Give the mechanism of the reaction between sodium bisulfate and benzaldehyde

Answer 1

The reaction between sodium bisulfate and benzaldehyde proceeds as follows:

1. The sodium bisulfate (NaHSO4) dissociates in water to form sodium ions (Na+) and bisulfate ions (HSO4-):

NaHSO4 → Na+ + HSO4-

2. The bisulfate ion reacts with the benzaldehyde (C6H5CHO) through an addition-elimination mechanism to form an intermediate:

HSO4- + C6H5CHO → C6H5CH(OHSO3-)OH

3. The intermediate then undergoes elimination of water to form the final product, benzoic acid (C6H5COOH) and sulfurous acid (H2SO3):

C6H5CH(OHSO3-)OH → C6H5COOH + H2SO3

Overall, the reaction can be summarized as:

NaHSO4 + C6H5CHO → C6H5COOH + H2SO3 + Na+

This reaction is a sulfonation process that introduces a sulfoxy group (-SO3H) into the benzaldehyde molecule, resulting in the formation of benzoic acid.