5-Chlorovaleryl chloride(link:https://www.bloomtechz.com/synthetic-chemical/organic-intermediates/5-chlorovaleryl-chloride-cas-1575-61-7.html) is an organic compound that contains carboxylic acid and halogen groups in its structure. This compound can be synthesized by various methods. Some of these methods are described below:
1. Chlorination of pentachloroacetic acid:
Pentachloroacetic acid is prepared by adding excess hydrochloric acid at room temperature. The following steps can be taken:
(1.) Prepare reagents:
Pentachloroacetic acid, phosphorus oxychloride, deionized water or desiccant
(2.) Prepare the reaction mixture:
In a dry reaction bottle, add pentachloroacetic acid and phosphorus oxychloride to deionized water or a desiccant, while stirring and cooling the reaction material to below 0°C.
(3.) Add 5-Chlorovaleryl chloride:
Slowly add 5-Chlorovaleryl chloride to the reaction mixture while keeping the temperature below 0°C. After the addition is complete, the reaction mixture turns milky white.
(4.) For further reaction:
Keep the reaction mixture below 0°C and continue to stir for 30 minutes, then add a certain amount of deionized water or desiccant to make the reaction mixture turn pale yellow.
(5.) Isolated product:
The reaction mixture was subjected to vacuum distillation to separate the product, at which time the 5-Chlorovaleryl chloride product was initially obtained.
(6.) Purified product:
The 5-Chlorovaleryl chloride product obtained above can be purified by recrystallization in dimethyl carbonate below 0°C, and then pure 5-Chlorovaleryl chloride can be obtained by filtrate and drying.
It should be noted that in the steps of the chlorination method, the reactants and the reaction mixture need to be kept under dry and low temperature conditions to ensure the success of the reaction and the purification of the product. In addition, the phosphorus oxychloride during the reaction needs to be handled with extreme care to avoid dangerous chemical reactions.
2. Carboxylic acid and halogenation of 5-chloropentanoic acid:
5-chloropentanoic acid reacts with phosphorous acid trichloride to produce 5-chloropentanoic acid chloride. It is then reacted with mercaptoethanol to form a mercaptoester, which can then be processed into a haloacid. Carboxylic acid and halogenation reactions and their detailed steps.
(1.) Carboxylic acid reaction of 5-Chlorovaleryl chloride
First, the carboxylic acid reaction of 5-Chlorovaleryl chloride requires the use of acetone-HCl.
Step 1: Add 5-Chlorovaleryl chloride and acetone to two dry round bottom flasks separately.
Step 2: Hydrogen chloride gas was pumped into one of the round bottom flasks and reacted at room temperature for 2 hours.
Step 3: Transfer the reaction mixture to a separatory funnel and extract the product with ether
Step 4: Add dilute hydrochloric acid solution, water and concentrated NaOH one by one, and finally the ether layer is dried with anhydrous sodium sulfuric acid and then distilled to obtain the final product 5-Chlorovaleryl chloride.
(2.) Halogenation reaction of 5-Chlorovaleryl chloride
The halogenation of 5-Chlorovaleryl chloride is carried out by phosphorus chloride.
Step 1: Put 5-Chlorovaleryl chloride and phosphorus chloride into the reaction flask, and insert the glass rod to stir.
Step 2: Add N,N-diethylformamide (DMF) according to the weight of phosphorus chloride, and continue mixing and stirring.
Step 3: Continue to add N,N-diethylformamide, stir, and control the temperature not to exceed 35°C.
Step 4: After completing the reaction, dilute the product with water.
Step 5: A small amount of sodium hydroxide was added, and the upper organic phase was extracted with ether.
Step 6: Dry the ether layer with anhydrous sodium sulfuric acid and carry out distillation to obtain the final product 5-Chlorovaleryl chloride.
Summarize:
The above are the steps of the carboxylic acid and halogenation reaction of 5-Chlorovaleryl chloride. These reactions are commonly used methods in organic chemistry. Through these reactions, a series of organic compounds can be synthesized, providing important means and methods for organic chemistry research.
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3. Carbonylation and halogenation of acetone:
First, we need to understand the carbonylation process of acetone. This process is used to convert the carbon-carbon double bond in the middle of acetone into a carbonyl group, therefore, during carbonylation, the molecular structure of acetone changes. The reaction equation of this process is as follows:
CH3COCH3 + H2O + H+ → CH3COCH2OH2+
In simple terms, when acetone is exposed to acidic conditions, it loses a hydroxyl ion and replaces it with a hydrogen ion. As a result, the degree of carbonylation of acetone will increase.
Now, we can start to explore the reaction of 5-Chlorovaleryl chloride and acetone. This process can be divided into two steps: the first step is the carbonylation of acetone, and the second step is the halogenation of 5-Chlorovaleryl chloride. Below is a description of the detailed steps.
The first step: carbonylation of acetone:
We'll do this step under acidic conditions, adding an alcohol as a catalyst. Any dilute acid solution, such as sulfuric or hydrochloric acid, can be used. Proceed as follows:
1. Mix acetone, hydrochloric acid and methanol. A 1:1:1 ratio is generally used, but can be scaled as needed.
2. Heat the mixture to the reaction temperature (generally about 80-100°C), and add some sulfuric acid catalyst to the mixture to accelerate the reaction rate.
3. After the reaction has been carried out for a certain period of time, we will dilute the mixture with water to purify the reaction product.
4. Use a separating funnel to separate the water and organic compounds.
Through this step, we can convert the C=C bond in acetone to a carbonyl group, thereby producing CH3COCH2OH2+, the homocarbonyl compound of acetone. This is very important for subsequent responses.
