Question

3. Rank the reactivity of the compounds shown below when using a Friedel Crafts alkylation reaction. Make sure you label which is least reactive and most reactive. (5 pts) 4. Provide a plausible mechanism for the reaction shown.(6 pts) =100

Answer 1

Q:3 The FRIEDEL CRAFTS alkylation reaction is an example for the Electrophilic Aromatic Substitution reaction,

1. The order of the reactivity of the given compounds towards the Friedel crafts alkylation reaction is D > C > A > B.

2. Where D is the most reactive and B is the least reactive.

3.Reason Behind their reactivity is due to both INDUCTIVE and RESONANCE effects.

4.The electrophilic substitution is greater for the compound D is due the presence of the OAc, group which highly increases the electron density on the benzene ring(ACTIVATION OF THE RING).

5.In compound B there presence both Br and -NO2 group which reduces the electron density on the benzene ring by withdrawing the electron density from the ring(DEACTIVATION OF THE RING). So the substitution reaction is much slower than the other three.

Q2: The above reaction is the Example for the ELIMINATION ADDITION REACTION.

Here the NaNH2 in Liq NH3 which acts as a strong base which can able to abstract the proton from benzene, which is adjacent to the leaving group carbon.
NANH2 WHəlli Ag (AS HY (BI Mechanism :- NANH, in lig, Why is a strong bare, which abstracts the proton from the benzene, that is adjacent to the promine carbon. And the elimination of Bromine occurs, H B - CH3 Benzyne NH Addition NH JH CHO [A] [B] A HON 10 HN Addition Η ΕΝΗ, [B]