Propargyl Alcohol

Propargyl Alcohol (CAS: 107-19-7) Supplier in Europe

Propargyl alcohol, known by the chemical formula C3H4O, is an organic compound that plays a critical role in various chemical reactions and industrial applications. As the simplest stable alcohol comprising an alkyne functional group,

Chemical Structure

Propargyl alcohol, with the molecular formula C₃H₄O, is characterized by the presence of an alkyne functional group within its structure. This organic compound is also known by its IUPAC name, 2-propyn-1-ol.

At its core, the molecule consists of a three-carbon chain. The alkyne functional group is represented by a triple bond between the first and second carbons. The chemical structure can be further detailed as follows:

• Carbon 1 (C1): Attached to a hydroxyl group (-OH), classifying the compound as an alcohol.
• Carbon 2 (C2): Involved in a triple bond with C1 (sp hybridization).
• Carbon 3 (C3): A terminal methyl group, making it the simplest stable alcohol containing an alkyne.

Molecular Weight: 56.063 Da

The structural breakdown of propargyl alcohol is:

• Hydroxyl group (-OH): At the terminal end (C1).
• Alkyne group (C≡C): Between C1 and C2, contributes to the reactivity of the compound.

The alkyne group lends the molecule unique reactivity that makes it suitable for various synthetic applications. Propargyl alcohol is often exploited in organic synthesis due to the activity of the alkyne group, allowing it to participate in a range of chemical reactions.

In summary, propargyl alcohol presents a distinctive structure, combining the features of an alcohol with an alkyne, a duality that underpins its utility in various chemical processes.

Production Methods

The industrial production of propargyl alcohol hinges on two primary methods—each offering distinct pathways for the synthesis of this important chemical intermediate.

Allene Method

Industrial synthesis of propargyl alcohol often occurs as a by-product in the Allene Method, specifically during the production of but-2-yne-1,4-diol. The key process involves the copper-catalyzed addition of formaldehyde to acetylene. Alternatively, it can be prepared via the dehydrochlorination of 3-chloro-2-propen-1-ol using sodium hydroxide (NaOH) as a base, which effectively eliminates hydrogen chloride (HCl) to form the propargyl alcohol.

Propargylation

Propargylation refers to the process of adding a propargyl group to a molecular scaffold. This can be achieved through various reactions, including the coupling of aldehydes or ketones with alkynyl propiolates. This method does not require a base and tolerates a variety of functional groups. The reaction setup generally includes reagents that are straightforward to handle, enabling its broad use in synthetic applications.

Key Points:

• Reactants: aldehydes or ketones, alkynyl propiolates
• Catalyst: usually not required
• Functional Group Tolerance: high
• Base: not required

Physical Properties

Propargyl alcohol, with the chemical formula C3H4O, presents as a colorless liquid at room temperature. Its molecular weight is 56.07 g/mol, and the substance possesses a distinctive geranium-like odor.

The boiling point of propargyl alcohol is documented at 236.5°F (113.6°C), making it relatively volatile. The flash point—the temperature at which the substance gives off enough vapor to ignite in the air—is recorded at 97°F (36.1°C).

Here are key physical properties of propargyl alcohol:

• Appearance: Clear, colorless liquid
• Odor: Geranium-like
• Boiling Point: 236.5°F (113.6°C)
• Flash Point: 97°F (36.1°C)

Propargyl alcohol is known for its miscibility with water and many polar organic solvents due to its functional alkyne group. The liquid’s vapor density is greater than air, which implies that its vapors could accumulate at the ground level, potentially creating an inhalation hazard.

Safety considerations are paramount when handling propargyl alcohol due to its flammability. It should be stored and used in well-ventilated areas away from sources of ignition.

Regarding its industrial applications, propargyl alcohol serves as a precursor to several chemicals and also functions effectively as a corrosion inhibitor and soil fumigant.

Property	Value
Molecular Weight	56.07 g/mol
Boiling Point	236.5°F (113.6°C)
Flash Point	97°F (36.1°C)
Solubility	Miscible with water and polar organic solvents
Odor	Geranium-like

Chemical Properties

Propargyl alcohol, with the chemical formula C₃H₄O, is a colorless liquid that possesses a distinctive, geranium-like odor. It is known for its ability to mix well with water and many polar organic solvents due to its polar nature. This alcohol has a flash point of 97 °F, indicating that it can vaporize into a flammable mixture at relatively low temperatures.

