Reaction Equation Help: Pentan 3 One + 2,4-Dinitrophenylhydrazine Formula

  • Thread starter Thread starter newkidintownu
  • Start date Start date
  • Tags Tags
    Reaction
Click For Summary
SUMMARY

The discussion centers on the reaction between pentan-3-one and 2,4-dinitrophenylhydrazine (DNP), specifically addressing the formation of a DNP derivative and its implications in organic chemistry. The Wolff-Kishner reduction, which typically follows the reaction of a ketone with hydrazine, is clarified as not applicable to DNP derivatives. Instead, the formation of the DNP derivative itself is confirmed to be the focus of Brady's test, which indicates the presence of ketone carbonyls through the formation of a yellow or red precipitate. The distinction between the Wolff-Kishner reduction and Brady's test is emphasized, highlighting their different roles in organic synthesis.

PREREQUISITES
  • Understanding of organic chemistry concepts, particularly ketones and aldehydes
  • Familiarity with the Wolff-Kishner reduction mechanism
  • Knowledge of the Brady's test for carbonyl detection
  • Basic grasp of hydrazine chemistry and its derivatives
NEXT STEPS
  • Study the mechanism of the Wolff-Kishner reduction in detail
  • Research the application and significance of Brady's test in organic synthesis
  • Explore the properties and reactions of 2,4-dinitrophenylhydrazine
  • Investigate the role of hydrazine derivatives in organic reactions
USEFUL FOR

Chemistry students, organic chemists, and researchers involved in ketone and aldehyde analysis will benefit from this discussion, particularly those interested in reaction mechanisms and carbonyl detection methods.

newkidintownu
Messages
5
Reaction score
0
Please can someone help me.

I need to write an equation for the reaction between pentan 3 one and 2,4-dinitrophenylhydrazine.

I am not very good with this area of chemistry so any help will be much appreciated.

Ta
 
Physics news on Phys.org
Last edited:
bomba923 said:
Hint: Wolff-Kishner

(Edit: this probably belongs in the Homework Help/Other Sciences forum)

The Wolff-Kishner reaction is the reduction that (typically) follows this reaction of a ketone with hydrazine (H2N2H2). I'm not sure it works on a DNP derivative, though. DNP derivatives are usually employed for melting point determinations.
 
chemisttree said:
The Wolff-Kishner reaction is the reduction that (typically) follows this reaction of a ketone with hydrazine (H2N2H2). I'm not sure it works on a DNP derivative, though. DNP derivatives are usually employed for melting point determinations.
DNP-hydrazine (from the OP) is used to test exclusively for the presence of ketone carbonyls within a molecule via the general Wolff-Kishner reduction. This procedure is known as Brady's Test, which is positive upon formation of a yellow or red precipitate (see Analyst, 1926, 51, 77 - 78, DOI: 10.1039/AN9265100077)
 
Last edited:
bomba923 said:
DNP-hydrazine (from the OP) is used to test exclusively for the presence of ketone carbonyls within a molecule via the general Wolff-Kishner reduction. This procedure is known as Brady's Test, which is positive upon formation of a yellow or red precipitate (see Analyst, 1926, 51, 77 - 78, DOI: 10.1039/AN9265100077)

That's almost correct. Brady's test is specifically the formation of the DNP derivative itself (both ketones and aldehydes)... not it's further reduction to the alkane if only hydrazine itself were used (Wolff-Kishner Reduction).

The Wolff-Kishner reduction is a specific reaction utilizing an aldehyde or ketone and hydrazine (NOT 2,4-DNP a different 'hydrazine') and a strong base to yield an alkane. Wolff-Kishner is NOT Brady's test. Some elements of the chemistry are similar, however.
 
chemisttree said:
That's almost correct. Brady's test is specifically the formation of the DNP derivative itself (both ketones and aldehydes)... not it's further reduction to the alkane if only hydrazine itself were used (Wolff-Kishner Reduction).

The Wolff-Kishner reduction is a specific reaction utilizing an aldehyde or ketone and hydrazine (NOT 2,4-DNP a different 'hydrazine') and a strong base to yield an alkane. Wolff-Kishner is NOT Brady's test. Some elements of the chemistry are similar, however.
Indeed--I should have first looked this up on Wikipedia!
http://en.wikipedia.org/wiki/2,4-Dinitrophenylhydrazine
(even at best, the most convenient reference for this concept)

--Accordingly, no reduction occurs but rather the precipitation of the DNP-derivative
itself and yes, aldehydes as well as ketones are detected by Brady's test
 
Last edited:

Similar threads

  • · Replies 10 ·
Replies
10
Views
3K
Replies
3
Views
2K
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
7K
  • · Replies 9 ·
Replies
9
Views
7K
Replies
10
Views
5K
  • · Replies 6 ·
Replies
6
Views
4K
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K