Looking for classes? Ksquare Career Institute, Bengaluru →
Aldehydes, Ketones and Carboxylic Acids
Friedel-Crafts Acylation and Grignard Reaction
1 question from 1 paper, each with its answer.
- question
- 1
- paper
- 1
- of Aldehydes, Ketones and Carboxylic Acids
- 1.1%
Concepts tested
- Acid chloride to ketone to tertiary alcohol
All Questions
2003 AIPMT 1 question
-
In a set of the given reactions, acetic acid yielded a product C.
$CH_3COOH + PCl_5 \rightarrow A \xrightarrow[Anh.\ AlCl_3]{C_6H_6} B \xrightarrow[ether]{C_2H_5MgBr} C$
Product C would beStep 1: $PCl_5$ converts acetic acid into acetyl chloride (A):
$CH_3COOH + PCl_5 \rightarrow CH_3COCl + POCl_3 + HCl$
Step 2: Friedel-Crafts acylation of benzene with acetyl chloride gives acetophenone (B):
$CH_3COCl + C_6H_6 \xrightarrow{anhyd.\ AlCl_3} CH_3COC_6H_5 + HCl$
Step 3: Ethylmagnesium bromide adds to the ketone; the ethyl group attacks the carbonyl carbon. Hydrolysis then gives a tertiary alcohol (C):
$CH_3COC_6H_5 + C_2H_5MgBr \rightarrow CH_3C(OMgBr)(C_2H_5)C_6H_5 \xrightarrow{H_2O} CH_3C(OH)(C_2H_5)C_6H_5$
So C is 2-phenylbutan-2-ol, $CH_3-C(OH)(C_2H_5)-C_6H_5$.