2-BUTYNE-1,4-DIOL

DESCRIPTION
2-Butyne-1,4-diol is an organic compound with the molecular formula C4H6O2. 
2-Butyne-1,4-diol is a diol, meaning it contains two hydroxyl groups (-OH), located at the 1st and 4th positions on the butyne (but-2-yne) chain. 
 
Cas Number: 110-65-6
 
SYNONYMS
2-Butyne-1,4-diol,110-65-6,But-2-yne-1,4-diol,Butynediol,1,4-Dihydroxy-2-butyne,1,4-BUTYNEDIOL,Bis(hydroxymethyl)acetylene,2-Butynediol,2-Butin-1,4-diol,1,4-Butinodiol,Butynediol-1,4,1,4-Butynediol (VAN),Butynediol-1,4 [French],1,4-Butinodiol [Spanish],1,Dimethoxyacetylene,DTXSID4021921,HSDB 2004,NSC 834,UNII-AXH202FPQM,EINECS 203-788-6,2-Butin-1,4-diol [Czechoslovakia],UN2716,BRN 1071237,CHEBI:16413,2-butyn-1,4-diol,AI3-61467,NSC-834,1,2-Dimethoxyacetylene,AXH202FPQM,DTXCID901921,1,4-BUTYNEDIOL [HSDB],EC 203-788-6,4-01-00-02687 (Beilstein Handbook Reference),UN 2716,Butynediol-1,4 (French),Agrisynth B3D,1,4-Butinodiol (Spanish),2-Butin-1,4-diol (Czechoslovakia),CAS-110-65-6,2-Butin-1,4-diol [Czech],But-2-in-1,4-diol,Butindiol,butynediols,2Butynediol,1,4Butinodiol,1,4Butynediol,Butynediol1,4,2Butyne1,4diol,But2yne1,4diol,2Butin1,4diol,MFCD00002915,1,4Dihydroxy2butyne,2-butyne-l,4-diol,but-2-yne-1,4diol,1,4Butynediol (VAN),1,4Dihydroxy-2-butyne,2-butyne-1,4-di-ol,2-Butyne-1, 4-diol,WLN: Q2UU2Q,1,4-BUTYNE GLYCOL,1,2-Dihydroxydimethylacetylene,NSC834,2-Butyne-1,4-diol, 99%,CHEMBL3187551,CHEBI:22970,Tox21_201284,Tox21_302875,STL185542,AKOS000118736,NCGC00249014-01,NCGC00256535-01,NCGC00258836-01,1,4-Butynediol [UN2716] [Poison],B0749,NS00009569,EN300-19323,Butynediol 1,4-Butynediol 2-Butyne-1,4-diol,C02497,E78871,Q209328,J-002458,F0001-0223,1,4-Butynediol; 1,4-Dihydroxy-2-butyne; 2-Butynediol; Bis(hydroxymethyl)acetylene; Butynediol; NSC 834
 
2-Butyne-1,4-diol (C4H6O2), commonly referred to as 1,4-dihydroxy-2-butyne, is a versatile organic compound that features both an alkyne group (-C≡C-) and two hydroxyl groups (-OH) at the 1 and 4 positions of the butyne chain. 
This molecule is of significant interest due to its potential as a precursor for a range of chemicals, particularly in the synthesis of high-performance polymers, resins, and specialty chemicals. 
In addition, 2-Butyne-1,4-diol has applications in pharmaceutical, agricultural, and materials sciences.
 
The compound’s structure, featuring an alkyne bond and hydroxyl groups, enables it to participate in a wide range of reactions, making it a valuable building block in organic synthesis. 
Its functional groups offer potential for use in the creation of bioactive molecules, functional materials, and complex polymers.
 
This article will explore the molecular structure, chemical properties, synthesis methods, applications, toxicity, environmental impact, and future research directions for 2-Butyne-1,4-diol.
 
CHEMICAL STRUCTURE AND PROPERTIES
Molecular Structure
2-Butyne-1,4-diol has a linear chain of four carbon atoms, with the hydroxyl (-OH) groups located at the terminal carbons (C1 and C4), and a triple bond (≡) between C2 and C3. The overall molecular structure is shown as:
 
HO-CH2-C≡C-CH2OH
 
The alkyne bond (C≡C) exhibits sp hybridization, which imparts a linear geometry to the central carbon atoms. 
The hydroxyl groups are attached to the terminal carbons, which are sp³ hybridized. 
The bond angles at the hydroxyl-terminated carbons are approximately 109.5°, typical for sp³ hybridization.
 
