The reaction of 3-ethoxycarbonyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydroxylamines has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of hydroxylamine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring-opening and ring-closure with enlargement, leads to high yield and in very mild experimental conditions to the formation of 5-hydroxyamino-3-perfluoroalkyl-6H-1,2,4-oxadiazin-6-ones, one of these presenting water gelation ability. In turn, reactions with N-methylhydroxylamine lead the exclusive formation of 4-perfluoroacylamino-2-methyl-2H-1,2,5-oxadiazol-3-ones through the well known Boulton-Katritzky rearrangement. (C) 2009 Elsevier Ltd. All rights reserved.
Piccionello, A.P., Pace, A., Buscemi, S., Vivona, N., Giorgi, G. (2009). Synthesis of Fluorinated 1,2,4-Oxadiazin-6-ones Through ANRORC Rearrangement of 1,2,4-Oxadiazoles. TETRAHEDRON LETTERS, 50(13), 1472-1474 [10.1016/j.tetlet.2009.01.071].
Synthesis of Fluorinated 1,2,4-Oxadiazin-6-ones Through ANRORC Rearrangement of 1,2,4-Oxadiazoles
Giorgi, Gianluca
2009-01-01
Abstract
The reaction of 3-ethoxycarbonyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydroxylamines has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of hydroxylamine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring-opening and ring-closure with enlargement, leads to high yield and in very mild experimental conditions to the formation of 5-hydroxyamino-3-perfluoroalkyl-6H-1,2,4-oxadiazin-6-ones, one of these presenting water gelation ability. In turn, reactions with N-methylhydroxylamine lead the exclusive formation of 4-perfluoroacylamino-2-methyl-2H-1,2,5-oxadiazol-3-ones through the well known Boulton-Katritzky rearrangement. (C) 2009 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11365/10119
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