117341-57-8Relevant articles and documents
ORGANIC COMPOUNDS
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Page/Page column 31, (2009/12/02)
The invention relates to organic compounds which have interesting pharmaceutical properties. In particular, the compounds are useful in the treatment and/or prevention of infections such as those caused by Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, Plasmodium ovale, Trypanosoma cruzi and parasites of the Leishmania genus such as, for example, Leishmania donovani. The invention also relates to pharmaceutical compositions containing the compounds, as well as processes for their preparation.
Synthesis of 6-ethoxy-6H-1,2-oxazines by hetero Diels-Alder reaction of 1-bromo-2-ethoxyethene with α-nitroso alkenes
Homann, Kai,Angermann, Joerg,Collas, Markus,Zimmer, Reinhold,Reissig, Hans-Ulrich
experimental part, p. 649 - 655 (2011/10/09)
A variety of 6H-1,2-oxazines 10 could efficiently be prepared by hetero Diels-Alder reaction of α-nitroso alkenes 2 with 1-bromo-2-ethoxyethene (8) and consecutive elimination of HBr by DBU. Heterodienes 2 were generated in situ from α-halogen oximes 6. Primary cycloadducts 9 were isolated in singular cases, however, an attempt to substitute bromide in 9e by an azido group gave the desired compound 11 only as minor component together with elimation product 10e. 6H-1,2-oxazines 10 are valuable precursors for addition reactions which open new synthetic possibilities.
Efficient Synthesis of Trifluoromethyl-Substituted 5,6-Dihydro-4H-1,2-oxazines by the Hetero-Diels-Alder Reaction of 1,1,1-Trifluoro-2-nitroso-2-propene and Electron-Rich Olefins
Zimmer, Reinhold,Reissig, Hans-Ulrich
, p. 339 - 347 (2007/10/02)
1,1,1-Trifluoro-2-nitroso-2-propene (1) was generated in situ by treatment of the α-bromo oxime 5 with base.Moderate to excellent yields of the 3-trifluoromethyl-substituted 1,2-oxazines 17-27 were obtained from the reaction of 1 and the silyl enol ethers 6-16, respectively.Other dienophiles, i.e., allyltrimethylsilane, cyclopentadiene, furan, and dihydropyran, upon reaction with 1 provided the cycloadducts 31-34, respectively, in good yield.The results demonstrated that 1 is probably the most reactive heterodiene that has so far been employed in this type of Diels-Alder reaction (i.e., Diels-Alder reaction with inverse electron demand).The mechanism of the reaction and diastereoselectivity of the cycloadditions are discussed.The reaction of 1 with indole and acetyl acetone afforded the oxime 38 and a mixture of the isomers 40-42, respectively.Also, ring opening and other transformations of the trifluoromethyl-substituted 1,2-oxazines were effected.Acid-induced desilylation of the silylated 1,2-oxazines provided oximes like 46 and 48 or 6-hydroxy-1,2-oxazines like 47.Treatment of the 1,2-oxazines with Mo(CO)6 in the presence of trifluoroacetic acid produced 2-trifluoromethyl-substituted pyrroles (e.g., 18 -> 50).The reduction of the 1,2-oxazines afforded either γ-hydroxy oximes (e.g., 19 -> 51) or amino alcohols (e.g., 32 -> 52, 31 -> 55).The reduction of the indole derivative 38 by LiAlH4 provided the trifluoromethyl-substituted tryptamine 56.The results of these explorative studies demonstrated that readily available trifluoromethyl-substituted 1,2-oxazines could be efficiently converted into other compounds that bear a trifluoromethyl group.