Trans-2,3-Dibromo-2-butene-1,4-diol purity 99% Dideu White powder CAS number 3234-02-4

1. Basic Information

• English Name: 2,3 - Dibromo - 1,4 - butenediol
• Abbreviation: DBD
• Molecular Formula: C₄H₆Br₂O₂
• Molecular Weight: 275.9

2. Physical and Chemical Properties

• Appearance: Usually a white to pale - yellow crystalline powder. This appearance makes it easy to observe and identify during storage and use.
• Melting Point: 110 - 114°C. The melting point is an important physical parameter of this compound, which has significant reference value in aspects such as compound purification, identification, and control of reaction conditions during synthesis.
• Solubility: Slightly soluble in water and soluble in organic solvents such as ethanol, acetone, and chloroform. Its solubility characteristics determine how to select appropriate solvents to promote reactions or achieve specific functions of the compound in different chemical reactions and application scenarios.

3. Uses

• Pharmaceutical Intermediate: In pharmaceutical synthesis, DBD is a key intermediate for the synthesis of various drugs. Functional groups such as carbon - carbon double bonds, hydroxyl groups, and bromine atoms in its molecular structure endow it with rich chemical reactivity. For example, through nucleophilic substitution reactions, the hydroxyl group or bromine atom can be replaced by other functional groups with specific pharmacological activities, thus constructing drug molecular structures with different therapeutic effects.
• Pesticide Intermediate: As an important intermediate in pesticide synthesis, pesticides synthesized with DBD have a variety of excellent properties. For example, some pesticides with DBD - derived structures have unique mechanisms of action on pests. The bromine atoms in these pesticides can enhance the binding ability of the pesticide molecules to specific targets in pests, thereby interfering with the normal physiological metabolism of pests, such as signal transduction in the nervous system and energy metabolism, ultimately leading to the death of pests and improving the control effect of pesticides.
• Organic Synthesis: In the field of organic synthesis, DBD, with its unique molecular structure and diverse functional - group reactivity, serves as an important starting material for constructing complex organic molecular structures. By rationally designing reaction routes, organic chemists can carry out addition reactions using the carbon - carbon double bonds in DBD to introduce different functional groups or molecular fragments. At the same time, the hydroxyl and bromine atoms can also participate in reactions such as nucleophilic substitution and elimination respectively, realizing the step - by - step construction and functionalization of molecules. For example, in the synthesis of organic functional materials with specific optical, electrical, or biological activities, DBD can be used as a key structural unit. Through a series of organic synthesis reactions, it is connected and assembled with other organic molecules or groups with specific functions, thus constructing a complex organic molecular system with the required properties and functions.

