysis with Renewables.
DOI: 10.1007/978-3-319-54161-7_6

1993. On the syntheses of branched saturated fatty acids. Lipids, 28(10).
DOI: 10.1007/bf02537496

1988. Synthesis of azelaic acid and suberic acid from Vernonia galamensis oil. Journal of the American Oil Chemists' Society, 65(11).
DOI: 10.1007/bf02542380