0
Why do you use acetanilide rather than aniline in the synthesis of 4-acetamidobenzenesulfonyl chloride?
Sulfanilamide has two groups on the benzene ring in para- positions to each other. The amino group is a highly activating ortho-directing group and the sulfonamide group is a meta-directing group.
Consequently, the amino group must be introduced first followed by the introduction of the sulfonamide group. To introduce the sulfonamide group one must first use chlorosulfonic acid then ammonium hydroxide.
Unfortunately, amino groups react with chlorosulfonic acid leading to undesired products and the direct chlorosulfonation of aniline would not lead to the desired intermediate product. However, if the amino group is converted to an amide, the undesired side reaction with chlorosulfonic acid is avoided. The acetyl group in this
case serves as a "protecting group" for the amine that allows a smooth chlorosulfonation of the benzene ring.
The amide nitrogen does not activate the ring towards substitution as much as the free amino group, but it can still exert its ortho/para- directing influence. In this case the steric hindrance provided by the acetyl group results in the substitution occurring predominantly at the para- substitution. The protecting acetyl group is removed later to give the desired "free" amino group. The protection of groups that would interfere with a given step in a synthesis is not uncommon, but I it is necessary for the "protecting group" to be introduced and removed readily by reactions that will not adversely affect other groups in the molecule.
REFERENCE: http://www.uwf.edu/chemistry/faculty/Gurst/SULFANIL.pdf Sulfanilamide has two groups on the benzene ring in para- positions to each other. The amino group is a highly activating ortho-directing group and the sulfonamide group is a meta-directing group.
Consequently, the amino group must be introduced first followed by the introduction of the sulfonamide group. To introduce the sulfonamide group one must first use chlorosulfonic acid then ammonium hydroxide.
Unfortunately, amino groups react with chlorosulfonic acid leading to undesired products and the direct chlorosulfonation of aniline would not lead to the desired intermediate product. However, if the amino group is converted to an amide, the undesired side reaction with chlorosulfonic acid is avoided. The acetyl group in this
case serves as a "protecting group" for the amine that allows a smooth chlorosulfonation of the benzene ring.
The amide nitrogen does not activate the ring towards substitution as much as the free amino group, but it can still exert its ortho/para- directing influence. In this case the steric hindrance provided by the acetyl group results in the substitution occurring predominantly at the para- substitution. The protecting acetyl group is removed later to give the desired "free" amino group. The protection of groups that would interfere with a given step in a synthesis is not uncommon, but I it is necessary for the "protecting group" to be introduced and removed readily by reactions that will not adversely affect other groups in the molecule.
REFERENCE: http://www.uwf.edu/chemistry/faculty/Gurst/SULFANIL.pdf Sulfanilamide has two groups on the benzene ring in para- positions to each other. The amino
group is a highly activating ortho-directing group and the sulfonamide group is a meta-directing group.
Consequently, the amino group must be introduced first followed by the introduction of the sulfonamide
group. To introduce the sulfonamide group one must first use chlorosulfonic acid then ammonium hydroxide.
Unfortunately, amino groups react with chlorosulfonic acid leading to undesired products and the direct
chlorosulfonation of aniline would not lead to the desired intermediate product. However, if the amino group is
converted to an amide, the undesired side reaction with chlorosulfonic acid is avoided. The acetyl group in this
case serves as a "protecting group" for the amine that allows a smooth chlorosulfonation of the benzene ring.
The amide nitrogen does not activate the ring towards substitution as much as the free amino group, but it can
still exert its ortho/para- directing influence. In this case the steric hindrance provided by the acetyl group
results in the substitution occurring predominantly at the para- substitution. The protecting acetyl group is
removed later to give the desired "free" amino group. The protection of groups that would interfere with a
given step in a synthesis is not uncommon, but I it is necessary for the "protecting group" to be introduced and
removed readily by reactions that will not adversely affect other groups in the molecule.
From: http://www.uwf.edu/chemistry/faculty/Gurst/SULFANIL.pdf
What else can I help you with?
What is the purpose of adding sodium acetate to the reaction mixture in preparation of acetanilide?
In the synthesis of acetanilide the hydrochloride salt of aniline is used in order to increase the solubility in water. The sodium acetate acts as a base and reacts with the HCl to produce acetic acid. Once the acetanilide product is no longer a hydrochloride salt, its solubility in water is decreased and it crystalises out. The main byproducts are sodium chloride and acetic acid which remain soluble in the water and are removed when the crude product is filtered off.
What is the reaction of benzoyl chloride with aniline?
Benzoyl chloride reacts with aniline to form N-phenylbenzamide. In the reaction, the chlorine atom of benzoyl chloride is replaced by the amino group of aniline. The reaction is often carried out in the presence of a base to help neutralize the hydrogen chloride byproduct.
