215675-46-0Relevant academic research and scientific papers
First Examples of Reactions of Azole N-Oxides with Thioketones: A Novel Type of Sulfur-Transfer Reaction
Mloston, Grzegorz,Gendek, Tomasz,Heimgartner, Heinz
, p. 1585 - 1595 (1998)
The reactions of 1,4,5-trisubstituted imidazole 3-oxides 1a-k with cyclobutanethiones 5a,b in CHCl3 at room temperature give imidazole-2(3H)-thiones 9a-k in high yield. The second product formed in this reaction is 2,2,4,4-tetramethylcyclobutane-1,3-dione (6a; Scheme 2). Similar reactions occur with 1 and adamantanethione (5c) as thiocarbonyl compound, as well as with 1,2,4-triazole-4-oxide derivative 10 and 5a (Scheme 3). A reaction mechanism by a two-step formation of the formal cycloadduct of type 7 via zwitterion 16 is proposed in Scheme 5. Spontaneous decomposition of 7 yields the products of this novel sulfur-transfer reaction. The starting imidazole 3-oxides are conveniently prepared by heating a mixture of 1,3,5-trisubstituted hexahydro-1,3,5-triazines 3 and α-(hydroxyimino) ketones 2 in EtOH (cf. Scheme 1). As demonstrated in the case of 9d, a 'one-pot' procedure allows the preparation of 9 without isolation of the imidazole 3-oxides 1. The reaction of 1c with thioketene 12 leads to a mixture of four products (Scheme 4). The minor products, 9c and the ketene 15, result from an analogous sulfur-transfer reaction (Path a in Scheme 5), whereas the parent imidazole 14 and thiiranone 13 are the products of an oxygen-transfer reaction (Path b in Scheme 5).
First synthesis of the N(1)-bulky substituted imidazole 3-oxides and their complexation with hexafluoroacetone hydrate
Mloston, Grzegorz,Jasinski, Marcin
body text, p. 162 - 175 (2011/06/19)
Synthesis of new 2-unsubstituted imidazole 3-oxides bearing bulky substituents at the N(1) atom, based on the condensation of appropriate alkylamines, formaldehyde, and corresponding a-(hydroxyimino)ketone, is described. Treatment of imidazole 3-oxides with hexafluoroacetone hydrate (HFAH) yields crystalline 1:1 complexes in nearly quantitative yields. Heating of isolated complexes possessing phenyl ring at the C(4) atom of imidazole ring, results in their isomerization into imidazol-2-ones in fair yields. The formation of analogous complexes of HFAH with other azole N-oxides is also described. ARKAT-USA, Inc.
