Acetone

Acetone

source : 123RF.com

Physical properties:

  1. Acetone is colorless,sweet smelling ,volatile liquid.
  2. It is soluble in water,alcohol & ether.
  3. Its boiling point is 560C.

 Chemical properties of Acetone :

1) Halogenation  —

 In this reaction hydrogen atoms of alkyl group are replaced by halogen atoms . [Formaldehyde do not give this reaction]

CH3COCH3 + 3Cl2 —->  CCl3 CO CH3 [Tri chloro acetone] + 3HCl

2) Aldol Condensation –

 It is a reaction in which two or more molecules of same or different carbonyl compounds containing alpha hydrogen atom, unite together in presence of dilute base such as NaOH,Ba(OH)2,K2CO3 etc.to form compounds called ALDOL.

a)   Two molecules of Acetone condense together in presence of  Ba(OH)2  to form di acetone alcohol or aldol.

(CH3)2 C=O + HCH2CO CH3 —–>(CH3)2C(OH)CH2CO CH3 [ di acetone alcohol or aldol ]

When  Diacetone alcohol  is  heated in presence of  little amount of iodine , mesityl oxide is formed .

(CH3)2C(OH)CH2CO CH3 ——->  (CH3)2C=CHCO CH3 [mesityl oxide] + H2O

b) When acetone saturated with HCl gas is kept at low temperature  for few days, it forms mesityl oxide & phorone which can be separated  by distillation .

(CH3)2 C=O + H2 CH COCH3 ——–>   (CH3)2 C= CH COCH3  [mesityl oxide] +H2O

(CH3)2 C=O + H2 CH CO CH H2  + O=C (CH3)2 ——->  (CH3)2 C= CH CO CH =C (CH3)2  [ phorone]+2H2O

c) When acetone is distilled with conc. H2SO4, it forms mesitylene .

source : commons.wikimedia.org

3) Reaction with ammonia-

          Acetone  forms diacetone amine [ i.e.  complex ketonic amines]

(CH3)2 C=O + H NH2 + HCH2 CO CH3 ——>  (CH3)2C(NH2) CH2 COCH3 [diacetone amine]+ H2O

4) Reaction with chloroform –

Acetone reacts with  chloroform to give  chloretone.

(CH3)2 C=O + CHCl3 ——>   (CH3)2 C (OH) CCl3 [chloretone]

5) Formation of Sodio derivatives-

            It  forms sodio- derivatives  when treated with  sodium or sodamide in ether solution.

CH3 CO CH3 + NaNH2 ——> CH3 CO CH2 Na [sodium derivative of acetone] + NH3

6) Reduction to Pinacols-

When ketones are reduced with Mg/Hg & H2O  in neutral or alkaline solution, pinacols are the main product.

(CH3)2 C=O +2[H] + O=C(CH3)2 ——>  (CH3)2 C (OH)C(OH)(CH3)2  [pinacol]

7) Reaction with Bleaching Powder-

Acetone forms chloroform when heated with bleaching powder.

CaOCl2 +H2O —–> Ca(OH)2 +Cl2

CH3COCH3 + 3CI2 —> C Cl3 CO CH3 + 3HCl

2CCl3 CO CH3 + Ca(OH)2 —-> 2CH Cl3 [chloroform] + ( CH3COO)2Ca