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How can benzyl chloride and ammonia be used to synthesize phenylalanine, and what conditions must be maintained in order to achieve a high yield of the desired product?

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To synthesize phenylalanine from benzyl chloride and ammonia, you can follow a two-step process involving the formation of an intermediate product, N-benzyl amine, followed by a Strecker synthesis to obtain phenylalanine.Step 1: Formation of N-benzyl amineBenzyl chloride  C6H5CH2Cl  can react with ammonia  NH3  to form N-benzyl amine  C6H5CH2NH2  as an intermediate product. This reaction is a nucleophilic substitution, where the ammonia acts as a nucleophile and attacks the electrophilic carbon in benzyl chloride, replacing the chlorine atom.C6H5CH2Cl + NH3  C6H5CH2NH2 + HClTo achieve a high yield of N-benzyl amine, the reaction should be carried out in anhydrous conditions, as water can hydrolyze benzyl chloride. Additionally, using an excess of ammonia can help drive the reaction to completion.Step 2: Strecker synthesisThe Strecker synthesis is a method for synthesizing amino acids from an amine, an aldehyde, and hydrogen cyanide  HCN . In this case, N-benzyl amine will be used as the amine, and formaldehyde  HCHO  will be used as the aldehyde.The reaction proceeds as follows:1. N-benzyl amine reacts with formaldehyde to form an imine intermediate.2. The imine intermediate reacts with hydrogen cyanide to form an -aminonitrile.3. The -aminonitrile is hydrolyzed to form phenylalanine.C6H5CH2NH2 + HCHO + HCN  C6H5CH NH2 CH2CN  C6H5CH NH2 COOH  Phenylalanine To achieve a high yield of phenylalanine, the Strecker synthesis should be carried out under controlled conditions. The reaction should be performed at low temperatures  0-5C  to minimize side reactions and decomposition of hydrogen cyanide. An excess of formaldehyde and hydrogen cyanide should be used to drive the reaction to completion. The hydrolysis of the -aminonitrile can be performed under acidic or basic conditions, but acidic hydrolysis is generally preferred to avoid racemization of the amino acid.After the synthesis is complete, the product can be purified by methods such as crystallization or chromatography to obtain pure phenylalanine.

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