Dimethyl Pimelate: Properties, Synthesis & Lab Uses

Dimethyl Pimelate is a bifunctional diester compound serving as a versatile building block in organic synthesis, polymer chemistry, and biochemical cross-linking applications.

Chemical Name

Dimethyl Pimelate (Dimethyl heptanedioate)

CAS Number

1732-08-7

Molecular Formula

C9H16O4

Molecular Weight

188.22 g/mol

Appearance

Colorless to pale yellow liquid

Primary Use

Monomer in polyester/polyamide synthesis; organic synthesis intermediate

Available SKU

D155392 (Aladdin Scientific)

Chemical Identity and Physical Properties

Dimethyl Pimelate, also known as dimethyl heptanedioate, is the dimethyl ester of pimelic acid (heptanedioic acid). It carries the CAS registry number 1732-08-7 and has the molecular formula C₉H₁₆O₄ with a molecular weight of 188.22 g/mol. The compound features two terminal methyl ester groups connected by a five-carbon methylene chain, conferring conformational flexibility that makes it reactive toward a range of nucleophilic and electrophilic transformations.

Under ambient conditions, Dimethyl Pimelate is typically encountered as a colorless to pale yellow liquid. It is miscible with common organic solvents such as ethanol, diethyl ether, acetone, and dichloromethane, while exhibiting limited solubility in water. These solubility characteristics facilitate its use in a wide variety of reaction media. The ester functional groups are susceptible to hydrolysis under acidic or basic aqueous conditions, regenerating pimelic acid and methanol, a property that must be considered during workup procedures.

Synthesis and Manufacturing Overview

Dimethyl Pimelate is most commonly prepared by the Fischer esterification of pimelic acid with methanol in the presence of an acid catalyst, such as sulfuric acid or p-toluenesulfonic acid, under reflux conditions. The reaction proceeds via protonation of the carboxylic acid carbonyl, nucleophilic addition of methanol, and elimination of water to yield the diester product. Because pimelic acid is symmetric, only a single diester product is obtained, simplifying purification.

Alternative synthetic routes include transesterification of higher pimelic acid esters with methanol, as well as ring-opening of caprolactone derivatives under controlled conditions. Industrial-scale production typically employs continuous esterification processes with heterogeneous acid catalysts to achieve high yields and purity. Research-grade material, such as that supplied by Aladdin Scientific (SKU D155392), undergoes rigorous purity analysis to ensure consistent performance in sensitive applications.

Laboratory Applications and Research Uses

Polymer and Material Science: Dimethyl Pimelate is widely employed as a monomer in the preparation of polyesters and polyamides via melt or solution polycondensation. When reacted with diols (e.g., 1,4-butanediol or ethylene glycol) under transesterification conditions, it generates aliphatic polyesters with tunable thermal and mechanical properties. These polymers are of interest in biodegradable materials research and biomedical applications. Its seven-carbon backbone imparts greater flexibility compared to shorter-chain diacid esters such as dimethyl glutarate or dimethyl adipate.

Organic Synthesis Intermediate: As a bifunctional electrophile, Dimethyl Pimelate participates in Claisen condensation reactions to form cyclic or linear beta-keto ester products. It is also used in the synthesis of macrocyclic compounds, natural product analogs, and pharmaceutical intermediates where precise chain length is required. The compound can undergo partial reduction to monoalcohol-monoester intermediates using controlled amounts of hydride-reducing agents.

Biochemical and Cross-linking Studies: Pimelic acid-derived spacers have been explored in the design of bifunctional cross-linkers for protein labeling and affinity chromatography ligand attachment. The methyl ester form facilitates controlled activation and coupling under mild conditions.

Handling, Storage, and Safety Guidelines

Personal Protective Equipment (PPE): When handling Dimethyl Pimelate, researchers should wear appropriate chemical-resistant gloves (nitrile recommended), safety glasses or goggles, and a laboratory coat. Work in a well-ventilated area or under a fume hood to minimize inhalation of vapors, particularly when heating the compound.

Storage Conditions: Store Dimethyl Pimelate in a tightly sealed container away from heat sources, open flames, and incompatible materials such as strong oxidizers and strong bases. Recommended storage temperature is at room temperature (15–25 °C) in a cool, dry location. Protect from moisture to prevent hydrolysis over extended storage periods.

Disposal: Dispose of Dimethyl Pimelate and contaminated materials in accordance with local, regional, and national regulations governing organic solvent waste. Do not pour into drains or water systems. Consult the product Safety Data Sheet (SDS) for complete hazard information before use. Aladdin Scientific provides an SDS for SKU D155392 upon request and through the product listing page.

Frequently asked questions

What is Dimethyl Pimelate used for in polymer synthesis?

Dimethyl Pimelate serves as a difunctional monomer for the preparation of aliphatic polyesters and polyamides via polycondensation reactions with diols or diamines, respectively. Its seven-carbon chain contributes flexibility and influences the thermal properties of the resulting polymers. It is also studied in the context of biodegradable polymer development.

How should Dimethyl Pimelate be stored to maintain its stability?

Dimethyl Pimelate should be stored in a tightly sealed container at room temperature (15–25 °C) in a cool, dry location, away from strong bases, oxidizers, moisture, and direct heat sources. Moisture exposure can promote hydrolysis of the ester groups over time, reducing reagent purity and performance.

Is Dimethyl Pimelate the same as pimelic acid?

No. Pimelic acid (heptanedioic acid) is the parent dicarboxylic acid, while Dimethyl Pimelate is its dimethyl diester derivative in which both carboxylic acid groups have been converted to methyl esters. They share the same seven-carbon backbone but differ significantly in physical properties and chemical reactivity; the ester form is generally a liquid and more amenable to transesterification and condensation reactions under milder conditions.

What solvents are compatible with Dimethyl Pimelate?

Dimethyl Pimelate is miscible with most common organic solvents including ethanol, methanol, acetone, diethyl ether, tetrahydrofuran (THF), and dichloromethane. It has limited solubility in water. Avoid strongly alkaline or strongly acidic aqueous media for extended contact, as these conditions promote hydrolysis of the ester linkages.

Where can I purchase research-grade Dimethyl Pimelate?

Research-grade Dimethyl Pimelate is available from Aladdin Scientific under SKU D155392. The product undergoes quality control testing to verify purity suitable for laboratory and research applications. Contact Aladdin Scientific for current pricing, available pack sizes, and certificate of analysis documentation.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992.
2. Odian, G. Principles of Polymerization, 4th ed.; Wiley-Interscience: Hoboken, NJ, 2004.
3. National Center for Biotechnology Information. PubChem Compound Summary for CAS 1732-08-7, Dimethyl pimelate. PubChem. Accessed 2024.

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