The conventional methods employed for the synthesis of substituted isoxazole-5(4H)ones, include cyclization of O-propioloyl oximes , reaction of ethyl acetoacetate
and hydroxylamine hydrochloride followed by the Knoevenagel condensation with aromatic aldehydes in two steps [28-30], condensation of substituted benzaldoximes and 1,3-dicarbonyl compounds , and reaction of [beta]-oxoesters with hydroxylamine and sodium hydroxide with subsequent addition of aqueous HCl followed by heating .
a-Aminoxylated ethyl acetoacetate
and indole was selected as model substrates to investigate the tandem reaction.
In the initial experiments, the multicomponent reaction of benzyl alcohol, ethyl acetoacetate
, and ammonium acetate was selected as a model reaction (Scheme 2).
When heating was completed, ethyl acetoacetate
(0.3 ml) and urea (0.09 g, 1.5 mmol) were added and mixture was again refluxed.
ABSTRACT: A copper metal complex has been synthesized by condensation and cyclization methodology.The ligand was synthesized by MCR (multi component reaction) of ortho toluidine, ethyl acetoacetate
and triethyl orthoformate and the condensed product was further cyclized in dowtherm A.
, methyl acetoacetate, dimethyl acetoacetamide, monomethyl aceto-acetamide, and acetoacetanilide are low-color copromoters for room-temperature cure of unsaturated polyesters.
In this experiment we used benzene as a solvent; p-toluenesulfonic acid (TsOH), which has strong acidity but low nucleophilicity, as a catalyst; and acetylacetone, ethyl acetoacetate
, and diethyl malonate as nucleophiles.
Elaborating on the procedure of the research, Shaneghi reiterated, "First, we mixed ethanol and ethyl acetoacetate
together at the room temperature.
W e synthesized 5,6-dehydrokawain (1) and yangonin (4) via three steps from the dianion of ethyl acetoacetate
achieving a good yield and determined their conformations by high resolution NMR and x-ray crystallographic analysis.
Several dilithiated beta-ketoesters, such as ethyl acetoacetate
, and beta-diketones, such as 1-benzoylacetone, were condensed with polylithiated methyl 2-(aminoulfonyl)-benzoate to give C-acylated intermediates that were not isolated but cyclized directly to the 3-substiuted 1,2-benzisothiazole 1,1-dioxides.
The reaction of isatin 1(1 mmol), hydrazine hydrate 2 (2 mmol) and ethyl acetoacetate
3 (2 mmol) was investigated as a model reaction.
1.4 moles and 3.5 mole of glacial acetic acid were taken in three naked round bottom flask fitted with thermometer, reflux condenser and mechanical stirrer and cooled in ice bath at 0[degrees]C and a solution of 95 % sodium nitrite was added over a period of one hour and temperature being kept between 5[degrees]C to 10[degrees]C.