Fluorenones fluorenone oximes

Die Reaktion lauft wahrscheinlich iiber das Oxim so wird z. B. aus Kalium-9-ari-nitro-fluoren in 39%iger Ausbeute Fluorenon-oxim1 erhalten. 

The second-order rate constant for the methylation of sodium 9-fluorenone oximate in 33.5% acetonitrile/66.5% t-butyl alcohol solution was found to decrease with increasing concentration of the salt, suggesting an equilibrium (13) between the reactive free anion [109] and the less reactive ion pair [110]... 

Methylation of sodium fluorenone oximate in 33.596 acetonitrile and 66.5% t-butyl alcohol at 25°C in the presence of NaBPh4 or dibenzo-18-crown-6 111] ... 

Phenanthridone has been obtained from both fluorenone and its oxime by Schmidt and Beckmann procedures, respectively. Starting from unsymmetrically substituted fluorenones, mixtures of isomeric phenanthridones are frequently formed. 

Unsuccessful attempts to obtain phenanthridone carboxylic acids by the Beckmann route have also been reported. The oxime of fluorenone-1-carboxylic acid (63) gave only the oxazinone (64) on... 

A mixture of polyphosphoric acid and nitromethane converts fluorenone into phenanthridone at 250°. The reaction probably proceeds via the oxime, which can be isolated when the reaction is carried out at 190°.107 The same conversion can be achieved, though in lower yield, by the action of sodamide on fluorenone in liquid ammonia or (-butylamine. In this reaction biphenyl-2-carboxamide (isolated in 5% yield) is probably a precursor of phenanthridone, since the conversion of the amide to the latter in 40% yield has been demonstrated in a second experiment. The major product of the reaction with fluorenone in liquid ammonia is, not surprisingly, fluorenimine.108... 

Ambident reactivity was shown by oximate anions normally, Oarylation predominated over N-arylation, with ratios of oxime ethers to nitrones ranging from 9 1 (for the benzophenone oxime anion) to 1.7 1 (for the fluorenone oxime anion) [77]. The arylation of two heterocyclic oximes was performed under mild conditions and led mainly to the corresponding oxime ethers which served as good precursors for the generation of unstable aryl fulminates, ArONC [79,80],... 

Seventy grams (1.07 gram atoms) of zinc dust is added in small portions under a reflux condenser to a stirred solution of 40 g. (0.205 mole) of fluorenone oxime (p. 164) in 267 ml. of acetic acid and 13 ml. of water. The rate of addition of the zinc is such as to maintain an even, gentle reflux. The mixture is then refluxed for another hour by the application of heat, and this is followed by the addition of 400 ml. of water. The mixture is filtered and the residue extracted with 200 ml. of hot 5% acetic acid. The solution thus obtained is cooled and filtered, and the filtrate is mixed with an equal volume of concentrated hydrochloric acid and held at 0° for 12 hours. The precipitated amine hydrochloride is removed by filtration and treated with excess ammonium hydroxide solution, and the resulting free base is recrystallized from petroleum ether to give a 90% yield of 9-aminofluorene, m.p. 62-63 . 

A mixture of 8.5 g. (0.047 mole) of fluorenone (p. 163), 6.6 g. (0.95 mole) of hydroxylamine hydrochloride, and 80 ml. of 70% ethanol is refluxed for 3 hours. The ethanol is removed by distillation and the residue treated with excess water. The resulting solid product is removed by filtration and washed thoroughly with water. The solid is recrystallized from ethanol with a charcoal treatment to give an 82% yield of the oxime, melting at 192-193°. 

Fluorene is oxidized to fluorenone in 65-70% yield by refluxing for 3 h with sodium dichromate in acetic acid [622], and 2-methylfluorene is converted into 2-methylfluorenone via its oxime on treatment with amyl nitrite (pentyl nitrite) [452]. The methylene group between two aromatic rings is oxidized in preference to the methyl group because nitrites react only with highly activated methylene groups (equation 177). 

Ketoximes are deprotonated by EGB to the oxime anion, which requires a more negative potential for its reduction. Fluorenone oxime gave for n = 1 unchanged oxime, fluorenone (hydrolysis of fluorenone imine), fluorenone imine, and some 0-butylfluorenone oxime, presumably formed by attach of the oxime anion on TBABF4 [62]. 

Fluorenone oxime was recovered unchanged after being heated with PPA at 120°, but at 180° it was rearranged in almost quantitative yield (Conley )- Conley found PPA to be a superior solvent-catalyst for the Schmidt rearrangement. He added sodium azide in portions to a mixture of a diaryl, aryl-alkyl, symmetrical or unsymmetrical ketones with 15-20 parts of PPA at a temperature in the range 25-75° until evolution of nitrogen ceased, and obtained amides in yields mainly of 80-90%. Doorenbos and Wu studied the conversion of cholestanone and... 

A biological analogue of the above reaction is known. Aryl sulphotransferase isozyme I readily sulphates 9-fluorenone oxime (35) at pH 7-9 to form the sulphate ester, which then rearranges non-enzymically to phenanthridone (equation 19)65. This Beckmann rearrangement accounts for only a part of the transformation of the oxime 35. 

One of the strongest pieces of evidence against the formation of the carbene radical anion comes from an experiment using a nitrogen-15 labelled diazofluorene. The latter was prepared by reacting fluorenone oxime labelled 88% with nitrogen-15 with chloramine (equation 24). 

Fluorenone [486-25-9] M 180.2, m 82.5-83.0 , 85-86 , b 341 /760mm. Crystallise 9-fluorenone from absolute EtOH, MeOH or benzene/pentane. [Ikezawa J Am Chem Soc 108 1589 1986.] Also reciystallise it twice from toluene and sublime it in a vacuum [Saltiel JAm Chem Soc 108 2674 1986], It can be distilled under high vacuum. The oxime has m 195 , 198 (yellow crystals from C6H6 or xylene, Anet et al. Can J Chem 35 180 1957, Wislicenus Waldmuller Chem Ber 41 3335 1908.) [Beilstein 7 H 465, 7 111 2330, 7 IV 1629.]... 

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