The compound can exist as two stereoisomers (cis and trans) due to the potential for cis-trans isomerism around the triple bond, although this is less commonly discussed in practical applications.
 
PHYSICAL PROPERTIES
Molecular weight: 86.1 g/mol
Boiling point: ~180°C (varies with impurities and pressure)
Melting point: 0-2°C (depending on purity)
Solubility: 2-Butyne-1,4-diol is highly soluble in water and polar solvents such as alcohols, acetone, and dimethyl sulfoxide (DMSO). Its solubility is attributed to the presence of hydroxyl groups which can form hydrogen bonds with solvent molecules.
Density: ~1.1 g/cm³
Vapor pressure: Relatively low due to the polar nature of the molecule.

Chemical Properties
Acid-Base Behavior: The hydroxyl groups in 2-Butyne-1,4-diol impart weakly acidic properties, though it is not strongly acidic like carboxylic acids. 

The molecule can participate in esterification reactions when treated with acids or anhydrides.
Reactivity: The alkyne group is highly reactive and can undergo various addition reactions, such as hydrogenation (to form alkenes or alkanes), halogenation, and electrophilic addition reactions.
Stability: 2-Butyne-1,4-diol is stable under standard conditions but may degrade under extreme conditions (e.g., high temperatures or acidic/basic environments). 

It is sensitive to oxidation, particularly under basic conditions, leading to the formation of diketones or other oxygenated derivatives.
Synthesis and Methods of Preparation
Traditional Synthesis Routes
One of the most common synthetic routes for 2-Butyne-1,4-diol involves the reaction of acetylene (C2H2) with formaldehyde (CH2O) under basic conditions. 
The reaction proceeds via a nucleophilic addition mechanism, where the formaldehyde undergoes condensation with acetylene, followed by hydrolysis to produce the desired diol.
 
Reaction mechanism:
 
Acetylene is reacted with formaldehyde in the presence of a base (e.g., sodium hydroxide) to form an intermediate.
The intermediate is subsequently hydrolyzed, resulting in the formation of 2-Butyne-1,4-diol.
This route, however, can suffer from low yields and issues with selectivity.
 
Innovative and Alternative Methods
In the pursuit of greener and more efficient chemical synthesis, researchers have explored alternative methods for synthesizing 2-Butyne-1,4-diol. 
One such approach involves enzyme-catalyzed reactions, which can improve selectivity and reduce by-products. 
Enzyme-based processes offer the advantage of milder reaction conditions, lower energy consumption, and more sustainable use of resources.
 
Additionally, continuous flow synthesis has emerged as a promising approach for large-scale production. 
Continuous flow systems allow for better control over reaction conditions, reduce waste generation, and offer more consistent product quality.
 
Challenges in Synthesis
The main challenge in the synthesis of 2-Butyne-1,4-diol lies in optimizing reaction conditions to achieve high yields while minimizing side products.
Other challenges include controlling the stereochemistry of the product and scaling up reactions for industrial use. 
The synthesis often requires careful temperature and pH control to avoid undesirable decomposition or side reactions.
 
Mechanisms of Reactivity and Reactions
Reactions Involving the Alkyne Group
The alkyne group (C≡C) in 2-Butyne-1,4-diol is highly reactive and can undergo numerous addition reactions:
 
Electrophilic Addition: The alkyne bond can be attacked by electrophiles, such as halogens (Cl₂, Br₂), to form vinyl halides. 
This reactivity is a key feature in the functionalization of 2-Butyne-1,4-diol for various chemical processes.
Hydrogenation: The alkyne bond can be hydrogenated in the presence of a catalyst (e.g., palladium on carbon) to form a cis or trans alkene, depending on the conditions.
Cyclization: Under certain conditions, the alkyne can react with nucleophiles to form cyclic compounds, which can be useful in the synthesis of cyclic diols or related structures.
Reactions of the Hydroxyl Group
The hydroxyl groups in 2-Butyne-1,4-diol are reactive in various ways:
 
