Revisiting the three component synthesis of isoxazolo[5,4-b]pyridines, 4-aryl-3,7,7-trimethyl-isoxazolo[5,4-b]quinolin-5(6H)-ones and related heterocycles
Journal article
Lingham, Anthony R., Hawley, John A., Greaves, Tamar, Jackson, Neale, Antolasic, Frank and Hugel, Helmut M.. (2016). Revisiting the three component synthesis of isoxazolo[5,4-b]pyridines, 4-aryl-3,7,7-trimethyl-isoxazolo[5,4-b]quinolin-5(6H)-ones and related heterocycles. Polyhedron. 120, pp. 175 - 179. https://doi.org/10.1016/j.poly.2016.09.011
Authors | Lingham, Anthony R., Hawley, John A., Greaves, Tamar, Jackson, Neale, Antolasic, Frank and Hugel, Helmut M. |
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Abstract | The one-step three-component microwave assisted synthesis between aromatic aldehydes with tetronic acid or indan-1,3-dione readily formed the Knoevenagel adducts that underwent addition of 3-methylisoxazol-5-amine 1 to form the isoxazolo[5,4-b]pyridine products 8[a,b,d,e,g] in 67–90% yield. The multicomponent reaction using dimedone formed the respective addition products 4-aryl-3,7,7-trimethyl-isoxazolo[5,4-b]quinolin-5(6H)-ones 8[c,f,h] (36–79%). In contrast, the sonication of an aryl aldehyde and dimedone with an equivalent amount of 2-hydroxyammonium formate exclusively generated the Knoevenagel adduct 4c via hydro-4c. When microwaved either with 3-amino-5-methylisoxazole 1 or 3,4,5-trimethoxyaniline 14 in ethanoic acid–ethylacetate (1:1), tetrahydroacridones 15[a,b] formed in high yields (88–92%). Importantly, this two-step reaction sequence generates highly reproducible and pure products. |
Keywords | multicomponent microwave synthesis; knoevenagel; isoxazolopyridines; isoxazoloquinolinones; tetrahydroacridones |
Year | 2016 |
Journal | Polyhedron |
Journal citation | 120, pp. 175 - 179 |
Publisher | Elsevier Ltd |
ISSN | 0277-5387 |
Digital Object Identifier (DOI) | https://doi.org/10.1016/j.poly.2016.09.011 |
Scopus EID | 2-s2.0-84997769381 |
Page range | 175 - 179 |
Publisher's version | File Access Level Controlled |
Place of publication | United Kingdom |
https://acuresearchbank.acu.edu.au/item/8v26q/revisiting-the-three-component-synthesis-of-isoxazolo-5-4-b-pyridines-4-aryl-3-7-7-trimethyl-isoxazolo-5-4-b-quinolin-5-6h-ones-and-related-heterocycles
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