Synthesis of novel benzo naphtho naphthyridines from 2,4-dicloroquinolines

A schematic study on the condensation of 2,4-dichloroquinolines ( 1 ) with 1-naphthyamine ( 2 ) in the presence of CuI as a catalyst to functionalized mono ( 3 ) and di ( 4 ) substituted naphthylamino quinolines was described. Consequently, these mono- and di-substituted amines on polyphosphoric acid-catalyzed cyclization reaction with p-toluic acid and acetic acid to yield the linear benzo[b]naphtho[2,1-g][1,8]naphthyridines ( 5 ) and angular benzo[b]naphtho[2,1-h] naphthyridines ( 6 ) in good yields. In addition to descried the similar synthesis of benzo[g]naphtho [2,1-b][1,8]naphthyridines ( 12 ) and benzo[h]naphtho[2,1-g][1,8]naphthyridines ( 13 ) from 2,4-dichlorobenzo[h]quinoline ( 8 ) with various anilines ( 9 ) through my intermediates ( 10 and 11 ).     

Angular polycyclic thiophenes containing two thiophene rings. Part II

The syntheses of naphtho[1,2–6:7,6-b′]bisbenzo[b]thiophene ( 4 ), naphtho[1,2–6:7,8-b′]bisbenzo[b]thiophene ( 5 ), naphtho[2,1-b:7,6-b′]bisbenzo[b]thiophene ( 8 ), naphtho[2,1-b:7,8-b′]bisbenzo[b]thiophene ( 9 ), naphtho-[1,2–6:5,6-b′]bisbenzo[b]thiophene ( 14 ), naphtho[1,2–6:6,5-b]bisbenzo[b]thiophene ( 17 ) and naphtho[2,1–6:-6,5-b′]bisbenzo[b]thiophene ( 23 ) are reported.     

Synthesis of benzo[b]phenanthro[d]thiophenes

The synthesis of benzo[b]phenanthro[1,2-d]thiphene ( 1 ), benzo[b]phenanthro[4,3-d]thiophene ( 2 ), benzo-[b]phenanthro[2,1-d]thiophene ( 3 ) and benzo[b]phenanthro[3,4-d]thiophene ( 4 ) from appropriately substituted olefines by photochemical cyclodehydrogenation is described. The photolysis of olefin 9 gave a mixture of 4 and anthra[1,2-b]benzo[d]thiophene ( 5 ).     

The insertion and extrusion of heterosulfur bridges. XV. S-bridging of 2,2′-binaphthyl and 1-(2-naphthyl)cyclohexene. Studies on hydrodehalogenation during the reaction

Regioselectivity occurs in the sulfur-bridging reactions of 2,2′-binaphthyl (1) and 1-(2-naphthyl)cyclohexene (7) by means of hydrogen sulfide and a chromia-alumina-magnesia catalyst (designated I) in a flow apparatus at 550°. Thus, 1 gives a higher yield (6.1%) of dinaphtho[1,2–6:2′,l'-d]thiophene from 1,1′-bridging than of dinaphtho[1,2-b:2′,3′-d]thiophene (3.4%) from l,3′-bridging. No product expected from 3,3′-bridging was identified. Substrate 7 undergoes both dehydrogenation and bridging to yield 2-phenylnaphthalene (8%), benzo[b]naphtho[2,1-d]thiophene (9%) from alpha bridging, and benzo[b]naphtho[2,3-d]thiophene (3%) from beta bridging into the naphthalene ring. Exploratory studies showed that either sulfided catalyst I or a sulfided molybdenum( VI ) oxide-alumina-cobalt( II ) oxide catalyst ( II ) effects hydrodehalogenation of various monohalo- and polyhaloarenes (where halo, X, is chloro or bromo) at 450–550°. In the biphenyl, phenanthrene, naphthalene, and pyrene systems, halogen was lost either under sulfur-bridging conditions or under hydrogenolysis conditions, i.e. with methanol as a reactant. For every substrate the parent arene was isolated or identified as a reaction product. In selected experiments, acid HX was also identified in the effluent. Use of hydrogen sulfide as a reactant led to formation of dibenzothiophene and phenanthro[4,5-bcd]thiophene as main products in the biphenyl and phenanthrene systems, respectively; while use of methanol as a reactant gave small amounts of methyl bromide (for X = Br) and methylarenes.     

Preparation of imidazo[2,1-b]quinazolin-5(3H)-ones and related tricyclic systems using a novel,double displacement reaction

New methodology is described for the construction of tricyclic heterocycles. Thus, a double displacement reaction of l-(2-fluorobenzoyl)-2-methylthio-2-imidazoline ( 8a ) with 1,1-dialkylhydrazines gave 10-substituted 2,10-dihydroimidazo[2,1-b]quinazolin-5(3H)-ones in good yield. The corresponding 1-(2-nitrobenzoyl)-2-meth-ylthio-2-imidazolines also underwent double displacement reactions with hydrazines. Other tricyclics made using double displacement reactions were pyrimido[2,1-b]quinazolines, imidazo[1,2-a]pyrido[2,3-d]pyrimidines, and imidazo[1,2-a]pyrazolo[3,4-d]pyrimidines. Treatment of 8a with hydrazine hydrate or methylhydrazine gave products resulting from displacement, but did not afford fused benzotriazepinones.     

