4-Trifluoroacetyl-2-phenyloxazol-5-one: Versatile Template for Synthesis of Trifluoromethyl-Substituted Heterocycles
摘要:
4-Trifluoroacetyl-2-phenyloxazol-5-one (1) is a versatile template for the synthesis of various trifluoromethyl-substituted heterocycles. Cyclocondesation of 1 with hydroxylamine and hydrazine afforded isoxazole and pyrazole, respectively. Another key protocol involves nucleophilic ring opening of 1 with H2O or MeOH to give alpha-amido trifluoromethyl ketones which are transformed into trifluoromethyl-substituted thiazoles, oxazoles, imidazoles, pyrazoles, and pyrimidines.
Synthesis of fluorinated α-amino ketones part I: α-benzamidoalkyl mono- di- and trifluoromethyl ketones
作者:Michael Kolb、Jacqueline Barth、Bernhard Neises
DOI:10.1016/s0040-4039(00)84319-1
日期:1986.1
2-Phenyl-5(4H)-oxazolones, obtained from α-amino acids, are reacted with di- and trifluoro acetic anhydride by a modified Dakin-West procedure to yield in a one-pot reaction α-benzamidoalkyl-di- and trifluoromethyl ketones in good yields. The monofluoromethyl analogues were also prepared from α-amino acids, however the use of the highly toxic fluoroacetic anhydride was avoided. The key step is the
Reaction of (Trifluoromethyl)trimethylsilane with Oxazolidin-5-ones: Synthesis of Peptidic and Nonpeptidic Trifluoromethyl Ketones
作者:Magnus W. Walter、Robert M. Adlington、Jack E. Baldwin、Christopher J. Schofield
DOI:10.1021/jo980443+
日期:1998.7.1
(Trifluoromethyl)trimethylsilane (TMS-CF3, the Ruppert Reagent) reacts with a variety of amino acid derived N-substituted oxazolidin-5-ones in excellent yields. Mild acid hydrolysis of adducts with electron-releasing substituents at C-2 affords N-substituted cx-amino trifluoromethyl ketones (TFMKs). N-CBZ-protected alpha-amino TFMKs are converted into hitherto unreported hydrochloride salts of alpha-amino TFMKs by hydrogenolysis. Coupling with aminoacid fluorides gives access to peptidic TFMKs which are of utility as protease inhibitors.
344. Studies of trifluoroacetic acid. Part XVIII. Reaction of N-aroylglycines with perfluoro-carboxylic anhydrides
作者:E. J. Bourne、J. Burdon、V. C. R. McLoughlin、J. C. Tatlow