The second step: halogenation of 5-Chlorovaleryl chloride:
This step is to introduce 5-Chlorovaleryl chloride into the reaction system and react with the high carbonyl compound of acetone. Proceed as follows:
1. Mix the high carbonyl compound of acetone and 5-Chlorovaleryl chloride. Generally, 4.5 moles of acetone and 1 mole of 5-Chlorovaleryl chloride are used for mixing, but the specific ratio can be adjusted as needed.
2. Add the sodium carbonate catalyst and mix the reactants.
3. The mixture is then heated to reaction temperature (typically about 80-110°C).
4. During the reaction, the reactants will be halogenated through an acid-catalyzed reaction, and the final product will be formed at this time: 5-Chloro-3-oxopentanoyl chloride.
5. Finally, we dilute the resulting compound with water and separate the water from the organic compound by separation.
5-Chloro-3-oxopentanoyl chloride is an intermediate compound that can be used to synthesize other organic compounds. The reaction equation of the whole reaction process is as follows:
CH3COCH2OH2+ + C5H9ClO + Na2CO3 → C7H10ClO2 + CO2 + H2O + NaCl
This reaction equation covers the whole process of carbonylation of acetone and halogenation of 5-Chlorovaleryl chloride to obtain the final product.
4. Halogenation of 5-chloropentanol:
5-Chloropentanol was converted to 5-chloropentene with thionyl chloride. This material can then be converted to 5-chlorovaleralyl chloride by reaction with phosphorous acid trichloride followed by the addition of dichloromethane and diethyl tetraacetate to generate the 5-chlorovaleric acid haloacid. First, we need to prepare the laboratory necessities, including:
1. Reactor or round bottom flask (100 mL);
2. Sodium hydrochloride (NaCl) and hydrochloric acid (HCl);
3. 5-chloropentanol and anhydrous ferric chloride (FeCl3);
4. Aluminum oxide (Al2O3) and carbon tetrachloride (CCl4);
5. Ether solvents, water bath and ice bath.
Next, we start the halogenation step of 5-chloropentanol:
Step 1: Add 5-chloropentanol (1.0 mL, 10 mmol) into a dry round bottom flask;
Step 2: Add hydrochloric acid (2 mL, molar ratio 1:1) into a round bottom flask, warm it to room temperature for 15 minutes;
Step 3: Add 30% NaCl solution (2 mL) to the reactant, put it in a water bath to warm;
Step 4: After complete heating and stirring, use a separatory funnel to separate the aqueous layer and the organic layer, and collect the organic layer into a clean round bottom flask;
Step 5: Add anhydrous ferric chloride (5 g) and alumina (5 g) to a round bottom flask and stir at room temperature for 30 minutes;
Step 6: Add carbon tetrachloride (10 mL) for extraction, put a separatory funnel on the wooden stopper, separate the organic layer and the aqueous layer, and collect the organic layer into a clean round bottom flask;
Step 7: using concentrated hydrochloric acid solution to acidify the organic layer;
Step 8: Dissolving the organic matter in an ether solvent, filtering and drying;
Step 9: Use a rotary evaporator to remove the solvent to obtain 5-Chlorovaleryl chloride, a halogenated product of 5-chloropentanol.
Generally speaking, this reaction is relatively stable and safe, and the expected product can be obtained in the experiment. When conducting halogenation reactions, special care must be taken to avoid eye and skin contact with halides, and good ventilation must be provided. If any abnormal chemical reaction occurs in the reaction, stop the reaction immediately and take appropriate safety measures.
5. Halogenation reaction of bromobutyric acid:
The halogenation reaction of 5-Chlorovaleryl chloride and bromobutyric acid is a common organic synthesis reaction, and the reactive functional groups in their chemical structures can be used for substitution reactions to obtain new organic compounds.
The reaction steps are as follows:
(1.) Preparation of reactants: First, the reactants of 5-Chlorovaleryl chloride and bromobutyric acid need to be prepared. 5-Chlorovaleryl chloride can be prepared by chlorination of 5-Chlorovaleric acid and Thionyl chloride. Bromobutyric acid can be prepared by the substitution reaction of butanol and bromine.
(2.) Preparation of reaction solution: Dissolve the prepared 5-Chlorovaleryl chloride and bromobutyric acid in a dry organic solvent, such as dichloromethane or benzene, respectively.
(3.) Add catalyst: add an appropriate amount of catalyst, generally use sodium hydroxide or ferric chloride, etc.
(4.) Reaction process: Slowly add the two reaction liquids dropwise into the reactor, and heat the reaction. The reaction time is several hours, and the reaction temperature is generally controlled below the boiling point of the reactant.
(5.) Treatment at the end of the reaction: After the reaction, treat the reaction substance with cold water or hydrochloric acid solution to remove the reaction residue and catalyst. The resulting halogenated product was separated by extraction and separation, condensed and filtered to obtain a pure product.
The mechanism of the reaction is as follows: First, the catalyst further acidifies the carboxyl group of bromobutyric acid, thereby making it easier to be substituted. Secondly, the chloroalkyl group in 5-Chlorovaleryl chloride undergoes a substitution reaction with the carboxyl group in bromobutyric acid to produce a halogenated product. Finally, the solution was filtered to obtain the pure halogenated product.
The above are several main synthetic methods, all of which can obtain 5-Chlorovaleryl chloride. The choice of synthetic method also depends on the availability of reactants, cost, and equipment and chemicals available in the laboratory.