A heterocyclic arene oxide. 5,6-Diphenylbenz[c]acridine 5,6-oxide

The first synthesis of a benz[c]acridine 5,6-oxide is described. Treatment of 5,6-benz[c]-acridinequinone with phenylmagnesium bromide results in the formation of a trans-diol, which gives the title compound upon dehydration with dimethylformamide dimethylacetal. In sulfuric acid, the epoxide rearranges mainly into 6,6-diphenyl-5-benz[c]acridone.     

5,6-Dimethylbenz[c]acridine functionalized in the 7-position

5,6-Dimethylbenz[c]acridines, functionalized in the 7-position by the carboxy, carbomethoxy, carboxamido, N-ethylcarboxamido, acetyl, cyano, chloro, methoxy or amino group are reported for the first time. Also various related 5,5-dimethyl-5,6-dihydrobenz[c]acridines including the 7-carbomethoxy, 6-hydroxy-7-carboxy, 6-bromo-7-carbomethoxy, 6-methoxy-7-carboxy, 6-methoxy-7-carbomethoxy, and 6-hydroxy-7-N-ethylcarboxamido derivatives which serve as precursors to the completely aromatized 5,6-dimethylbenz[c]acridines are also reported for the first time.     

Benzacridines VI.. Functional derivatives of 5,6-dimethylbenz[c]acridine

5,5-Dimethyl-5,6-dihydrobenz[c]acridone has been synthesized by three different routes: a, from a condensation of anthranilic acid with 4,4-dimethyl-1-tetraIone; b, by a catalytic hydrogenation of 2-(o-nitrobenzal)-4,4-dimethyl-1-tetralone oxide followed by an acid catalyzed cleavage of the oxide ring and closure of the nitrogen heterocyclic ring; c, a multi-step process starting with 7-carboxy-5,5-dimethyl-5,6-dihydrobenz[c]acridine. Several new functional derivatives of both 5,5-dimethyl-5,6-dihydrobenz[c]acridine and of 5,6-dimethylbenz[c]acridine were also produced for biological study by others.     

Theoretical reaction indices for dibenz[a,h]acridine

Huckel molecular orbital calculations and application of Seybold-Smith reactivity theory suggest that the Bay-Region diol epoxide derived from the 8,9,10,11-benzo ring of dibenz[a,h]acridine ( 1 ) is the same in reactivity as that of the 1,2,3,4-ring in agreement with experimental findings. The calculations dispute an earlier claim of regioselective reactivity at the 8,9,10,11-benzo ring.     

Synthesis of 2,3,8,9-tetramethoxy-11-phenyl-5,6-dihydrodibenz[2,3;7,8]indolizine

2,3,8,9-Tetramethoxy-11-phenyldibenz[2,3;7,8]indolizine was obtainedinhighyieldfrom (6,7-dimethoxyisoquinolin-1-yl)-(3,4-dimethylphenyl)phenylcarbinol by cyclization in the presence of formic acid. The behavior of (6,7-dimethoxyisoquinolin-1-yl)-(3,4-dimethoxyphenyl)methylcarbinol and (6,7-dimethoxyisoquinolin-1-yl-(3,4-dimethoxyphenyl)carbinol was studied under these same conditions. 2,3,7,8-Tetramethoxy-11-phenyl-5,6-dihydrodibenz[2,3;7,8]indolizine was obtained by hydrogenation on rhenium heptasulfide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1233–1238, September, 1993.     

Mono-, and dibenzacridine imines. Synthesis of 1a,11b- dihydrobenz[c]azirino[α]acridine, 4b,5a-dihydrodibenz[c,h]- azirino[α]acridine and 1a,13b-dihydrodibenz[c,j]azirino[α]acridine

The syntheses of the K-imine derivatives of benz[c]acridine, dibenz[c,h]acridine and dibenz[a,h]acridine are described. The parent hydrocarbons 1, 6 and 11 were oxidized with sodium hypochlorite under phase transfer conditions to the corresponding K-oxides 4,9 and 14 , which in turn were reacted with sodium azide. The resulting azido alcohols were then cyclized with tributylphosphine to the title compounds 5,10 and 15.     

