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Hydrolysis of nitriles: Amide vs Carboxylic acid
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Michel Paul
Hydrolysis of nitriles: Amide vs Carboxylic acid
Yes, you are correct. For converting a nitrile to amide, we do controlled hydrolysis.
So, first amide is obtained and then ammonium salt of the carboxylic acid is obtained.
So, the reaction would be $$\ce{RCN}+2 \ce{H_2O_2}+\ce{OH^{-1}} \ce{->} \ce{RCONH_2} +\ce{O_2}+\ce{H_2O}$$
Which is done at $\mathrm{pH}$ range of 7-8.
If you increase or decrease the $\mathrm{pH}$ more than this, you will get the acid.
Additional Reading:
Mcisaac, J. E.; Ball, R. E.; Behrman, E. J. Mechanism of the base-catalyzed conversion of nitriles to amides by hydrogen peroxide. J. Org. Chem.1971,36 (20), 3048–3050. DOI: 10.1021/jo00819a034.
Yes, you are correct. For converting a nitrile to amide, we do controlled hydrolysis.
So, first amide is obtained and then ammonium salt of the carboxylic acid is obtained.
So, the reaction would be $$\ce{RCN}+2 \ce{H_2O_2}+\ce{OH^{-1}} \ce{->} \ce{RCONH_2} +\ce{O_2}+\ce{H_2O}$$
Which is done at $\mathrm{pH}$ range of 7-8.
If you increase or decrease the $\mathrm{pH}$ more than this, you will get the acid.
Additional Reading:
Mcisaac, J. E.; Ball, R. E.; Behrman, E. J. Mechanism of the base-catalyzed conversion of nitriles to amides by hydrogen peroxide. J. Org. Chem.1971,36 (20), 3048–3050. DOI: 10.1021/jo00819a034.
I understand the hydrolysis of nitriles using alkaline H2O2,the question was about the acid hydrolysis of nitriles.Thanks for answering! BTW,are you the same Light Yagami on AoPS?More
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Hydrolysis of nitrile is pH dependent. It will lead to formation of different products based on pH.
Theoretically, nitrile hydrolyze to form amide and then ammonium salt.
$$\ce{RCN ->[H2O] RCONH2 ->[H2O] RCOONH4}$$
But in practice, the reaction between nitriles and water is so slow that it is considered negligible. The nitrile is instead heated with either a dilute acid such as dilute hydrochloric acid, or with an alkali such as sodium hydroxide solution to accelerate the hydrolysis reaction. But this pH dependent reaction yields different products.
Acid hydrolysis: yields carboxylic acid
$$\ce{RCN + 2H2O + HCl -> RCOOH + NH4Cl}$$
Alkaline hydrolysis: yields sodium carboxylate salt
$$\ce{RCN + H2O + NaOH-> RCOONa + NH3}$$
To obtain amide, hydrolysis is done selectively and in controlled manner. It can be done in both acidic and alkaline medium. In acidic medium, nitriles are converted into amide in a single step process using TFA-$\ce{H2SO4}$ mixture as reagent.
In alkaline medium, it can done using alkaline solution of hydrogen peroxide (see @Light Yagami's answer).
Facile and Highly Selective Conversion of Nitriles to Amides via Indirect Acid-Catalyzed Hydration Using TFA or AcOH−H2SO4, Jarugu Narasimha Moorthy and Nidhi Singhal, The Journal of Organic Chemistry 2005 70 (5), 1926-1929
DOI: 10.1021/jo048240a
Hydrolysis of nitrile is pH dependent. It will lead to formation of different products based on pH.
Theoretically, nitrile hydrolyze to form amide and then ammonium salt.
$$\ce{RCN ->[H2O] RCONH2 ->[H2O] RCOONH4}$$
But in practice, the reaction between nitriles and water is so slow that it is considered negligible. The nitrile is instead heated with either a dilute acid such as dilute hydrochloric acid, or with an alkali such as sodium hydroxide solution to accelerate the hydrolysis reaction. But this pH dependent reaction yields different products.
Acid hydrolysis: yields carboxylic acid
$$\ce{RCN + 2H2O + HCl -> RCOOH + NH4Cl}$$
Alkaline hydrolysis: yields sodium carboxylate salt
$$\ce{RCN + H2O + NaOH-> RCOONa + NH3}$$
To obtain amide, hydrolysis is done selectively and in controlled manner. It can be done in both acidic and alkaline medium. In acidic medium, nitriles are converted into amide in a single step process using TFA-$\ce{H2SO4}$ mixture as reagent.