Angular polycyclic thiophenes containing two thiophene rings. I

We describe the synthesis of thieno[2,3-c]dibenzothiophene ( 6 ), thieno[3,2-c]dibenzothiophene ( 10 ), thieno-[3,2-a]dibenzothiophene ( 14 ), thieno[2,3-a]dibenzothiophene ( 16 ), benzo[1,2-b:4,3-b]bisbenzo[b]thiophene ( 18 ), benzo[1,2--6:3,4-b]bisbenzo[b]thiophene ( 20 ), benzo[2,1--6:3,4-b]bisbenzo[b]thiophene ( 22 ), benzo[1,2-b:3,4-g]bisbenzo[b]thiophene ( 27 ), benzo[1,2-b:4,3-e]bisbenzo[b]thiophene ( 29 ), benzo[2,1--6:3,4-g]bisbenzo[b]thiophene ( 36 ), benzo[2,1--6:4,3-e]bisbenzo[b]thiophene ( 38 ), benzo[1,2--6:4,3-g]bisbenzo[b]thiophene ( 41 ), benzo[1,2-b:4,5-g]bisbenzo[b]thiophene ( 42 ), benzo[1,2-b:3,4-e]bisbenzo[b]thiophene ( 44 ) and benzo-[1,2-b:5,4-e]bisbenzo[b]thiophene ( 45 ).     

Diels‐alder reactions of 2‐(2‐nitroethenyl)‐1H‐pyrroles and their oxygen and sulfur analogs with quinones

Diels‐Alder reaction of 2‐(E‐2‐nitroethenyl)‐1H‐pyrrole ( 2a ) with 1,4‐benzoquinone gave the desired benzo[e]indole‐6, 9(3H)‐dione ( 4a ) in 10% yield versus a 26% yield (lit. 86% [5]) of the known N‐methyl compound ( 4b ) from the N‐(or 1)‐methyl compound ( 2b ). Protection of the nitrogen of 2a with a phenylsul‐fonyl group ( 2c ) gave a 9% yield of the corresponding N‐(or 3)‐phenylsulfonyl compound ( 4c ). The reaction of 2b with 1,4‐naphthoquinone gave in 6% yield (lit. 64% [5]) the known 3‐methylnaphtho[2,3‐e]‐indole‐6, 9(3H)‐dione ( 6 ). The reaction of 2‐(E‐2‐nitroethenyl)furan ( 8a ) gave a small yield of the desired naphtho[2,1‐b]furan‐6, 9‐dione ( 9a ), recognized by comparing its NMR spectrum with that of 4b. The corresponding reaction of 2‐(E‐2‐nitroethenyl)thiophene ( 8b ) gave a 4% yield of naphtho[2,1‐ b ]thiophene‐6,9‐dione ( 9b ), previously prepared in 24% yield [12] in a three‐step procedure involving 2‐ethenylthiophene. Introducing an electron‐releasing 2‐methyl substituent into 8a and 8b gave 12a and 12b , which, upon reaction with 1,4‐benzoquinone, gave 2‐methylnaphtho[2,1‐b]furan‐6, 9‐dione ( 13a ) and its sulfur analog ( 13b ) in yields of 4 and 8%, respectively.     

Photochemical synthesis of heteroatom-containing polycyclic aromatic compounds

Anthra[2,1-b]furan, anthra[2,1-b]benzo[d]furan, anthra[2,1-b]thiophene, anthra[1,2-b]thiophene, anthra[2,1-b]benzo[d]thiophene, anthra[2,1-b]pyrrole and naphtho[2,3-c]carbazole derivatives were synthesized in fairly good yields by a one-pot photocycloaddition reaction of 2,3-disubstituted 1,4-naphthoquinone with 1,1-diarylethylene. This is the first reported synthesis of these aromatic compounds.     

<Emphasis Type="Italic">N</Emphasis>-bridged heterocycles: regiospecific synthesis of 2-methyl-4H-pyrimido[2,1-<Emphasis Type="Italic">b</Emphasis>]benzothiazol-4-ones

N-bridged heterocycles, 2-methyl-4H-pyrimido[2,1-b]benzothiazol-4-ones, have been synthesized in quantitative yield by the reaction of 2-aminobenzothiazoles with ethylacetoacetate in the presence of polyphosphoric acid involving dehydrative condensation followed by cyclization. The possibility of the formation of 4-methyl-2H-pyrimido[2,1-b]benzothiazol-2-ones has been excluded on the basis of spectral studies.     

