R-C(=O)H + R-NH_2 rightarrow R-CH=N-R. This r | vedclass

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(B) The reaction of an aldehyde or ketone with a primary amine to form an imine is an acid-catalyzed process.At very low $pH$ (highly acidic),the amin

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$pH \, 4 - 5$

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(B) The reaction of an aldehyde or ketone with a primary amine to form an imine is an acid-catalyzed process.At very low $pH$ (highly acidic),the amine $(R-NH_2)$ gets protonated to form the ammonium ion $(R-NH_3^+)$,which is no longer nucleophilic,thus slowing down the reaction.At very high $pH$ (basic),there is insufficient acid to catalyze the dehydration step,which involves the conversion of a poor leaving group $(-OH)$ into a good leaving group $(-OH_2^+)$.Therefore,the reaction proceeds with the best yield at a mildly acidic $pH$ range of $4 - 5$,which provides enough acid to catalyze the dehydration without fully protonating the amine.

$R-C(=O)H + R-NH_2 \rightarrow R-CH=N-R$. This reaction gives the best yield at:

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