On the lead tetraacetate and related oxidations of aromatic ketoximes

Abstract

Fluorenone and benzophenone oxime react in glacial acetic acid with lead tetraacetate to give parent ketones, geminal dinitromethanes, iminyl ketal derivatives (9,9-difluorenylideniminoxylfluorene and l,l-bis(diphenylmethylideniminoxyl)-diphenylmethane), and minor amounts of oxime 0-acetate. Benzophenonenitrimine is also formed but only in the absence of oxygen. Side reactions due to nitricoxide, oxygen, and nitrogen dioxide take place. Separate studies with these oxidizing agents have therefore been conducted. The lead tetraacetate oxidation of these oximes in methylene chloride (or any other so1vent)is complete with a half-mole equivalent of lead tetraacetate, is insensitive to molecular oxygen, and affords mainly parent ketone and ketazinemonoxides. N o ketazine-bis-N-oxides, obtained from the ferricyanide oxidation of these oximes, are formed. The model oximes, benzil anti-monoxime, xanthone oxime, and indanone oxime have been studied in the light of these observations. Mechanisms involving iminoxyl radicals have been postulated for all reactions studied.

Energetic Di- and Trinitromethylpyridines: Synthesis and Characterization

“…N 2 O 4 was added into a solution of pyridine-2-carboxaldoxime at room temperature and the purification of products was carried out by column chromatography in a Biotage Isolera One apparatus. The reaction mechanism has been given in the literature earlier ( Scheme 2 ) [ 25 , 31 ]. The preparation of bis(trinitromethyl)-substituted pyridine was somewhat more challenging.…”