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.     

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.     

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.     

An efficient synthesis of the new benzo[c]pyrido[2,3,4-kl]acridine skeleton

A series of molecules of therapeutic interest, possessing the new skeleton of 1H-benzo[c]pyrido[2,3,4-kl]acridine with acyl or aminoacyl and methoxy or aminoalkoxy substituents on the aromatic homocycles were synthesized by means of a Friedl?nder-type reaction. The requisite 5-aminodihydroquinoline-4-ones 1, whose preparation is described, were reacted with the appropriate alpha-tetralones 2 using an acidic catalyst (PPTS) under azeotropic conditions. Optimized reaction time and yield depend on temperature, which must not be below 90 degrees C.     

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.     

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.     

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.     

Benz[c]octalen

An expedient new synthesis of benzo[c]octalene starting from the Diels-Alder adduct of benzocyclobutadiene to 7,8-dimethylenecycloocta-1,3,5-triene is described. This octalene derivative, in solution, exists as an equilibrating mixture of the double bond isomers (2) and (3) whereas in its crystalline state only the isomer (2) is present.     

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

Russian Chemical Bulletin -     

Hydroacridines and related compounds 19. Angular hydride reductions in the hydrobenz[c]acridine and hydroacridine series

The hydride reduction of dihydro- and tetrahydropyridine derivatives and of angular nitriles in the hydrobenz[c]acridine and hydroacridine series, and also the reductive cleavage of the azoline and azine rings in 11a,12-benzoxazolino- and 11a,12-benzoxazinohydrobenz[c]acridines and 4a,10-benzoxazolinohydroacridines has been studied. The stereospecificity of all the reactions mentioned has been established.For communication 18, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 508–513, April, 1980.     

Cyclopenta[c]pyrans

Natural occurrence, synthesis, chemical behavior, and physical properties of aromatic cyclopenta[c]pyrans are reviewed. Various strategies for the synthesis of cyclopenta[c]pyrans starting from cyclopentadienes, fulvenes, oxadiazinones, or α‐pyrones were developed according to the substitution patterns of the target compounds. J. Heterocyclic Chem., (2011).