The substance is identified by its CAS Registry Number: 107-19-7. Propargyl alcohol has a molecular weight of 56.06 g/mol, and its structure includes a terminal alkyne group, which is a carbon-carbon triple bond, making it a reactive molecule in various chemical reactions.

In terms of reactivity, Propargyl alcohol is notable for its tendency to polymerize upon heating or when treated with base. This characteristic is harnessed in industrial applications where it acts as a precursor to more complex polymers. The alcohol is sensitive to air and light, which can initiate polymerization as well.

Here’s a summary of key properties:

• Molecular Formula: C₃H₄O
• Average Mass: 56.06 Da
• Flash Point: 97 °F
• Solubility: Miscible with water and polar organic solvents
• Reactivity: Polymerizes with heat or base treatment

Safety-wise, Propargyl alcohol’s vapors are heavier than air and can form flammable mixtures, prompting caution during handling to prevent ignition.

Applications

Propargyl alcohol is a versatile chemical with a range of applications in various industries. Its unique reactivity is utilized for creating complex molecules, enhancing polymers, and various industrial processes.

Pharmaceutical Synthesis

In pharmaceutical synthesis, propargyl alcohol serves as an intermediate in the formation of active pharmaceutical ingredients (APIs). It is commonly used to introduce alkyne functional groups into larger molecules, facilitating the creation of medications that require a triple-bond structure for efficacy.

Polymer Production

Polymer production benefits greatly from propargyl alcohol as a monomer. When exposed to heat or base, it polymerizes, forming polymers with desirable properties. It acts as a corrosion inhibitor and stabilizes solvents, making it especially valuable in producing coatings and adhesives.

Industrial Synthesis

Propargyl alcohol is instrumental in industrial synthesis. It functions as an electroplating brightener additive and is frequently used for synthesizing metal complex solutions. These applications harness its reactivity to improve the brightness and adherence of plating on metal surfaces.

Safety and Handling

In handling propargyl alcohol, one must adhere strictly to robust safety and storage protocols due to its highly flammable nature and toxicity.

Storage Requirements

• Temperature: Store propargyl alcohol in a cool, well-ventilated area away from heat sources.
• Containers: Keep in suitable, tightly sealed containers and ensure they are clearly labeled.
• Segregation: Separate from oxidizing agents, acids, and alkalies to prevent hazardous reactions.

Safety Precautions

• Personal Protective Equipment (PPE): Wear appropriate PPE including gloves, goggles, and respirator for protection against spills, splashes, or vapors.
• Ventilation: Ensure adequate ventilation in the working area to mitigate inhalation risks.
• Spill Management: In case of a spill, utilize inert absorbent material while avoiding ignition sources.
• Disposal: Dispose of propargyl alcohol in accordance with local, state, and federal regulations.

Regulatory Status

Propargyl alcohol, with the CAS Number 107-19-7, is subject to regulation by various agencies based on its application and potential health impacts. OSHA has included propargyl alcohol in its Occupational Chemical Database, providing guidelines for handling and exposure in the workplace. Exposure limits and safety precautions are detailed to ensure worker safety.

The U.S. Environmental Protection Agency (EPA) has propargyl alcohol listed within its Substance Registry Services. The substance has a molecular weight of 56.06 g/mol and is recognized as a chemical substance used in various industrial applications. However, an assessment for inhalation exposure (RfC) or cancer has not been completed under the EPA’s Integrated Risk Information System (IRIS) as of the last update.

NOAA’s CAMEO Chemicals database describes propargyl alcohol as a highly flammable liquid, highlighting its physical properties and associated hazards. It also outlines emergency guidelines like the NFPA 704 standard, which denotes flammability and other risks tied to the substance.

Agency	Regulation Aspect	Documentation
OSHA	Workplace exposure guidelines	Occupational Chemical Database
EPA	Chemical tracking and safety	Substance Registry Services
NOAA	Emergency response and hazards	CAMEO Chemicals

Regulations are crucial to ensure the safe handling, transportation, and use of propargyl alcohol in different settings. Entities dealing with the substance must comply strictly with these regulations to mitigate health risks and potential environmental impact.