In alkaline medium, it can done using alkaline solution of hydrogen peroxide (see @Light Yagami's answer).
Facile and Highly Selective Conversion of Nitriles to Amides via Indirect Acid-Catalyzed Hydration Using TFA or AcOH−H2SO4, Jarugu Narasimha Moorthy and Nidhi Singhal, The Journal of Organic Chemistry 2005 70 (5), 1926-1929DOI: 10.1021/jo048240a
Yes, you are correct. For converting a nitrile to amide, we do controlled hydrolysis.
So, first amide is obtained and then ammonium salt of the carboxylic acid is obtained.
So, the reaction would be $$\ce{RCN}+2 \ce{H_2O_2}+\ce{OH^{-1}} \ce{->} \ce{RCONH_2} +\ce{O_2}+\ce{H_2O}$$
Which is done at $\mathrm{pH}$ range of 7-8.
If you increase or decrease the $\mathrm{pH}$ more than this, you will get the acid.
Additional Reading:
Mcisaac, J. E.; Ball, R. E.; Behrman, E. J. Mechanism of the base-catalyzed conversion of nitriles to amides by hydrogen peroxide. J. Org. Chem. 1971, 36 (20), 3048–3050. DOI: 10.1021/jo00819a034.
The Hydrolysis of Nitriles: Chem Libretexts
Yes, you are correct. For converting a nitrile to amide, we do controlled hydrolysis.
So, first amide is obtained and then ammonium salt of the carboxylic acid is obtained.
So, the reaction would be $$\ce{RCN}+2 \ce{H_2O_2}+\ce{OH^{-1}} \ce{->} \ce{RCONH_2} +\ce{O_2}+\ce{H_2O}$$
Which is done at $\mathrm{pH}$ range of 7-8.
If you increase or decrease the $\mathrm{pH}$ more than this, you will get the acid.
Additional Reading:
Mcisaac, J. E.; Ball, R. E.; Behrman, E. J. Mechanism of the base-catalyzed conversion of nitriles to amides by hydrogen peroxide. J. Org. Chem. 1971, 36 (20), 3048–3050. DOI: 10.1021/jo00819a034.
The Hydrolysis of Nitriles: Chem Libretexts
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Hydrolysis of nitrile is pH dependent. It will lead to formation of different products based on pH.
Theoretically, nitrile hydrolyze to form amide and then ammonium salt.
$$\ce{RCN ->[H2O] RCONH2 ->[H2O] RCOONH4}$$
But in practice, the reaction between nitriles and water is so slow that it is considered negligible. The nitrile is instead heated with either a dilute acid such as dilute hydrochloric acid, or with an alkali such as sodium hydroxide solution to accelerate the hydrolysis reaction. But this pH dependent reaction yields different products.
$$\ce{RCN + 2H2O + HCl -> RCOOH + NH4Cl}$$
$$\ce{RCN + H2O + NaOH-> RCOONa + NH3}$$
To obtain amide, hydrolysis is done selectively and in controlled manner. It can be done in both acidic and alkaline medium. In acidic medium, nitriles are converted into amide in a single step process using TFA-$\ce{H2SO4}$ mixture as reagent.
In alkaline medium, it can done using alkaline solution of hydrogen peroxide (see @Light Yagami's answer).
Reference
Hydrolysis of nitrile is pH dependent. It will lead to formation of different products based on pH.
Theoretically, nitrile hydrolyze to form amide and then ammonium salt.
$$\ce{RCN ->[H2O] RCONH2 ->[H2O] RCOONH4}$$
But in practice, the reaction between nitriles and water is so slow that it is considered negligible. The nitrile is instead heated with either a dilute acid such as dilute hydrochloric acid, or with an alkali such as sodium hydroxide solution to accelerate the hydrolysis reaction. But this pH dependent reaction yields different products.
$$\ce{RCN + 2H2O + HCl -> RCOOH + NH4Cl}$$
$$\ce{RCN + H2O + NaOH-> RCOONa + NH3}$$
To obtain amide, hydrolysis is done selectively and in controlled manner. It can be done in both acidic and alkaline medium. In acidic medium, nitriles are converted into amide in a single step process using TFA-$\ce{H2SO4}$ mixture as reagent.
In alkaline medium, it can done using alkaline solution of hydrogen peroxide (see @Light Yagami's answer).
Reference
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