6- phenanthridines

Derived from either a pyrrolo[<7( ]phenanthridine or a [5,10/ ]ethanophenanthridine. 

Azonia substitution at a naphthalene bridgehead position gives the quinolizinium ion (16). Oxonia substitution, elsewhere, forms the 1- and 2-benzopyrylium ions (17) and (18). The two most well-known monoaza systems with three aromatie fused rings are aeridine (19), derived structurally from anthraeene, and phenanthridine (20), an azaphenanthrene. The better-known diaza systems inelude phenazine (21) and 1,10-phenanthroline (22), while systems with three linearly fused pyridine rings are ealled anthyridines, e.g. the 1,9,10-isomer (23). 

X-ray crystal structure, 6, 516 Benzophenanthridines synthesis from anils, 2, 416 Benzophenanthridines, tetrahydro-synthesis, 2, 469 Benzo[c]phenanthridines synthesis, 2, 414 from aryl isocyanides, 2, 411 from benzynes, 2, 432 Benzo[i]phenanthridines synthesis, 2, 414 Benzophenanthridinones... 

Phenanthridine-6-carboxylic acids synthesis, 2, 415 Phenanthridines amination, 2, 236 bromination, 2, 320 hydrogenation, 2, 328 nitration, 2, 319 nomenclature, 2, 5 5-oxides... 

Protoporphyrin-IX, N-methyl-, 4, 396 Protoporphyrins, 4, 382 photooxygenation, 4, 402 Prototropic tautomerism polyheteroatom six-membered rings, 3, 1055 Prozapine properties, 7, 545 Pschorr reaction carbolines from, 4, 523 dibenzazepines from, 7, 533 dibenzothiophenes from, 4, 107 phenanthridines from, 2, 433 Pseudilin, pentabromo-synthesis, 1, 449 Pseudoazulene synthesis, 4, 526 Pseudobases in synthesis reviews, 1, 62 Pseudocyanines, 2, 331 Pseudothiohydantoin synthesis, 6, 296 Pseudouracil structure, 3, 68 Pseudoyangonin IR spectra, 3, 596 Pseudoyohimbine synthesis, 2, 271 Psicofuranine biological activity, 5, 603 as pharmaceutical, 1, 153, 160... 

Benzoquinoline (phenanthridine) [229-87-8] M 179.2, m 108-109 , b 350 , pK 4.61. Chromatographed on activated alumina from benzene soln, with diethyl ether as eluent. Evapn of ether gave crystalline material which was freed from residual solvent under vacuum, then further purified by fractional crystn under N2, from its melt. Sublimes in vacuo. See also p. 324. 

The former passes into the second on further oxidation with hydrogen peroxide, indicating that it is an a-keto-carboxylic acid. Acid (b) loses carbon dioxide on fusion and gives a neutral substance, CjaHj OgN, m.p. 238°, which was shown to be 6 7-methylenedioxy-A-methylphenanthri-done (I), by comparison with a synthetic specimen. The position of the carboxyl group in (b) could not be determined by synthetic methods but is probably at since dihydrolycorineanhydromethine, Cl 7 7 2 ) m.p. 87-5° [picrate, m.p. 174° (dec.) methiodide, m.p. 236° (dec.)] on distillation with zinc dust yields a mixture of phenanthridine, 1-methyl-phenanthridine and 6 7-methylenedioxyphenanthridine, m.p. 142° [picrate, m.p. 257° (dec.)], the identity of the two latter being established by comparison with the synthetic products. These results indicate for lycorineanhydromethine formula (II). 

Petrocapnos spp., alkaloids, 173 Pelrosimonia numandra, 1 Pheanthus ebracteolatus, 350 Pheanthine, 350, 356 Phdlodendron amurense, 329 Phenanthridine group, alkaloids, 406 Phenylalkylamines, 631 Phenyldehydrosparteine, pharmacological action, 152... 

The Pictet-Hubert reaction describes the construction of the phenanthridine nucleus (2) by dehydration of acyl-o-xenylamines (1). The application of zinc chloride at high temperature facilitates the dehydration/ This reaction is also referred as the Morgan-Walls Reaction. 

The acyl residue controls the formation and stability of the carbonium ion. If the carbonium ion is destabilized (by electron withdrawing groups), then cyclization to the phenanthridine nucleus will be sluggish. The slower the rate of cyclization, the greater the chance of side reactions with the cyclization reagent. Therefore, the yield of the phenanthridine will depend on the relative rates of cyclization and side reactions, which is controlled by the stability of the carbonium ion. 

The Pictet-Hubert reaction has found utility in the production of phenanthridine molecules that act as DNA-intercalator antitumor and antiviral agents (17). 

The major product of this reaction is the yellow, labile, 1 2 molar adduct (134) corresponding to the pyridine series, along with a small amount of a colorless compound (139) which is discussed later and some phenanthridine oxalate. The labile adduct is converted to the stable isomer (135) on heating in quinoline or pyridine. Oxidation of both these adducts with potassium permanganate in acetone gives phenanthridone as the major product. In the case of the labile adduct. 

Like acridine, phenanthridine and dimethyl acetylenedicarboxylate in methanol give a high yield of 1 1 1 molar adduct. Ultraviolet absorption spectrum comparisons show that this is best formulated as 9,10-dihydro-9-methoxy-10- (tran.s-l,2-dimethoxycarbonylvinyl) phenanthridine (142) rather than the corresponding phenanthridinium methoxide (143) under neutral conditions acidification changes the spectrum to that characteristic of the phenanthridinium cation. Crystallization of the adduct (142) from methanol containing 5-15% of water gave the betaine [(144) the positions of the ester and carboxylate groups have not been established], while in the presence... 

Diphenylquinoxaline and dimethyl acetylenedicarboxylate in methanol/ as in the phenanthridine case, combined to give a yellow pseudomethoxide (147) converted by acid into the corresponding quinoxalinium salt (148). Heating the adduct (147) with ethanolic potassium hydroxide gave 45% 2,3-diphenylquinoxaline, along with... 

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