Experiment 4
To synthesis chlorbutanol from chloroform
Reference:
Bentley and driver’s textbook of pharmaceutical chemistry, oxford university press,
London page No. 343
Requirements:
1. Chloroform
2. Acetone
3. Potassium hydroxide
Principle: It is a trichloro derivative of tert. Butyl alcohol also known as chloritone
Chlorbutanol is formed by the simple nucleophilic addition of chloroform and acetone, this
reaction is base driven by potassium or sodium hydroxide. Alcoholic KOH is used in order to
accelerate the reaction towards formation of chlorbutanol
H3C CO CH3 + CHCl3 (alcoholic KOH) -------Cl3 C C OH (CH3)2 + H2O + KCl
Procedure:
1. In a dry conical flask put 5 mL of acetone with 2 mL of chloroform.
2. Cool the mixture.
3. Alcoholic solution is prepared from dissolving 0.35 g of KOH in the minimum amount of
ethanol (rectified spirit about 5mL).
4. Add alcoholic solution in step 3 to the mixture of step 2.
5. Filter the precipitated KCl and wash it twice with small portions of acetone. 6. Evaporate
in water bath.
7. Recrystallize from the mixture of water and ethanol
Uses: Hypnotic agent, used as preventive of sea sickness
Properties: It is white crystalline powder found in two forms: anhydrous and hydrated, also
it has characteristic camphor-like odour and taste. The melting point is 95-99 ºC and boiling
point is 167 ºC It is freely soluble in alcohol (1:1) slightly soluble in cold water (1:125) and
more soluble in boiling water but such high temperature may lead to hydrolysis of
chlorbutanol
