Dibenzofurans oxidation

Considerable progress has also been made with the alternative line of work, the search for a synthetic analgesic as effective as morphine and without its disadvantages. The work of the American Committee has shown that it is possible to produce analgesics with a dibenzofuran or carbazole nucleus in place of the phenanthrene or phcnanthrylene oxide nucleus of morphine and it is stated that synthetic products with analgesic potency equal to that of codeine have been prepared. In the 1938 report moderate analgesic potency was recorded for preparation No. 421, 9-methyl-2-(l-hydroxy-3-diethylamino)-propylcarbazole at 10 mgm. by injection. 

Gesell M, E Hammer, A Mikolasch (2004) Oxidation and ring cleavage of dibenzofuran by the filamentous fungus Paecilomyces lilacinus. Arch Microbiol 182 51-59. 

Hammer E, D Krpowas, A Schafer, M Specht, W Erancke, E Schauer (1998) Isolation and characterization of a dibenzofuran-degrading yeast identification of oxidation and ring clavage products. Appl Environ Microbiol 64 2215-2219. 

Resnick SM, DT Gibson (1996) Regio- and stereospecific oxidation of fluorene, dibenzofuran, and dibenzothiophene by naphthalene dioxygenase from Pseudomonas sp. strain NCIB-4. Appl Environ Microbiol 62 4073-4080. 

Cerniglia CE, JC Morgan, DT Gibson (1979) Bacterial and fungal oxidation of dibenzofuran. Biochem J 180 175-185. 

The enzyme involved in the oxidation of DBTO2 is a 2,3 specific angular dioxygenase, similar to the dibenzofuran 4,4a-dioxygenase enzyme from Sphingomonas... 

The DszC enzyme was able to convert the following compounds other than DBT thioxanthen-9-one, 2,8-dimethyl DBT, 4,6-dimethyl DBT, and 3,4-benzo DBT. Non-organosulfur compounds such as biphenyl, carbazole, and dibenzofuran did not show any activity. This indicates that dszC specifically recognizes sulfur atom [151]. One study specifically examined the DszC enzyme for oxidation of aryl sulfides [179] and reported oxidation of many sulfides including, naphthyl methyl sulfide, phenyl methyl sulfide, and its alkyl derivatives. 

In order to confirm the relative retention times established for DBDPO using only CGC, additional sets of partially brominated diphenyl oxides and dibenzofurans were synthesized using the Fe°/ Br2 procedure. The course of these reactions was followed by both CGC and CGC/MS. As a result, it was possible to simultaneously confirm the previous relative retention time peak assignments as well as to correlate the retention times between the two instruments. Some of the pertinent comparative retention time data obtained from these experiments is summarized in Table I. Upon completion of the individual reactions, a cocktail containing both partially brominated furans and diphenyl oxides was mixed. A typical CGC chromatogram and a CGC/MS total ion chromatogram for this cocktail are shown in Figures 1 and 2, respectively. 

Rentention Time Range, min Diphenyl Oxides Dibenzofurans... 

Figure 1. CGC Chromatogram of Diphenyl Oxide and Dibenzofuran Bromination Reaction Product s Cocktail...

Brominated diphenyl oxides i Brominated dibenzofurans Glass Beads... 

The trimethylsilyloxy (TMSO) group is stable under the coupling conditions in acetonitrile (Table 12, number 6). After oxidative dimerization the TMS-ether can be mildly hydrolyzed (H+ and H2O) to the phenol or converted to a dibenzofuran. 1,2-Dialkoxybenzenes have been trimerized to triphenylenes (Table 5, numbers 7, 8). The reaction product is the triphenylene radical cation, which is reduced to the final product either by zinc powder or in a flow cell consisting of a porous anode and cathode [188]. Anodic trimerization of catechol ketals yields triphenylene ketals, which can function as a platform for receptors, for example, in an artificial caffeine receptor [190]. 

Biological. Dibenzofuran was oxidized by salicylate-induced cells of Pseudomonas sp. strain 9816/11 and isopropyl-P-D-thiogalactopyranoside-induced cells of Escherichia co//JM109 (DE3) (pDTG141) to (li ,25)-ds-l,2-dihydroxy-l,2-dihydrodibenzofuran (60-70% yield) and 3SARj-ds-3,4-dihydroxy-3,4-dihydrodibenzofuran (30-40% yield) (Resnick and Gibson, 1996). 

DIPT, see Isopropyl ether Dipentyl, see Decane Diphenyl, see Biphenyl 1,1 -Diphenyl, see Biphenyl 4,4 -Diphenylenediamine, see Benzidine p,p -Diphenylenediamine, see Benzidine Diphenylenemethane, see Fluorene o-Diphenylenemethane, see Fluorene Diphenylene oxide, see Dibenzofuran Diphenyl ether, see Phenyl ether s/m-Diphenylhydrazine, see 1,2-Diphenylhydrazine lV,A/ -Diphenylhydrazine, see 1,2-Diphenylhydrazine Diphenylnitrosamine, see IV-Nitrosodiphenylamine Diphenyl-lV-nitrosamine, see IV-Nitrosodiphenylamine A,lV-Diphenylnitrosamine, see IV-Nitrosodiphenylamine A,Al-Diphenyl-lV-nitrosamine, see IV-Nitrosodiphenylamine Diphenyl oxide, see Phenyl ether Diphenyltrichloroethane, see p,p -DDT Diphosphoric acid, tetraethyl ester, see Tetraethyl pyrophosphate... 

This review is concerned with the chemistry of dibenzofuran and its derivatives. Dibenzofuran is numbered as in (1) but the system shown in (2) is widespread in the older literature as is the synonym diphenylene oxide. The last comprehensive review on this topic was by Parham and appeared in 1951. The present work covers the period up to Volume 96 of Chemical Abstracts, although the parts of Volume 97 received at the time of writing have been scanned. Reference to literature earlier than 1951 is made only where deemed appropriate. 

Decomposition of 3,4,5,6-tetrachlorobenzene-2-diazo 1-oxide (68, Scheme 17) in chlorobenzene at 130°C presumably involves the ketocarbene 69 and yields some of the dibenzofuran 72 via the 2 -chloro-2-biphenylol 71 because its isomer (70) is also a product. 

Treatment of 2-methoxy-1,4-benzoquinone with hydrogen chloride yields a highly colored compound formulated as the internal quinhydrone 167, which on further reaction with hydrogen chloride yields the dibenzofuran 168. 2-Methoxy-l,4-dihydroxybenzene is oxidized by 1,4-benzoquinone... 

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