0
$\begingroup$

I've read articles online and they rarely mention about chlorination of benzaldehyde but more on bromination. Also, I would like to know the catalyst used for this is FeCl3 or AlCl3? Thanks for your help!:)

$\endgroup$
  • $\begingroup$ Homework? What does the literature say about the bromination? What does the literature say about using iron or aluminium chloride for other substrates? Please elaborate. $\endgroup$ – Karl Jan 3 '18 at 14:10
  • $\begingroup$ In my syllabus we only learnt about halogenation for benzene and toluene and its FeCl3 as the catalyst. However, I’m unsure if benzaldehyde is able to halogenate the same way as benzene and toluene. So thats my qns. $\endgroup$ – Crystal Jan 3 '18 at 14:21
  • $\begingroup$ Please edit your question accordingly, and make clear that you want the aromatic substitution, not the chloraldehyde. And a hint: FC-alkylation works with catalytic amounts of AlCl3, FC-acylation not. $\endgroup$ – Karl Jan 3 '18 at 16:29
1
$\begingroup$

The experimental process of chlorination of benzaldehyde to form benzoyl chloride can be found here:

enter image description here

A round bottom flask is fitted with a reflux condenser and a gas inlet tube. 100 grams of cold and dry benzaldehyde are added to the flask and saturated with the current of dry chlorine. The chlorine gas is readily absorbed and the evolution hydrogen chloride takes place. When the reaction has moderated, the external heat is applied by keeping gentle boiling. The stream of chlorine is continued until no more hydrogen chloride is evolved. A stream of dry air or carbon dioxide is then passed through the apparatus in order to remove an excess of chlorine. Benzoyl chloride is obtained by distillation as a colorless fuming liquid with a very irritating smell. Yield almost quantitative.

Preparation of organic compounds, E. de. Barry Barnett, 52, 1912

There is also a German paper written by Freidrich Wohler and Justus von Leibig which mentions an early preparation of benzoyl chloride by the action of chlorine over benzaldehyde.

$\endgroup$
  • $\begingroup$ I think the OP wanted to know about halogenation of benzene nucleus. $\endgroup$ – Shoubhik R Maiti Jan 3 '18 at 14:59
0
$\begingroup$

Bromine Chloride in the presence of AlCl3 reacts with benzaldehyde to give 3-Bromobenzaldehyde - see US Patent 4036887 A

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.