Benzo fluorenones

Benzofluorenone undergoes the Schmidt reaction in trichloroacetic acid to give an approximately equimolecular mixture of 2,3- and 8,9-benzophenanthridone.105 Under similar conditions 3,4-benzo-fluorenone (65) forms a mixture of 1,2- (66) and 9,10-benzophenan-thridone (67) in which the former predominates.113 The failure of... 

Benzo-fluorenon-oarboiU9aure.(l), Allooh eoketon-carboiuaure 10, 735,... 

TCBTs are relatively persistent and non-flammable (and therefore useful in hydraulic oils). Pyrolysis in a closed system for two days in the presence of hydrogen peroxide at 300 °C produced as main components chlorinated benzo-phenones, fluorenes, fluorenones, xanthenes, and xanthones. Polychlorodiben-zofurans (PCDF) and polychlorodibenzo-p-dioxins (PCDD) were formed in much lower concentrations than from PCB product Pyralene T1 under identical conditions [84]. In pyrolysis at 450-700 °C with excess oxygen TCBTs produce more PCDFs and PCDDs. In parallel with the behavior of PCBs, PCDFs are formed in significantly higher amounts than PCDDs from PCBTs [86],... 

The ground state structure of the photochemical reaction site of benzo-phenones has been examined by the MO method and IR absorption spectrometry, and comparisons made with fluorenone. ... 

In water, ozonation is generally slower and less efficient than chlorination in degrading PAHs (Neff 1979). Reaction pathways for ozonation of some PAHs include benz[a]anthracene to 7,12-quinone benzo[a]pyrene to 3,6-, 1,6-, and 4.5-diones and fluorene to fluorenone (NAS 1972). 

In detail, several alkylated and nonalkylated polycyclic aromatic compounds (PAHs) were detected and dominated by acenaphthene with a maximum concentration of 24 pg/L in sample B. Total concentrations of methyl- and dimethylnaphthalenes reached 5.1 pg/L and 24 pg/L, respectively. Tricyclic aromatic compounds and oxygenated PAH species were detected comprising e.g. phenanthrene, 9H-fluorenone and acenaphthenone. Methylated and dimethylated benzo(b)thiophenes as well as dibenzothiophene were also present. 

LeBel and Whang182 obtained a tetrahydro-l,3-oxazine (66) and an open-chain amide by irradiating (2537 A) the fused isoxazolidine 39b. The yield of 66 is increased if the reaction is photosensitized with benzo-phenone or fluorenone. 

Intramolecular or partially intramolecular cycloaddition reactions are extremely useful tools in the synthesis of polycyclic molecules, since they can allow the construction of several rings in a single step. Preliminary studies indicate that this general principle also holds for partially intramolecular versions of the palladium-catalyzed cocycloaddition of arynes and alkynes. For example, benzo[fc]fluorenones 144a-d, which constitute the polycyclic skeleton of the kinamycin family of antitumour antibiotics, can be obtained by [2+2+2] cy-... 

FIGURE 7.10 TIC of EV-Py-GC/MS analysis of polluted soil sample. The upper trace represents a part of the TIC magnified eight times. The number in the mass chromatograms represents the m/z values indicative of the following classes of compounds 104, 118, 132 (Cq to Cj styrenes) 116, 130 (Cq to Cj indenes) 128, 142, 156, 170 (Cq to C3 naphthalenes) 134, 148, 162 (Co to Ci benzo[b]thiophenes) 154 (biphenyl and acenaphthene) 168, 182, 196 (C[ to Cj byphenyls and Cq to Cj dibenzofurans) 166, 180 (Cq to Cj fluorenes and 9-fluorenone) 184 (dibenzothiophene) 202 (fluoranthene and pyrene) 228 (benzo[c]phenan-threne, benz[a] anthracene, chrysene, and triphenylene) and 252 (benzo[e]pyrene and benzo[a]pyrene). The x axes of the mass chromatograms correspond exactly with the appropriate parts of the TIC x axis directly above them (e.g., the major peak in the mass chromatogram of m/z =168 corresponds with peak 41 in the total ion cnrrent profile). (From de Leeuw, J.W. et al.. Anal. Chem., 58 1852 (1986). With permission.)... 

The catalyst Pd2(dba)3 also successfully promotes the [2+2+2] cocyclotrimeriza-tion of arynes with suitably functionalized benzodiynes, affording benzo[fe]fluorenones in moderate yields (Equation 12.54) [120]. The best result was achieved when the electron-deficient diyne 222 was employed, when the corresponding benzo[fe]fluorenone 223 was obtained in 54% yield. 

Pyrones, benzo[a]fluorenones s. 16, 821 4-Pyrone ring synthesis and degradation... 

Patra et al. described the regiospecific synthesis of benz[a]anthracene-5,6-dione 9 and their efficient conversion to benzo[h]fluorenones 11 through the carboxylic acid 10. The transformation of 9 to 10 has been effected by benzilic acid rearrangement employing the method of Toda et using powdered KOH in dioxane. Several other conditions such as NaOH in water, KOH in a mixture of ethanol and water, KOH in a mixture of dioxane and water and NaOEt in ethanol did not give satisfactory results. 

Benzoyloxy-fIaorenon 9,153. 3 BenzoyIoxy.fluorenon 9, 153. 3 Benzoyl-7.8.benzo.cnmarin 17 II 513. 2.Benzoy] Xanthon 17, 544. 

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