Why do not Friedel-Crafts reactions succeed on aromatic rings that are substituted either by a strongly electron-withdrawing group such as carbonyl (C=O) or by an amino group (-NH2, NHR, -NR2):

We Know that acyl groups or any electron withdrawing group present at ring which deactivating as result further substitution does not take place

While in case of Aniline or its derivatives, the Friedel Craft reaction occurs in the presence of aluminium chloride which is Lewis acidic and the Aniline is a strong base. Therefore, when aniline is reacted with aluminium chloride in Friedel-Craft’s reaction, formation of salt takes place. On which the presence of positive charge on nitrogen deactivates the benzene ring towards electrophilic aromatic substitution reactions. Therefore, aniline does not undergo Friedel-Craft’s reaction

Similar Questions:

Why does not aniline undergo Friedel crafts reactions explain?

Why Friedel–Crafts alkylations often give polysubstitution products but Friedel–Crafts acylations do not.

Why does not aniline undergo Friedel crafts reactions explain?

We know that the Friedel Craft reaction occurs in the presence of aluminium chloride which is Lewis acidic and the Aniline is a strong base. Therefore, when aniline is reacted with aluminium chloride in Friedel-Craft’s reaction, formation of salt takes place. The  salt formation take place as:

The presence of positive charge on nitrogen deactivates the benzene ring towards electrophilic aromatic substitution reactions. Therefore, aniline does not undergo Friedel-Craft’s reaction.

Similar Questions:

Why Friedel–Crafts alkylations often give polysubstitution products but Friedel–Crafts acylations do not.

Why Friedel–Crafts alkylations often give polysubstitution products but Friedel–Crafts acylations do not.

Alkyls groups are electron donating hence activating benzene ring for further alkylation as result polysubstituted product is obtained. While acyl groups are electron withdrawing and ring deactivating as result further substitution does not take place

Write the Dehydration and ring expansion mechanism of following alcohol:

This reaction proceed via carbocation  intermediate  formation and ring expansion in which  a molecule of water is lost in presence of concentrate Sulphuric acid. The initially formed primary carbocation rearranges to more stable secondary carbocation which results in ring expansion.

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Write Dehydration and ring expansion mechanism of 1-cyclobutylethanol in the presence of con H2SO4.

Write Dehydration and ring expansion mechanism of 1-cyclobutylethanol in the presence of con H2SO4.

Related Examples:
Explain Dehydration and ring expansion mechanism of 1-(1-Methylcyclopentyl)ethan-ol?
Explain the ring expansion mechanism of Bicyclic 1,2-Diols which undergoes pinacol pinacolone mechanism?