Dimethyl heptanedioate
[CAS# 1732-08-7]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Carboxylic esters and their derivatives
• Name: Dimethyl heptanedioate
• Synonyms: 1OV5VO1; 1,7-dimethyl heptanedioate; Dimethyl pimelate
• Molecular Formula: C₉H₁₆O₄
• Molecular Weight: 188.22
• CAS Registry Number: 1732-08-7
• EC Number: 217-057-4
• SMILES: COC(=O)CCCCCC(=O)OC

Properties

• Density: 1.0±0.1 g/cm³ Calc.^*, 1.041 g/mL (Expl.)
• Melting point: -21 ºC (Expl.)
• Boiling point: 250.3 ºC 760 mmHg (Calc.)^*, 276.9 - 278.2 ºC (Expl.)
• Flash point: 105.4±16.9 ºC (Calc.)^*, 110 ºC (Expl.)
• Index of refraction: 1.427 (Calc.)^*, 1.431 (Expl.)

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

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P305+P351+P338

Discovory and Applicatios

Dimethyl heptanedioate, also known as dimethyl pimelate, is an organic compound with the molecular formula C₉H₁₆O₄. It belongs to the class of dialkyl esters derived from heptanedioic acid (also called pimelic acid), a seven-carbon dicarboxylic acid. Structurally, dimethyl heptanedioate consists of a linear seven-carbon chain flanked by two methyl ester groups at each end.

The compound can be synthesized by the esterification of pimelic acid with methanol in the presence of an acid catalyst, such as sulfuric acid, under reflux conditions. This reaction produces the diester through a classical Fischer esterification mechanism. Dimethyl heptanedioate appears as a colorless to pale yellow liquid with a faint, pleasant odor. It is soluble in organic solvents like ethanol, ether, and chloroform, but exhibits limited solubility in water.

Dimethyl heptanedioate has been utilized primarily as an intermediate in organic synthesis and industrial chemistry. One of its important applications lies in the synthesis of polymers, particularly polyamides and polyesters. When hydrolyzed to pimelic acid or converted into pimeloyl chloride, the compound can be reacted with diamines or diols to produce various polycondensation products. These polymers may exhibit favorable thermal and mechanical properties useful in engineering plastics and fibers.

Additionally, dimethyl heptanedioate serves as a precursor for the preparation of cyclic compounds. Through intramolecular reactions such as Dieckmann condensation, this diester can form cyclic β-keto esters, which are valuable intermediates in the synthesis of heterocycles, pharmaceuticals, and agrochemicals. Such ring-forming reactions are commonly studied in synthetic organic chemistry as models for building complex molecular frameworks.

The ester is also employed in the preparation of plasticizers, lubricants, and specialty esters for industrial formulations. Due to its relatively low toxicity and ease of handling, it has been used in the development of functionalized materials and surface-modifying agents.

In laboratory research, dimethyl heptanedioate is sometimes used to study ester hydrolysis kinetics or to explore mechanisms of esterification and transesterification reactions. It is also relevant in the study of fatty acid metabolism, as pimelic acid is a known intermediate in the biosynthesis of biotin (vitamin B₇) in some microorganisms, although the dimethyl ester itself does not play a biological role.

In terms of safety, dimethyl heptanedioate is regarded as having low acute toxicity. Standard precautions are recommended during handling, including the use of gloves and eye protection. It should be stored in a cool, dry place, away from sources of ignition and incompatible materials such as strong oxidizing agents.

In conclusion, dimethyl heptanedioate is a valuable diester with utility in synthetic chemistry, materials science, and industrial applications. Its reactivity and versatility make it a useful intermediate for the preparation of polymers, cyclic compounds, and specialty chemicals. As a stable and accessible compound, it continues to serve as a practical building block in both academic and industrial research.

References

2017. Methylation of mono- and dicarboxylic acids with dimethyl carbonate catalyzed with binder-free zeolite NaY. Russian Journal of Organic Chemistry, 53(2).
DOI: 10.1134/s107042801702004x

2016. Kilogram Synthesis of Crebinostat. Synthesis, 48(3).
DOI: 10.1055/s-0035-1561917

2005. Dieckmann Condensation. Science of Synthesis.
URL: https://science-of-synthesis.thieme.com/app/text/?id=SD-026-01127