4. Synthesis Methods

• Using Butadiene as Raw Material
  • Step 1: Addition Reaction to Generate 1,2,3,4 - Tetrabromobutane: In an appropriate solvent (such as dichloromethane), butadiene reacts with bromine through an addition reaction. Dichloromethane, as the reaction solvent, can provide a homogeneous environment for the reaction, facilitating sufficient contact and collision between reactant molecules, thus promoting the smooth progress of the addition reaction. The reaction equation is: CH₂=CH - CH=CH₂ + 2Br₂ → CH₂Br - CHBr - CHBr - CH₂Br
  • Step 2: Elimination Reaction to Generate 2,3 - Dibromo - 1,3 - Butadiene: Subsequently, under alkaline conditions (such as an ethanol solution of potassium hydroxide), 1,2,3,4 - tetrabromobutane undergoes an elimination reaction. The ethanol solution not only serves as a reaction solvent but also participates in the proton - transfer step during the reaction. The hydroxide ions ionized from potassium hydroxide in the ethanol solution act as strong bases, capable of abstracting the β - hydrogen atom from the 1,2,3,4 - tetrabromobutane molecule. At the same time, the bromide ion leaves the molecule as a leaving group, thus removing two molecules of hydrogen bromide and generating 2,3 - dibromo - 1,3 - butadiene. The reaction equation is: CH₂Br - CHBr - CHBr - CH₂Br + 2KOH → CH₂=CBr - CBr=CH₂ + 2KBr + 2H₂O
  • Step 3: Addition Reaction to Generate 2,3 - Dibromo - 1,4 - Butenediol: Finally, in the presence of an acidic catalyst (such as sulfuric acid), 2,3 - dibromo - 1,3 - butadiene reacts with water through an addition reaction. Sulfuric acid, as an acidic catalyst, can enhance the electrophilicity of the carbon - carbon double bond in 2,3 - dibromo - 1,3 - butadiene through protonation, thus promoting the nucleophilic addition reaction of water molecules to the carbon - carbon double bond. During the reaction, the oxygen atom in the water molecule acts as a nucleophile to attack one of the carbon atoms in the carbon - carbon double bond, while the other carbon atom gains a proton, forming a carbocation intermediate. Subsequently, the intermediate undergoes intramolecular rearrangement, and finally 2,3 - dibromo - 1,4 - butenediol is formed. The reaction equation is: CH₂=CBr - CBr=CH₂ + H₂O → HOCH₂ - CHBr - CHBr - CH₂OH
• Using 1,4 - Butynediol as Raw Material
  • Step 1: Partial Addition Reaction to Generate 1,4 - Butenediol: In the presence of a catalyst (such as palladium - on - carbon), 1,4 - butynediol reacts with hydrogen through a partial addition reaction. The palladium atoms in the palladium - on - carbon catalyst have a special electronic structure, which can adsorb hydrogen molecules and dissociate them into active hydrogen atoms. At the same time, the palladium atoms can also adsorb 1,4 - butynediol molecules, activating their carbon - carbon triple bond to a certain extent. Under these circumstances, the active hydrogen atoms react with the activated carbon - carbon triple bond through an addition reaction, adding only one molecule of hydrogen to the carbon - carbon triple bond, thus generating 1,4 - butenediol. The reaction equation is: HOCH₂ - C≡C - CH₂OH + H₂ → HOCH₂ - CH=CH - CH₂OH
  • Step 2: Addition Reaction to Generate 2,3 - Dibromo - 1,4 - Butenediol: Then, dissolve 1,4 - butenediol in an appropriate solvent (such as carbon tetrachloride), and slowly add a carbon tetrachloride solution of bromine. The addition reaction is carried out at low temperature. Carbon tetrachloride, as the reaction solvent, has good solubility and chemical stability, providing a relatively mild and homogeneous environment for the reaction. At low temperature, adding the bromine - carbon tetrachloride solution slowly enables the bromine molecules to fully contact and react with the carbon - carbon double bond in 1,4 - butenediol. Since the reaction is carried out at low temperature and the bromine is added slowly, side reactions can be effectively avoided, and 2,3 - dibromo - 1,4 - butenediol can be obtained with high selectivity. The reaction equation is: HOCH₂ - CH=CH - CH₂OH + Br₂ → HOCH₂ - CHBr - CHBr - CH₂OH

5. Safety - related Information

• Health Hazards: DBD is irritating to the eyes, skin, and respiratory tract. If it comes into contact with the eyes accidentally, it may cause symptoms such as eye redness, pain, and tearing. In severe cases, it may even damage eyesight. After contact with the skin, it may lead to skin redness, itching, and rash. Prolonged or repeated contact may also trigger skin allergic reactions. Inhaling DBD dust or its volatiles may irritate the respiratory tract, causing symptoms such as coughing, wheezing, and difficulty breathing. The harm may be more serious for people with respiratory diseases (such as asthma, chronic obstructive pulmonary disease, etc.).
• Protective Measures: When handling DBD, strict protective measures should be taken. Operators should wear appropriate protective glasses, such as chemical safety goggles, to prevent DBD from coming into contact with the eyes. Wearing protective clothing, such as rubber acid - and - alkali - resistant clothing, can effectively protect the skin from the irritation and damage of DBD. At the same time, a protective mask must be worn. For chemicals with irritation like DBD, it is recommended to wear a self - contained breathing apparatus with a full - face mask to prevent inhaling DBD dust or volatiles. In addition, eyewashers and shower facilities should be equipped at the operation site so that in case of accidental contact with DBD, timely flushing and treatment can be carried out to reduce harm to the body.
• Environmental Impact: DBD and its decomposition products may have a certain impact on the environment. Due to its certain chemical activity, a series of chemical reactions may occur in the environment, thus affecting the balance of the ecosystem. For example, when DBD enters water bodies, it may be toxic to aquatic organisms, affecting their growth, reproduction, and survival. In addition, DBD may also be transferred and enriched through the food chain, posing potential hazards to organisms at higher trophic levels. At the same time, the residue of DBD in the soil may also have an adverse impact on the soil microbial community and soil ecosystem functions, thus affecting the growth and development of plants. Therefore, during the production, use, and treatment of DBD, its potential impact on the environment must be fully considered, and corresponding environmental protection measures should be taken to reduce its pollution and damage to the environment.