Nonanoyl Chloride: Properties, Handling & Lab Use Guide

Nonanoyl Chloride is a reactive C9 aliphatic acyl chloride widely employed in organic synthesis for the introduction of the nonanoyl group via acylation of amines, alcohols, and other nucleophiles.

Chemical Name

Nonanoyl Chloride (also known as Pelargonyl Chloride)

Molecular Formula

C9H17ClO

Molecular Weight

176.68 g/mol

CAS Number

764-85-2

Appearance

Colorless to pale yellow liquid with a pungent odor

Reactivity Class

Acyl chloride; highly reactive toward water and protic nucleophiles

Storage Condition

Store in a cool, dry, well-ventilated area; keep tightly sealed and away from moisture

Chemical Properties and Structure

Nonanoyl Chloride (CAS 764-85-2), systematically named nonan-1-oyl chloride and also referred to as pelargonyl chloride, is the acyl chloride derivative of nonanoic acid (pelargonic acid). Its molecular formula is C₉H₁₇ClO with a molecular weight of approximately 176.68 g/mol. The compound features a straight-chain nine-carbon acyl group attached to a highly electrophilic carbonyl carbon bearing a chloride leaving group, which accounts for its pronounced reactivity toward nucleophiles.

At ambient conditions, Nonanoyl Chloride presents as a colorless to pale yellow liquid with a sharp, irritating odor characteristic of low-molecular-weight acyl chlorides. It is miscible with common organic solvents such as dichloromethane, tetrahydrofuran, toluene, and diethyl ether, but reacts vigorously with water, alcohols, and amines, liberating hydrogen chloride gas in the process.

Synthetic Applications and Uses

As a versatile acylating agent, Nonanoyl Chloride is employed across a broad spectrum of synthetic transformations in medicinal chemistry, materials science, surfactant synthesis, and agrochemical research. Key applications include:

• Amide bond formation: Reaction with primary or secondary amines in the presence of a base (e.g., triethylamine or pyridine) affords the corresponding nonanamide derivatives. This is a standard route for preparing lipid-conjugated drug candidates and amphiphilic compounds.
• Ester synthesis: Acylation of alcohols or phenols with Nonanoyl Chloride under mild conditions yields nonanoate esters useful as lubricants, plasticizers, flavoring precursors, and lipid model compounds.
• Anhydride preparation: Controlled reaction with carboxylate salts provides mixed anhydrides that serve as activated acyl donors in further synthetic steps.
• Surface and polymer modification: The reagent is used to introduce nonanoyl pendant groups onto polymer backbones or surfaces, modifying hydrophobicity and surface energy in materials research.
• Biochemical probes: Nonanoyl derivatives of sugars, peptides, or lipids are synthesized for study of enzyme substrate specificity and membrane interactions.

Reactions are typically conducted under anhydrous conditions in inert solvents, and the hydrogen chloride generated is scavenged by an organic base or aqueous wash.

Safe Handling and Laboratory Precautions

Nonanoyl Chloride is a corrosive, moisture-sensitive reagent that demands rigorous safe-handling practices. The following precautions must be observed in all laboratory settings:

• Personal Protective Equipment (PPE): Wear chemical-resistant gloves (nitrile or neoprene), a laboratory coat, and safety goggles at all times. A face shield is recommended when handling larger volumes.
• Ventilation: All operations involving Nonanoyl Chloride should be performed inside a fume hood. Hydrolysis produces HCl vapors that are immediately dangerous to mucous membranes and the respiratory tract.
• Moisture exclusion: Use dry glassware, Schlenk techniques, or an inert-atmosphere glovebox for highly moisture-sensitive procedures. Store under nitrogen or argon if the container has been opened.
• Spill response: Contain spills immediately with dry sand or vermiculite. Do NOT use water, as this generates HCl and heat. Neutralize residual material with dilute sodium bicarbonate solution cautiously and dispose according to local regulations.
• First aid: In case of skin or eye contact, flush with copious water for at least 15 minutes and seek immediate medical attention. If inhaled, move to fresh air and obtain medical evaluation.
• Incompatibilities: Keep away from water, alcohols, strong bases, oxidizing agents, and reducing agents.

