161126-53-0Relevant articles and documents
A New Entry to Isoxazolo[4,5-d]pyridazin-4(5H) [and 7(6H)]-ones from Functionalized Vinyl Sulfoxides
Ruano, J. L. Garcia,Bercial, F.,Fraile, A.,Martin, M. Rosario
, p. 73 - 76 (2007/10/03)
Isoxazolo[4,5-d]pyridazin-4(5H) [and 7(6H)]-ones can be respectively synthesized in a one-pot two-step synthetic sequence from 4 or 3-arylsulfinyl-5-alkoxyfuran-2(5H)-ones, involving their reactions with nitrile oxides and subsequent reflux with hydrazine hydrate into a 4:3 mixture of water/acetic acid. The 1,3-dipolar reaction takes place with complete regioselectivity, which is controlled by the position of the sulfinyl group at the dipolarophile, yielding, after desulfinylation and subsequent opening of the lactone ring, the two possible regioisomeric 3-substituted isoxazoles bearing formyl and carboxylic acid moieties at C-4 and C-5. These compounds, as well as their methyl esters, can be independently transformed into the corresponding isoxazolopyridazinones in high yields by reaction with hydrazine hydrate.
SYNTHESIS OF ISOXAZOLES BEARING METHOXYCARBONYL AND FORMYL GROUPS BY 1,3-DIPOLAR CYCLOADDITION OF NITRILE OXIDES TO OLEFINIC AND ACETYLENIC DIPOLAROPHILES
Farina, Francisco,Fraile, M. Teresa,Martin, M. Rosario,Martin, M. Victoria,Guerenu, Ana Martinez de
, p. 285 - 292 (2007/10/02)
The 1,3-dipolar cycloaddition of benzo-, bromoformo- and acetonitrile oxides to enamino ester (1) and acetylenic esters (2,3) afforded functionalized isoxazoles in moderate to good yields.Cycloadditions with the enamino ester (1) gave the corresponding me
