4,5-Diazafluoren-9-one from the oxidation of 1,10-Phenanthroline by permanganate

Abstract

Abstract4,5-Diazafluoren-9-one is a co-product of the oxidation of 1,lO-phenanthroline with alkaline potassium permanganate along with 2,2'-bipyridyl-3,3'-dicarboxylic acid.4,5-Diazafluoren-9-one (1) has hitherto been a difficultly accessible compound, its only synthesi~l*~ being from the action of aqueous alkali on 1,lO-phenanthroline-5,6-quinone (2) by way of a benzilic acid type rearrangement analogous to the formation of fluorenone from phenanthreneq~inone.~ 1,lO-Phenanthroline-5,6-quinone (2), however, is much less readily prepared than phenanthrenequinone4 and is obtained at best in 15% overall yield by a tedious three-step synthesis from 1,lO-phenanthr~line.~ Consequently, the chemistry of 4,5-diazafluoren-9-one (1) has been neglected apart from studies of its reduction,lg5 its lack of participation in the Schmidt r e a~t i o n ,~ and exploratory chelation experimentse5 We now report a facile one-step synthesis of 4,5-diazafluoren-9-one (1) in about 20% yield by the oxidation of 1,lO-phenanthroline with alkaline permanganate.The oxidation of 1,lO-phenanthroline by aqueous alkaline potassium permanganate to give 2,2'-bipyridyl-3,3'-dicarboxylic acid (3) has been recorded several times, the acid (3) being the only product described in yields varying from

Synthesis and Assessment of CO‐Release Capacity of Manganese Carbonyl Complexes Derived from Rigid α‐Diimine ­Ligands of Varied Complexity

“…The solvents were purified according to the standard procedures [19]. 4,5-Diazafluoren-9-one was synthesized following a reported procedure [20]. Synthesis of [MnBr(CO) 3 (bpy)] ( 1 ) was completed by following a procedure previously reported by us [21].…”

4,5-Diazafluoren-9-one

“…The preparation of L was accomplished by established procedures (Eckhard & Summers, 1973) Crystal data SHELXL93 (Sheldrick, 1993 …”

“…Copies may be obtained through The Managing Editor, International Union of Crystallography, 5 Abbey Square, Chester CH1 2HU, England. Summers, 1973;Henderson, Fronczek & Cherry, 1984;Grigg, Mongkolaussavaratana, Pounds & Sivagnanam, 1990;Baxter, Connor, Wallis, Povey & Powell, 1992). In general, this compound is synthesized by the oxidation of 1,10-phenanthroline by potassium permanganate in alkaline medium.…”

Transfer hydrogenation of aryl ketones with homogeneous ruthenium catalysts containing diazafluorene ligands

“…2‐Propanol was dried over CaH 2 . The ligands 4,5‐diazafluorene‐9‐one, 1‐ H ‐cyclopenta[2,1‐ b :3,4‐ b ']‐dipyridine‐2,5‐dione, 1,5‐dihydro‐2 H ‐cyclopenta[1,2‐ b :5,4‐ b ']dipyridine‐2‐one, 4,5‐diazaflourene, 9,9′‐bis(4,5‐diazafluorenyl), 9,9′‐bis(4,5‐diazafluorenylidene), and N , N ′‐bis(cyclopenta[2,1‐ b :3,4‐ b ']dipyridine‐5‐ylidine) hydrazine were prepared as described previously. 1 H nuclear magnetic resonance (NMR) (400.1 MHz) and 13 C NMR (100.6 MHz) spectra were recorded using a Bruker Avance 400 spectrometer, with δ referenced to external tetramethylsilane.…”