25 Attacking Reagents Electrophile Nucleophile For Class 11th Bsc I Neet Jee And All Examination

Electrophile and Nucleophile (Attacking and Reaction Reagent)

Introduction To Reaction Mechanism|Substrate And Reagent|Attacking Reagent|Electrophiles|Nucleophiles|Questions|Summary

Class 11 Board VS JEE VS NEET

(a) Account for the following : (i) Propanal is more reactive than propanone towards nucleophilic reagents. (ii) Electrophilic substitution in benzoic acid taken place at meta position. (iii) Carboxylic acids do not distinguish between the following pairs of compounds : (b) Give simple chemical test to distinguish between the following pairs of compounds : (i) Acetophenone and benzaldehyde (ii) Benzoic acid and ethylbenzoate.

The -NO_(2) group in an aromatic ring deactivates the ortho and para positions for an electrophilic attack. When -NO_(2) group is present at ortho or para positions of a leaving group (Nucleofuge) it activates the ring for nucleophilic attack. The reduction of -NO_(2) group by metal in acid causes its reduction to -NH_(2) group and then the ring becomes strongly activated for a electrophilic attack. The strong activation of -NH_(2) group is moderated by its acylation with CH_(3)COCl to -NHAc group. Deacylation is carried out by hydrolysis with H_(3)O^(+) or OH^(-) . The ring alkylation by using RX//AlX_(3) is not possible in presence of -NO_(2) or -NH_(2) group but is possible in presence of -NHAc group. The product (I) is :