Organic Chemistry

Blazing goIITian

Joined: 7 May 2007
Post: 1724
12 Nov 2008 09:35:10 IST
0 People liked this
1
2941 View Post
MECHANISM OF BLANC REACTION-CHLOROMETHYLATION OF BENZENE
Engineering Entrance , Medical Entrance , NEET , JEE Main , AIIMS , JEE Main & Advanced , Chemistry , Organic Chemistry

MECHANISM OF BLANC REACTION-CHLOROMETHYLATION OF BENZENE  FOR EXPERTS



Comments (1)

Madhusudan Chavan's Avatar

Forum Expert
Joined: 9 Mar 2007
Posts: 2821
12 Nov 2008 20:29:40 IST
1 people liked this

This is a process whereby a hydrogen atom is replaced by a chloromethyl group, CH2Cl. The reaction may be carried out by heating the aromatic hydrocarbon with formalin or paraformaldehyde and hydrochloric acid in the presence of zinc chloride as catalyst, e.g., benzyl chloride from benzene :


                                    ZnCl2


C6H6 + CH2O + HCl  ........> C6H5CH2Cl + H2O


The mechanism of chloromethylation is uncertain; a possibility is :


                                                                                                         ArH                         HCl


2CH2=O  + 2HCl  + ZnCl2  <......>[ZnCl4] 2-     + 2  [+CH2OH]  ........>ArCH2OH .......> ArCH2Cl


2- after ZnCl4 and +before CH2OH are charges on these species., first step arrows are for reversible reaction.




Quick Reply


Reply

Some HTML allowed.
Keep your comments above the belt or risk having them deleted.
Signup for a avatar to have your pictures show up by your comment
If Members see a thread that violates the Posting Rules, bring it to the attention of the Moderator Team
Free Sign Up!
Sponsored Ads

Preparing for JEE?

Kickstart your preparation with new improved study material - Books & Online Test Series for JEE 2014/ 2015


@ INR 5,443/-

For Quick Info

Name

Mobile

E-mail

City

Class

Vertical Limit

Top Contributors
All Time This Month Last Week
1. Bipin Dubey
Altitude - 16545 m
Post - 7958
2. Himanshu
Altitude - 10925 m
Post - 3836
3. Hari Shankar
Altitude - 10085 m
Post - 2217
4. edison
Altitude - 10825 m
Post - 7804
5. Sagar Saxena
Altitude - 8635 m
Post - 8064
6. Yagyadutt Mishr..
Altitude - 6330 m
Post - 1958

Find Posts by Topics

Physics

Topics

Mathematics

Chemistry

Biology

Parents Corner

Board

Fun Zone