Benzo c fluorene

Ohwada extends his theory, unsymmetrization of n orbitals, to Orbital Phase Environment including the secondary orbital interaction (Chapter Orbital Phase Environments and Stereoselectivities by Ohwada in this volume). The reactions between the cyclopentadienes bearing spiro conjugation with benzofluorene systems with maleic anhydride exemplified the importance of the phase environment. The reactions proceed avoiding the out-of-phase interaction between dienophile LUMO and the HOMO at the aromatic rings. The diene 34 with benzo[b]fluorene favored syn addition with respect to the naphtalene ring, whereas the diene 35 with benzo[c]fluorene showed the reverse anti preference (Scheme 22) [28]. 

Very recently, a series of novel carbocations and carboxonium ions were generated from 77/-benzo[c]fluorene (80), 1 l//-benzo[Z)]fiuorene (81), ll//-benzo[a]fluorene (82), 2-methoxy- (83), 7-methoxy- (84), and 9-methoxy-l l//-benzo[u]fluorene (85), 7//-dibenzo-[c,g]fluorene (86), 137/-dibenzo[u,g]fluorene (87), 2-methoxy-13//-dibenzo [u,g]fluorene (88), and 5,6-dihydro-13//-dibenzo[u,g]fluorene (89) (Fig. 30). Charge delocalization modes in the resulting carbocations were derived based on experimental and/or computed (GIAO-DFT) A8 C NMR values and via the NPA-deiived changes in charges (A ). 

Cyclopropanation of the C=C bond of an allylic halide as in the cyclopropane 15 greatly suppresses photoreactivity, which is restored by introduction of a vinyl group at the 2-position of the cyclopropyl group, as in 16 (equation 27)134. The shift in UV-absorption maxima of 15 and 16 indicates the presence of electronic interactions of the vinyl and bro-momethyl moieties through the cyclopropane ring in 16. A similar arrangement of chro-mophoric moieties is present in compound 17, which on direct irradiation in acetic acid yields benzo[c]fluorene as sole product (equation 28)135. 

Preparation of 3-methoxy-6-(2- methyl-[2-(3-methoxy-7-oxo-7H-5,9-diaza-benzo[c]fluoren-6-ylamino)-ethyl]-amino -ethylamino)-5,9-diaza-benzo[c]fluoren-7-one... 

A mixture consisting of 6-chloro-3-methoxy-5,9-diaza-benzo[c]fluoren-7-one (21 mg), A-methyl-2,2 -diaminodiethylamine (3.3 mg), and K2C03 (10 mg) was suspended in 0.5 ml DMF and stirred 13 hours at 90°C, then concentrated. The residue was purified by chromatography on silica gel using CH2Cl2/methyl alcohol,... 

The preparation of the Step 1 co-reagent, 6-chloro-3-methoxy-5,9-diaza-benzo[c]fluoren-7-one, (II), by Aoyama (1) is illustrated in Eq. 2. The effectiveness of these derivatives, (III), against HCT116 cells is provided in Table 2. 

In a two-year toxicological study (Culp et al., 2000), the incidences of tumours and DNA adducts in mice fed either coal tar or pure benzo[a] pyrene were examined. Benzo[a]pyrene formed adducts readily with DNA and appeared to be responsible for forestomach tumours, like those induced by ingestion of coal tar, but not for lung tumours. Other mice that were fed coal tar (Koganti et al., 2001) had DNA adducts with benzo[u]pyrene, benzo[c]fluorene and benzo[Z)]fluoranthene in the lungs, but those fed coal tar-contaminated soil had only the adducts with benzo[c]fluorene and benzo[ ]fluoranthene. Although benzo[u]pyrene activation has been studied extensively, little is known about the activation mechanisms of benzofluor-enes and benzofluoranthenes. 

C17H12 7H-benzo(c)fluorene 205-12-9 680.95 61.514 2 30060 C17H18F3N N-benzyl-a-methyj-m-trifluoromethylphenethyr 62064-66-8 451.15 39.211 1,2... 

Melkova, Z. (1984). Utilization of the Index of Molecular Connectivity in the Study of Antitumor Activity of a Group of Benzo(c)fluorene Derivatives. Cesk.Farm., 33,107. 

Koganti A, Singh R, Rozett K, et al. 2000. 7H-benzo[c]fluorene a major DNA adduct-forming component of coal tar. Carcinogenesis 21(8) 1601-1609. 

Benzo[/3]fluorene, methyl-11/-/-Benzo[t)]fluorene, 9-methyl-Benzo[c]fluorene, methyl-7/-/-Benzo[c]fluorene... 

The reactivity of the bicyclic VDCP was also investigated in presence of an aldehyde partner (Scheme 8.10) [24]. Its treatment by iron trichloride and trimethylsilyl chloride in presence of p-nitrobenzaldehyde triggered the formation of the corresponding benzo[c]fluorene derivative in 17% yield, along with a furan derivative in 26%. On the other hand, when the reaction was performed with BF3-Et20, a tetrahydrofuran derivative was formed in good yield, which further converted into furan in almost quantitative yield upon exposure to BF3-Et20 and TMSCl. Of note,... 

In addition, the Joint FAO/WHO Experts Committee on Food Additives 0ECFA) identified the PAH compound benzo[c]fluorene as to be monitored as well (Figure 4.101) (JECFA, 2005). 

Butyryl-2-(3-chloropropyl)-1 -(methoxycarbonyl)-1,2-dihydropyridine 7-Methyl-7//-benzo[c]fluorene-7-carboxylic acid... 

---