Question

In the reaction, \[{{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}{\rm{CHO}} + {{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}{\rm{N}}{{\rm{H}}_{\rm{2}}} \to {{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}{\rm{N}} = {\rm{CH}}{{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}({\rm{A}}) + {{\rm{H}}_{\rm{2}}}{\rm{O}}\] the compound A is known as:
A. Aldol
B. Schiff base
C. Schiff reagent
D. Benedict’s reagent

Answer 1

Hint: A general compound possessing the general structure of \[{{\rm{R}}_{\rm{1}}}{{\rm{R}}_{\rm{2}}}{\rm{C}} = {\rm{N}}{{\rm{R}}^{'}}\] is termed Schiff base. The functional group carried by Schiff base is azomethine or imine (-C=N-). Schiff bases are formed when carbonyl compounds undergo a reaction with primary amine.

Complete Step by Step Solution:
The given reaction is,
\[{{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}{\rm{CHO}} + {{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}{\rm{N}}{{\rm{H}}_{\rm{2}}} \to {{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}{\rm{N}} = {\rm{CH}}{{\rm{C}}_{\rm{6}}}{{\rm{H}}_{\rm{5}}}({\rm{A}}) + {{\rm{H}}_{\rm{2}}}{\rm{O}}\]
Here, a carbonyl compound (Benzaldehyde) undergoes a reaction with a primary amine (aniline) to form Schiff base(A). The compound A formed is a Schiff base because it contains the imine functional group, that is, (-C=N-) .
Therefore, product A is a Schiff base. Hence, the option B is right.

Additional Information: Let’s understand what an aldol is. An aldol is a product formed when aldehydes or ketones possessing the \[\alpha \] hydrogen undergo a reaction in the basic medium. The aldols are beta hydroxyl aldehydes. It contains both aldehyde and alcohol as functional groups. Let’s understand the Schiff reagent. It is the chemical species obtained in the reaction of fuchsin and sodium bisulphite. It is useful in organic chemistry in the detection of the aldehyde functional group in an unknown sample.

Note: Benedict's reagent is a mixture of sodium citrate, copper(II) sulfate pentahydrate and sodium carbonate. It is an alternative to the Fehling solution in the detection of the presence of reducing sugars. On heating of sugar (glucose) with blue coloured Benedict’s solution, a yellow, red or orange coloured precipitate is obtained. This is how the presence of sugar is checked.