Analytical Methods

Analytical techniques for propargyl alcohol focus on accurately identifying and quantifying the substance, utilizing its specific chemical properties.

Spectroscopy

In the spectroscopic analysis of propargyl alcohol, several techniques can be employed. Infrared spectroscopy (IR) is widely used to identify the characteristic C≡C (acetylenic) and O-H bonds. It provides a fingerprint specific to propargyl alcohol. Nuclear Magnetic Resonance (NMR) spectroscopy is another valuable tool, where ^1H NMR and ^13C NMR can elucidate the structure of the alcohol, specifically assessing the environment of the hydroxyl group and the acetylenic hydrogens.

Chromatography

Chromatographic methods are pivotal in separating propargyl alcohol from other components in a mixture. Gas Chromatography (GC) is most commonly preferred due to its efficiency in volatile organic compounds analysis. GC coupled with a Flame Ionization Detector (FID) can quantify propargyl alcohol by measuring the ionization of carbon atoms. Moreover, High-Performance Liquid Chromatography (HPLC) can also be utilized, particularly when dealing with less volatile substances or complex mixtures requiring a more nuanced separation.

Environmental Impact

Propargyl alcohol, a chemical with diverse applications, exhibits characteristics that necessitate proper handling due to its environmental implications.

Toxicity and Contamination Risks:

• Soil Fumigant: Propargyl alcohol is employed as a soil fumigant, and its residues could potentially affect soil ecology.
• Aquatic Toxicity: If released into waterways, it could be toxic to aquatic organisms, although detailed data on this aspect is currently limited.

Regulatory Aspects:

• EPA Oversight: The United States Environmental Protection Agency (EPA) monitors and regulates chemicals such as propargyl alcohol to ensure environmental safety.
• Production and Usage Figures: Its annual production in the U.S. has been estimated to be between 0.5 to 2.8 million pounds, indicating its significant presence in industrial use.

Chemical Stability and Reactivity:

• Propargyl alcohol is moderately volatile. It can degrade in the environment, however, the rate and products of degradation are factors that require more research.

Hazardous Nature:

• Flammability: Being flammable, it poses fire and explosion risks which can result in environmental pollution.
• Irritant Properties: It’s known to be an irritant that can cause adverse effects on exposed fauna or flora.

Given the potential environmental impact of propargyl alcohol, it is clear that careful management of its use, disposal, and accidental release is critical in minimizing its ecological footprint.

Frequently Asked Questions

This section addresses common inquiries about propargyl alcohol, encompassing its applications, properties, safe handling practices, purification methods, NMR interpretation, and chemical reaction mechanisms.

What are the typical applications and uses of propargyl alcohol in industry?

Propargyl alcohol is utilized as a chemical intermediate, solvent stabilizer, soil fumigant, and corrosion inhibitor. Its annual production in the United States suggests its significance across various industrial activities.

What are the physical properties, such as density and boiling point, of propargyl alcohol?

Propargyl alcohol is a colorless, viscous liquid with a geranium-like odor. It is miscible with water and most polar solvents. The exact values for density and boiling point are determined through scientific measurements and are essential for its handling and application in industry.

What precautions should be taken to handle propargyl alcohol safely, considering its toxicity?

Handling propargyl alcohol requires adherence to safety guidelines due to its toxicity. Protective gear, proper ventilation, and adherence to OSHA’s workplace exposure limits are imperative to minimize health risks.

How can propargyl alcohol be purified through distillation?

Distillation purifies propargyl alcohol by heating it to its boiling point, allowing vapors to condense into a purified liquid form. This process hinges on the precise boiling point of propargyl alcohol.

What is the interpretation of propargyl alcohol’s nuclear magnetic resonance (NMR) spectra?

Interpreting the NMR spectra of propargyl alcohol involves analyzing the chemical shifts and splitting patterns to identify the molecular structure and environment of hydrogen atoms within the molecule.

Can you explain the chemical mechanism underlying reactions involving propargyl alcohol?

The reactivity of propargyl alcohol in chemical reactions is attributed to the acetylenic bond present in its structure. This bond makes it conducive to polymerization and other chemical transformations, a property exploited in various synthetic processes.