4H-Cyclopenta

Nothing is known about analogous condensation reactions of o-alkyl-aminobenzaldehydes with a,/3-unsaturated cyclopentenones leading to pseudoazulenes 39, 43, or 46. Acid-catalyzed reaction of o-aminobenz-aldehyde with cyclopentenones produces 3//-cyclopenta[b] quinolines that can be transformed to 4H-cyclopenta[b]quinolines by quaternization and subsequent deprotonation.51... 

The mass spectra of benzofused pseudoazulenes 65 and 80 -83 show the mass ion as the base peak, and intense peaks are observed that correspond to the doubly charged molecular ion. The authors197 have attributed this fact to the aromaticity of these systems. This conclusion, however, cannot be drawn for all pseudoazulenes since the relative intensity of the mass ion for 26b is only 5.5%,55 for 4-methyl-4H-cyclopenta[b]quinoline 64%, 14 for 5-methyl-5/f-cyclopenta[c]quinoline7.0%,123andfor2-phenacyl-9-benzoyl-2H-indeno[2,1-fo] pyridine 18%.105... 

The polymers of 4H-cyclopenta[2,l-b 3,4-//Jdi thiophene derivatives showed absorptions in the range 560-590 nm [03MM2705]. Some monomers are based on the nonaromatic (12 n electrons) 4H-cyclopenta[2,l-fr 3,4-l/]dithiophen-4-yl cation 580a (X = CH+) model which was expected to display a reduced HOMO-LUMO separation, compared to related aromatic fused systems (i.e., 580, X = S, O, NF1) (91JCS(CC)752). Polymers of 580 (X = S) showed absorption at 480 nm. Poly(dithieno[3,4-b 3, 4 -4J thiophene) showed an absorption at 590-610 nm (89SM(28)C507 97MI23). 

Fifty-four PAHs have been identified at one or more NPL hazardous waste sites. These 54 are acenaphthene, acenaphthylene, 2-acetoaminofluorene, anthracene, 9,10-anthracenedione, benz[a]anthracene, benzo[a]pyrene, benzo[e]pyrene, benzo[a]fluoranthene, benzo[b]fluoranthene, benzo[b]fluorene, benzofluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene. benzo[g,h,i]fluoranthene, benzoperylene, benzo[g,h,i]perylene, benzophenanthrene, benzopyrene, benzothiophene, benzo[b]thiophene, chrysene, 4H-cyclopenta[d,e,f]phenanthrene, dibenz[a,j]anthracene, dibenz[a,h]anthracene, 7,12- dimethylbenz[a]anthracene,... 

Piotrowak and co-workers [65b] reported zwitterionic nature of the singlet excited state of biphenanthrylidene (bi-4H-cyclopenta[def]phenanthren-4-ylid-ine abbreviated as BPH) is an analog of TPE. The illustration is given in Scheme... 

Hiqgegen erfolgt die Addition von Alkoholen an 2-Amino-l,3-thiazole an die 4-Position. Die Reaktion versagt bei hoheren Homologen von 2-Amino-5,6-dihydro-4H-[Pg.349]

Amin, S., Desai, D., Dai, W., Harvey, R.G., and Hecht, S.S. (1995) Tumori-genicity in newborn mice of fjord region and other sterically hindered diol epoxides of benzo[g]chrysene, dibenzo[a,l]pyrene (dibenzo[de/p] chrysene), 4H -cyclopenta[de/]chrysene and fluoranthene. Carcinogenesis, 16, 2813-2817. 

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