Esterification: 2-Butyne-1,4-diol can react with acids or acid chlorides to form esters. 
The hydroxyl groups also facilitate reactions with anhydrides or other electrophilic species.
Oxidation: The hydroxyl groups can undergo oxidation, converting them into ketones, aldehydes, or even carboxylic acids under harsh conditions. 
The alkyne group may also undergo oxidation, leading to the formation of diketone products.
Polymerization: The hydroxyl groups can participate in polymerization reactions, especially when reacting with isocyanates to form polyurethanes or with epoxides to form polyesters.
Polymerization and Copolymerization
2-Butyne-1,4-diol is useful as a monomer in the synthesis of high-performance polymers. 
It can be polymerized alone or copolymerized with other monomers to create materials with specialized properties:
 
Polyurethane Formation: The hydroxyl groups react with isocyanates to form polyurethanes, which have excellent mechanical properties and resistance to heat and chemicals.
Polyester Formation: When combined with diacid chlorides or epoxides, 2-Butyne-1,4-diol can form polyesters with various properties depending on the monomer used.
Applications
Industrial Applications
2-Butyne-1,4-diol is primarily used in the synthesis of industrial chemicals:
 
Polymer Synthesis: It serves as a building block for the production of polyurethanes, polyesters, and epoxy resins. 
These materials are used in coatings, adhesives, and automotive parts.
Resins and Plastics: It is used in the production of thermoplastic resins that offer high strength and durability.
Lubricants and Additives: The hydroxyl groups make it a useful intermediate in the preparation of lubricants and additives for industrial machinery.
Pharmaceutical and Agricultural Chemistry
2-Butyne-1,4-diol is being explored as a precursor in the synthesis of pharmaceutical agents, including bioactive molecules such as anti-cancer and anti-inflammatory drugs. 
It is also used in the development of agrochemicals, including pesticides and herbicides.
 
Materials Science and Engineering
In materials science, 2-Butyne-1,4-diol is used to produce advanced functional materials. 
Its incorporation into polymer matrices allows for the creation of materials with enhanced properties such as improved thermal stability, chemical resistance, and mechanical strength. 
These materials find applications in electronics, aerospace, and construction.
 
Recent Research and Developments
Recent studies focus on improving the synthesis, scalability, and applications of 2-Butyne-1,4-diol:
 
New Catalysts: Researchers have been developing more efficient catalysts for the synthesis of 2-Butyne-1,4-diol, aiming to reduce reaction time and increase yield.
Biocatalysis: The use of enzymes to catalyze the formation of 2-Butyne-1,4-diol is gaining interest due to its environmentally friendly nature.
Nanomaterials: Ongoing research explores the use of 2-Butyne-1,4-diol in creating nanomaterials with specific properties for applications in electronics and renewable energy.
Conclusion
2-Butyne-1,4-diol is a promising compound with a diverse range of applications in industrial chemistry, materials science, and pharmaceuticals. 
Ongoing research aims to improve the sustainability of its production and explore new applications in emerging fields. 
As environmental concerns and the demand for high-performance materials grow, 2-Butyne-1,4-diol may play a key role in meeting these needs.

SAFETY INFORMATION ABOUT 2-BUTYNE-1,4-DIOL
First aid measures:
Description of first aid measures:
General advice:
Consult a physician. 
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
 
If inhaled:
If breathed in, move person into fresh air. 
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately. 
Wash off with soap and plenty of water.
Consult a physician.
 
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
 
If swallowed:
Do NOT induce vomiting. 
Never give anything by mouth to an unconscious person. 
Rinse mouth with water. 
Consult a physician.
 
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
 
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment. 
 
Avoid breathing vapours, mist or gas. 
Evacuate personnel to safe areas.
 
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste. 
Keep in suitable, closed containers for disposal.
 
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
 
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place. 
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
 
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
 
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles. 
Faceshield (8-inch minimum). 
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
 
Skin protection:
Handle with gloves. 
Gloves must be inspected prior to use. 
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product. 
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. 
Wash and dry hands.
 
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
 
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. 
 
If the respirator is the sole means of protection, use a full-face supplied air respirator. 
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so. 
Do not let product enter drains.
Discharge into the environment must be avoided.
 
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions. 
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
 
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company. 
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product