What is the balanced equation for aniline with ferric chloride?
Aniline on heating with Ferric chloride forms Ferric anilide and HCl. 3C6H5-NH2 + FeCl3 = (C6H5-NH)3Fe + 3HCl
What is the product of a reaction between bromine and aniline in non polar solvent?
The product of a reaction between bromine and aniline in a non-polar solvent is typically the bromination of aniline, where bromine substitutes a hydrogen atom on the benzene ring of aniline to form bromoaniline. This reaction is an electrophilic aromatic substitution reaction.
What reagent you use to convert aniline into chlorobenzene?
You can convert aniline to chlorobenzene by reacting it with chlorine in the presence of a Lewis acid catalyst such as iron (III) chloride (FeCl3). The reaction proceeds via electrophilic aromatic substitution to replace the amino group with a chlorine atom on the benzene ring to form chlorobenzene.
What is the alternative route of synthesis of acetanilide?
Acetanilide can also be synthesized by reacting aniline with acetic anhydride, instead of acetyl chloride. This is known as the Acetic Anhydride Method.
Why do you use acetanilide rather aniline in the synthesis of p-nitroaniline?
Acetanilide is used instead of aniline in the synthesis of p-nitroaniline to control the selectivity of the reaction. Acetanilide is less reactive than aniline, making it easier to control the nitration process and avoid the formation of unwanted byproducts. Additionally, the acetanilide group can be easily removed after the nitration reaction to yield p-nitroaniline.
What reagents may be used for the preparation of acetanilide?
Acetanilide can be prepared using aniline and acetic anhydride as reagents. The reaction typically requires the presence of a catalyst, such as zinc chloride, to facilitate the acetylation of aniline to form acetanilide. The reaction is usually carried out in the presence of a base, like sodium acetate, to neutralize the acidic byproduct formed during the reaction.
Why add of little amount from acetic anhydride in synthesis of acetanilide?
Adding a small amount of acetic anhydride helps to facilitate the acetylation reaction with aniline, leading to the formation of acetanilide. The acetic anhydride serves as an acetylating agent that transfers an acetyl group to the amine group of aniline, resulting in the desired product. The use of an excess of acetic anhydride is avoided to prevent side reactions and to optimize the yield of acetanilide.
What is the role of the acetic anhydride in this reaction in the synthesis of acetanilide?
Acetic anhydride acts as an acetylating agent, adding an acetyl group to the amine group of aniline to form acetanilide. The acetyl group adds functionality to the aniline molecule, making it less basic and more soluble in organic solvents.
Is acetanilide an amide?
Yes, acetanilide is an amide. It is derived from aniline and acetic acid, containing the amide functional group (-CONH2).
What is an acetanilid?
An acetanilide is an amide derived from acetic acid and aniline, once used as an analgesic and antipyretic.
How do you convert c6h5nh2 to c6h5ococh3?
To convert aniline (C6H5NH2) to phenyl acetate (C6H5OCOCH3), you can follow these steps: First, acetylate aniline using acetic anhydride or acetyl chloride, which will replace the amino group with an acetyl group, forming acetanilide (C6H5NHCOCH3). Next, you can hydrolyze the acetanilide with an acid or base to yield phenyl acetate. This process involves replacing the amine group with an ester group, ultimately giving you C6H5OCOCH3.
What is the purpose of adding sodium acetate to the reaction mixture in preparation of acetanilide?
In the synthesis of acetanilide the hydrochloride salt of aniline is used in order to increase the solubility in water. The sodium acetate acts as a base and reacts with the HCl to produce acetic acid. Once the acetanilide product is no longer a hydrochloride salt, its solubility in water is decreased and it crystalises out. The main byproducts are sodium chloride and acetic acid which remain soluble in the water and are removed when the crude product is filtered off.
What is the reaction of benzoyl chloride with aniline?
Benzoyl chloride reacts with aniline to form N-phenylbenzamide. In the reaction, the chlorine atom of benzoyl chloride is replaced by the amino group of aniline. The reaction is often carried out in the presence of a base to help neutralize the hydrogen chloride byproduct.
What is the balanced equation for aniline with ferric chloride?
Aniline on heating with Ferric chloride forms Ferric anilide and HCl. 3C6H5-NH2 + FeCl3 = (C6H5-NH)3Fe + 3HCl
Why is there only one acyl group placed on aniline in the reaction forming acetanilide?
Actually it is possible to put a second acyl group on as well, for example with acetyl chloride and triethylamine. Under aqueous basic conditions the second acyl group is far more readily hydrolysed.