Synthesis of 5,6,7-trimethylbenz[c]acridine

A new potential carcinogenic aromatic heterocyclic compound, 5,6,7-trimethylbenz[c]acridine ( 1 ), has been synthesized from the known 5,5-dimethyl-6-keto-5,6-dihydrobenz[c]acridine ( 4 ) using a series of reactions which includes an interesting new type of 1,4-conjugate addition cmploying lithium dimethylcopper.     

Behavior of 5,6-dihydrobenzo[h]cinnolinones towards hydrazine. Synthesis of benzo[h]cinnolinones and of 4-Aminobenzo[h]cinnolinones

Dehydrogenation and amination of 4,4a,5,6-tetrahydro and 5,6-dihydrobenzocinnolinones in refluxing hydrazine hydrate to give new benzo[h]cinnolinones and 4-aminobenzo[h]cinnolinones are reported, and reaction mechanisms proposed. Experiments were also extended to 4,4a-dihydro-5H-indenopyridazinone which underwent hydrazine induced dehydrogenation to 5H-indenopyridazin-3-one but not subsequent amination.     

Tetrahydroepoxides and diol epoxides of benz[c]acridine

The chemical synthesis and NMR characterization of the benzo ring tetrahydro- and diol epoxides of the carcinogen benz[c]acridine are described.     

Zur Synthese von 4-Aryl-5,6-dihydro-benzo[h]chinolinen

A new route to the benzo[h]quinoline system3 byMichael-addition of malononitrile to 2-arylidene-1-tetralones1 is presented. The mechanism of this reaction is elucidated by isolation of the intermediate 4H-naphtho[1,2—b]-pyrane2 and its reaction to3. The reaction is proposed to be a sequence of addition, cyclisation,Dimroth-rearrangement and disproportionation.

1. Mitt.:H.-H. Otto, Arch. Pharm. [Weinheim]307, 444 (1974).     

The synthesis of 5,6-dimethoxycyclopentano[h]-isoquinoline and derivatives

The synthesis of the previously unreported 5,6-dimethoxycyclopentano[h]isoquinoline ( 1 ) by way of a Pomeranz Fritsch ring closure of the diethyl acetal of 4,5-dimethoxy-7-indanylidene aminoacetaldehyde ( 3 ) is reported. Acetylation of the N-oxide of 1 yielded the corresponding N-acetyl-1-isoquinolone, which readily converted to the 1-isoquinolone on exposure to atmospheric moisture. Several diesters of the dihydroxy analog of 1 are reported.     

Synthesis of 6-fluoroalkylbenzo[h]cyclopenta[c]quinoline and -benzo[c]phenanthridine derivatives

Russian Chemical Bulletin -     

One-pot multicomponent synthesis of some 5,6-dihydro-benzo[h]quinoline derivatives

5,6-Dihydrobenzo[h]quinoline derivatives 4a–f and 5a–c were prepared via condensation of the corresponding arylidenes 2, with 1-tetralone in the presence of ammonium acetate and sodium methoxide, respectively, following thermal, microwave and ultrasound methodologies. The yields of 4a–f were moderate when the latter two methodologies used, but the products were pure. Ultrasound and microwave irradiation methods were also used in the synthesis of 4-aryl-3-cyano-1,2,5,6-tetrahydro-benzo[h]quinoline-2-ones (6a–e) and its analogues 7a,b. The majority of compounds 4–7 were synthesized via one-pot multicomponent reactions of aldehydes, active cyanomethylene compounds, 1-tetralone and ammonium acetate. Attempts to cyclocondensation of the aminocyano derivative 4a,d with acetic anhydride in presence of conc. H₂SO₄ failed; instead the acetylamino derivative 8 was isolated. On the other hand, refluxing of 4d with formamide in DMF led to the formation of dihydrobenzo-pyrimidoquinoline 9 giving good yield. All prepared condensates were structurally elucidated by various spectroscopic methods. Screening of the potential cytotoxicity for compounds 4a–f on five cell lines, namely: colorectal carcinoma (HCT-116), Hepatocellular carcinoma (HEPG2), Human breast adenocarcinoma (MCF7), Cervix adenocarcinoma (HELA) and Glioblastoma (U251), did not show any cytotoxic activity.     

Die Elektronenstruktur des Dicyclohepta[c d,g h]pentalens

Dicyclohepta[cd, gh]pentalene is shown by ESR.- and NMR.-spectroscopic evidence to be best represented as a perturbed [14] annulene. The orbital interaction between the π-perimeter and the ethylene-“bridge” is discussed.