Storage, Stability, and Quality Considerations

Proper storage of Nonanoyl Chloride is essential to preserve reagent integrity and ensure reproducible results:

• Temperature: Store at controlled room temperature (15–25 °C) or as specified on the product label. Avoid exposure to heat sources or direct sunlight.
• Container: Keep in the original tightly sealed container. Use amber or opaque glass bottles to minimize photodegradation. Septum-sealed bottles with inert gas blankets are preferred for extended storage.
• Stability: Nonanoyl Chloride is susceptible to hydrolysis in the presence of atmospheric moisture to yield nonanoic acid and HCl. Gradual discoloration (yellowing) or turbidity upon standing may indicate partial hydrolysis and warrants quality assessment before use.
• Purity verification: For sensitive synthetic applications, purity should be confirmed by GC or titration of residual acid content prior to use. Aladdin Scientific provides specification data with each lot; consult the Certificate of Analysis (CoA) for exact purity and water content values.
• Waste disposal: Dispose of Nonanoyl Chloride and contaminated materials in accordance with local, national, and institutional chemical waste regulations. Quench waste material carefully with ice-cold water in a fume hood before disposal.

Frequently asked questions

What is the difference between Nonanoyl Chloride and Nonanoic Acid, and why use the acyl chloride?

Nonanoic acid is the carboxylic acid precursor, while Nonanoyl Chloride is its activated acyl chloride derivative bearing a far superior leaving group (Cl⁻ versus OH⁻). This makes Nonanoyl Chloride dramatically more reactive toward nucleophiles such as amines and alcohols, enabling efficient amide and ester formation under mild conditions without coupling reagents or prolonged heating.

How should I quench excess Nonanoyl Chloride after a reaction?

Carefully add the reaction mixture dropwise to ice-cold water or a dilute aqueous sodium bicarbonate solution in a fume hood. The acyl chloride hydrolyzes to nonanoic acid and HCl; the bicarbonate neutralizes the HCl produced. Allow gas evolution to cease before transferring to waste containers. Always perform this step slowly and with adequate cooling to control exothermicity.

Can Nonanoyl Chloride be used in aqueous reaction media?

Nonanoyl Chloride hydrolyzes rapidly in water, so purely aqueous conditions are generally incompatible. However, controlled two-phase (Schotten–Baumann) conditions—where the acyl chloride in an organic solvent is contacted with an aqueous amine solution containing a base—can be employed for interfacial acylation, provided the reaction is efficient enough to outcompete hydrolysis.

What solvents are recommended for reactions using Nonanoyl Chloride?

Anhydrous aprotic solvents are preferred: dichloromethane (DCM), tetrahydrofuran (THF), toluene, and diethyl ether are all suitable. These solvents must be thoroughly dried before use to prevent premature hydrolysis of the reagent. Protic solvents such as methanol or ethanol are not compatible as they react directly with the acyl chloride.

How do I assess whether my Nonanoyl Chloride has degraded during storage?

Visual inspection is a first indicator: significant yellowing, cloudiness, or formation of a precipitate suggests partial hydrolysis to nonanoic acid. For a quantitative check, GC analysis of purity or acid-base titration of free acid content can be performed. Always consult the lot-specific Certificate of Analysis from Aladdin Scientific and compare against your current sample's properties before critical synthetic use.

References

1. March, J. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley-Interscience: New York, 1992. (General acyl chloride reactivity and acylation reactions)
2. Clayden, J.; Greeves, N.; Warren, S. Organic Chemistry, 2nd ed.; Oxford University Press: Oxford, 2012. (Acyl chloride synthesis and nucleophilic acyl substitution mechanisms)
3. Aladdin Scientific. Product Certificate of Analysis for Nonanoyl Chloride, SKU N158958. (Lot-specific purity and physical data)

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