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write the methods of preparation of amino acid.

write the methods of preparation of amino acid. 

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2 Answers

Aman Bansal
592 Points
12 years ago

Dear Nikulas,

Methods of preparation of amino acids:         

 
 

(i)            Elimination of α - haloacids.

 
 
      Cl – CH2COOH + 2NH3 ———> H2NCH2COOH + NH4Cl
                                                           Glycine
 
 

(ii)          Gabriel phthalimide synthesis:

 

α halogenated acid or ester combines with potassium phthalimide. Product on hydrolysis gives α - amino acid.

 

90_Phthalic acid.JPG           

 

(iii) Knoop synthesis:

 

α - keto acid on treatment with NH3 forms an imine which on catalytic reduction gives amino acid.

 

      479_Pyruric acid.JPG

 

(iv) Strecker synthesis:

 

Aldehydes react with HCN and ammonia or NH4CN and the product on hydrolysis yields α - aminoacids.

 

 

        H                               H                                     H                                 H
        |          HCN                |                   NH3              |             H2O.H+           |
R — C = O ———> R —— C —— OH ———> R —— C — NH2 ———> R —— C —— NH2
 
 
                                         |                                       |                                   |
     Aldehyde                    CN                                   CN                             COOH
                                 Cyanohydrin                       Aminonitrile                 α - amino acid

 

 

Some of the reactions given by amino acids are as follows:

 

               2357_Amino acid reaction.JPG

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Aman Bansal

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Rishi Sharma
askIITians Faculty 646 Points
3 years ago
Dear Student,
Please find below the solution to your problem.
Methods of preparation of amino acids:
(i)Elimination of α - haloacids.
645-703_027.PNG
(ii)Gabriel phthalimide synthesis:α-halogenatedacid or ester combines with potassium phthalimide. Product on hydrolysis givesα - amino acid.
645-1236_0027.PNG
(iii)Knoop synthesis:α -keto acid on treatment with NH3forms an imine which on catalytic reduction gives amino acid.
645-991_00027.PNG
Thanks and Regards

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