Difference between revisions of "Hydrazone"

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(Preparation)
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==Preparation==
 
==Preparation==
Substituted hydrazines will react directly with carbonyl compounds to form the corresponding hydrazone.<ref>{{OrgSynth | first1 = G. | last1 = Stork | first2 = J. | last2 = Benaim | title = Monoalkylation of α,β-Unsaturated Ketones ''via'' Metalloenamines: 1-butyl-10-methyl-Δ<sup>1(9)</sup>-2-octalone | collvol = 6 | collvolpages = 242 | volume = 57 | pages = 69 | year = 1977}}.</ref> The reaction follows the normal [[addition–elimination mechanism]] for reactions at carbonyl carbon, and is [[Acid catalysis|acid-catalyzed]].
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Substituted hydrazines will react directly with carbonyl compounds to form the corresponding hydrazone.<ref>{{OrgSynth | first1 = G. | last1 = Stork | first2 = J. | last2 = Benaim | title = Monoalkylation of α,β-Unsaturated Ketones ''via'' Metalloenamines: 1-butyl-10-methyl-Δ<sup>1(9)</sup>-2-octalone | collvol = 6 | collvolpages = 242 | volume = 57 | pages = 69 | year = 1977 | prep = cv6p0242}}.</ref> The reaction follows the normal [[addition–elimination mechanism]] for reactions at carbonyl carbon, and is [[Acid catalysis|acid-catalyzed]].
  
 
The direct reaction cannot be used with [[hydrazine]] itself, as the hydrazone that is initially formed will react with a second equivalent of the carbonyl compound to form an [[azine]]. However the azine can be isolated, and then reacted with excess hydrazine to reform the hydrazone.<ref name="acetone">{{OrgSynth | first1 = A. C. | last1 = Day | first2 = M. C. | last2 = Whiting | title = Acetone hydrazone | collvol = 6 | collvolpages = 10 | volume = 50 | pages =3 | year = 1970 | prep = cv6p0010}}.</ref><ref name="Ber">{{citation | first1 = H. | last1 = Staudinger | first2 = Alice | last2 = Gaule | title = Vergleich der Stickstoff-Abspaltung bei verschiedenen aliphatischen Diazoverbindungen | journal = Ber. Dtsch. Chem. Ges. | year = 1916 | volume = 49 | issue = 2 | pages = 1897–1918 | doi = 10.1002/cber.19160490245}}.</ref>
 
The direct reaction cannot be used with [[hydrazine]] itself, as the hydrazone that is initially formed will react with a second equivalent of the carbonyl compound to form an [[azine]]. However the azine can be isolated, and then reacted with excess hydrazine to reform the hydrazone.<ref name="acetone">{{OrgSynth | first1 = A. C. | last1 = Day | first2 = M. C. | last2 = Whiting | title = Acetone hydrazone | collvol = 6 | collvolpages = 10 | volume = 50 | pages =3 | year = 1970 | prep = cv6p0010}}.</ref><ref name="Ber">{{citation | first1 = H. | last1 = Staudinger | first2 = Alice | last2 = Gaule | title = Vergleich der Stickstoff-Abspaltung bei verschiedenen aliphatischen Diazoverbindungen | journal = Ber. Dtsch. Chem. Ges. | year = 1916 | volume = 49 | issue = 2 | pages = 1897–1918 | doi = 10.1002/cber.19160490245}}.</ref>

Revision as of 19:57, 19 September 2010

Hydrazones are a functional class of organic compounds formed by the condensation reaction of hydrazine (or, more usually, an N-substituted hydrazine) with an aldehyde or a ketone.[1][2]

Preparation

Substituted hydrazines will react directly with carbonyl compounds to form the corresponding hydrazone.[3] The reaction follows the normal addition–elimination mechanism for reactions at carbonyl carbon, and is acid-catalyzed.

The direct reaction cannot be used with hydrazine itself, as the hydrazone that is initially formed will react with a second equivalent of the carbonyl compound to form an azine. However the azine can be isolated, and then reacted with excess hydrazine to reform the hydrazone.[4][5]

Notes and references

Notes

References

  1. Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995). Pure Appl. Chem. 1995, 67 (8-9), 1307–75 at 1341. DOI: 10.1351/pac199567081307.
  2. hydrazones, <http://goldbook.iupac.org/H02884.html> (accessed 20 September 2010), Compendium of Chemical Terminology Internet edition; International Union of Pure and Applied Chemistry (IUPAC).
  3. Stork, G.; Benaim, J. Monoalkylation of α,β-Unsaturated Ketones via Metalloenamines: 1-butyl-10-methyl-Δ1(9)-2-octalone. Org. Synth. 1977, 57, 69, <http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0242>; Coll. Vol., 6, 242.
  4. Day, A. C.; Whiting, M. C. Acetone hydrazone. Org. Synth. 1970, 50, 3, <http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv6p0010>; Coll. Vol., 6, 10.
  5. Staudinger, H.; Gaule, Alice Vergleich der Stickstoff-Abspaltung bei verschiedenen aliphatischen Diazoverbindungen. Ber. Dtsch. Chem. Ges. 1916, 49 (2), 1897–1918. DOI: 10.1002/cber.19160490245.
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