Which of the following would not give 2-phenylbutane as the major product in a friedel craft alkylation reaction?
1. 1-butene + HF
2. 2-butanol + H2SO4
3. butanoylchloride + AlCl3, then Zn, HCl
4. Butyl chloride + AlCl3
Ans. : (3)
The reagents in option 3 suggest, Friedel Crafts Acylation and not Alkylation.
2-phenyl Butane has the following structure,
If we use butanoyl Chloride i.e. CH3-CH2-CH2-CO-Cl the product we will get is, Phenyl propyl ketone
(Ph-CO-CH2-CH2-CH3)
Which upon reduction with Zn/HCl, will give you 1-Phenyl Butane,
This is not the desired product.
2-phenyl Butane has the following structure,
If we use butanoyl Chloride i.e. CH3-CH2-CH2-CO-Cl the product we will get is, Phenyl propyl ketone
(Ph-CO-CH2-CH2-CH3)
Which upon reduction with Zn/HCl, will give you 1-Phenyl Butane,
This is not the desired product.