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Title: Unexpected reactions of alpha,beta-unsaturated esters with hydrazine hydrate
Authors: Kozlecki, Tomasz ×
Samyn, Celest
Alder, RW
Green, PG #
Issue Date: Jan-2001
Publisher: Royal soc chemistry
Series Title: Journal of the chemical society-perkin transactions 2 issue:2 pages:243-246
Abstract: The reactions of hydrazine hydrate with methyl acrylate and ethyl acrylate do not result in the formation of 1,5-diazabicyclo[3.3.0]octane-2,6-dione 1 at reaction temperatures below 200 degreesC; 1,2-bis(alkoxycarbonylethyl)pyrazolidin-3-one 8, 1-(alkoxycarbonylethyl)pyrazolidin-3-one 6, and 2-(alkoxycarbonylethyl)pyrazolidin-3-one 11 were isolated and identified. At 260-280 degreesC, however, 1 could be isolated in 20-28% yield; formation of 1 could also be observed by spectroscopic measurements when the reaction was carried out above 200 degreesC. It is concluded that the major pathway involves initial Michael addition to give a 1,1-disubstituted hydrazine that cannot yield 1 without undergoing unfavourable retro-Michael reactions. The apparently similar reaction of hydrazine with excess diethyl glutaconate to give 4,8-bis(ethoxycarbonylmethyl)-1,5-diazabicyclo[3.3.0]octane-2,6-dione 2 takes a quite different course. Initial Michael addition gives a 1,2-disubstituted adduct for steric reasons. Although double cyclisation of this adduct to 2 appears straightforward, retro-Michael reaction of the monocyclised adduct is very rapid and competes with the second cyclisation. The reaction of ethyl methacrylate and hydrazine hydrate at 80 degreesC results in a complex reaction mixture, which is transformed into 4-methylpyrazolidin-3-one 13 at 390 degreesC under reduced pressure.
ISSN: 1472-779X
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Molecular Design and Synthesis
Chemistry - miscellaneous
× corresponding author
# (joint) last author

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