Which statement about the pH dependence of the reaction of a ketone with a primary amine to give an imine, R2C=O + R^pri

Question

Which statement about the pH dependence of the reaction of a ketone with a primary amine to give an imine, R2C=O + R^primeNH2 -> R2C=NR^prime + H2O, is correct?

Accepted Answer

At pH 1 the rate is low because most of the amine is converted to R^primeNH3+; at pH 11 the rate is low because the dehydration of the carbinolamine lacks acid catalysis

Answer

The rate is independent of pH because both steps are uncatalysed

Answer

At pH 1 the rate is low because the carbinolamine does not form from the ketone; at pH 11 the rate is low because the amine is protonated

Answer

The rate increases steadily as pH is lowered because carbonyl protonation is rate-determining at all pH

Which statement about the pH dependence of the reaction of a ketone with a primary amine to give an imine, $R X_{2} C = O + R X^{'} NH X_{2} R X_{2} C = NR X^{'} + H X_{2} O$ , is correct?

Answer: C

More questions on Nucleophilic addition to aldehydes and ketones

Which statement about the pH dependence of the reaction of a ketone with a primary amine to give an imine, RX2​C=O+RX′NHX2​​RX2​C=NRX′+HX2​O, is correct?

Answer: C

More questions on Nucleophilic addition to aldehydes and ketones

Which statement about the pH dependence of the reaction of a ketone with a primary amine to give an imine, $R X_{2} C = O + R X^{'} NH X_{2} R X_{2} C = NR X^{'} + H X_{2} O$ , is correct?