Synthesis of anthra[b]thiophenes and benzo[b]naphtho[d]thiophenes

All isomers of the parent anthra[b]thiophenes and benzo[b]naphtho[d]thiophenes, namely anthra[2,3-b]thio-phene, anthra[2,1-b]thiophene, anthra[1,2-b]thiophene, benzo[b]naphtho[2,3-d]thiophene, benzo[b]naphtho[2,1-d]thiophene and benzo[b]naphtho[1,2-d]thiophene were synthesized using a new procedure.     

Benzannelated analogs of phenanthro[1,2-b]- and [2,1-b]thiophene: Synthesis and structural characterization by two-dimensional NMR and X-ray techniques

Syntheses of benzo[3,4]phenanthro[1,2-b]thiophene, benzo[3,4]phenanthro[2,1-b]thiophene and their 1-methyl analogs are reported as potential constituents of solvent refined coal liquids and for mutagenicity testing. The attempted synthesis of the 13-methyl analogs which gave the 11-methyl isomers is also described. Total assignments of the ¹H- and ¹³C-nmr spectra based on long range optimized heteronuclear protoncarbon two-dimensional chemical shift correlation are reported. Carbon assignments obtained for benzo[3,4]-phenanthro[1,2-b]thiophene using this approach were confirmed with a 125 MHz ¹³C–¹³C INADEQUATE spectrum. X-Ray crystal structures were determined for benzo[3,4]phenanthro[1,2-b]thiophene and 1-methyl-benzo[3,4]phenanthro[2,1-b]thiophene. Both molecules were helically distorted from planarity. Close intramolecular contacts between the bay region H1–H13 and ClMe-H13 of 2.03 and 2.28 Å, respectively, were responsible for the distortions. There were no close intermolecular contacts of <3.5Å. both molecules refined to an R value of <0.05.     

Beiträge zur Chemie schwefelhaltiger Heterocyclen, 4. Mitt.: 6H-Benz[b]indeno[1,2-d]thiophen und 10H-Benz[b]indeno-[2,1-d]thiophen

Zusammenfassung Intramolekulare Cyclisierungsreaktionen von 3-Phenyl-benzo[b]thiophen-2-carbonsäurechlorid und von 2-Phenyl-benzo[b]thiophen-3-carbonsäurechlorid lieferten 6-Oxo-6H-benz[b]indeno[1,2-d]thiophen bzw. 10-Oxo-10H-benz[b]indeno[2,1-d]thiophen.

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Contributions to the chemistry of sulfur containing heterocycles, IV.: 6H-Benzo[b]indeno[1,2-d]thiophene and 10H-benzo-[b]indeno[1,2-d]thiophene

Intramolecular cyclization reactions of 3-phenyl-benzo[b]thiophene-2-carbonyl chloride and of 2-phenyl-benzo[b]-thiophene-3-carbonyl chloride gave 6-oxo-6H-benz[b]indeno-[1,2-d]thiophene and 10-oxo-10H-benz[b]indeno[2,1-d]thiophene, respectively.

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3. Mitt.:F. Sauter, Mh. Chem.99, 2100 (1968).     

The insertion and extrusion of heterosulfur bridges. XI. Desulfurizations of condensed thiophenes by means of methanol and a molybdena catalyst

Desulfurizations of 2-methyl- ( 1b ), 4-methyl- ( 1c ), and 4,6-dimethyldibenzothiophenes ( 1d ), benzo[b]thiophene ( 2 ), and benzo[b]naphtho[2,1-d]thiophene ( 5 ) were effected by means of methanol and a sulfided CMA catalyst [a mixed oxide of Co(II), Mo(VI), and Al(III)] at 450°. Desulfurization was accompanied by processes of demethylation and ring hydrogenation in the case of 1d and by both methylation and demethylation in the cases of 1b and 1c . Compound 2 gave ethylbenzene (80%), while 5 produced 2-phenylnaphthalene (69%).     

Synthesis of phenanthro[b]thiophenes

All isomers of the parent phenanthro[b]thiophenes, namely, phenanthro[1,2-b]thiophene, phenanthro-[2,1-b]thiophene, phenanthro[2,3-b]thiophene, phenanthro[3,4-b]thiophene, phenanthro[3,4-b]thiophene, phenanthro[4,3-b]thiophene and phenanthro[9,10-b]thiophene have been synthesized.     

Synthesis of N(3-dimethylaminopropyl)-6-substituted naphtho[2,1-b]thiophene-4-carboxamides

A series of N-(3-dimethylaminopropyl)-6-substituted naphtho[2,1-b]thiophenes-4-carboxamides have been synthesized. 6-Substituted naphtho[2,1-b]thiophene-4-carboxylic acids were obtained upon oxidative-photo-cyclization of α-(2-thienyl)-β-arylacrylic acids. The naphtho[2,1-b]thiophene carboxylic acids were converted to the corresponding amides through their acid chlorides or, in one case, by use of 1,1-carbonyldiimidazole coupling of the amine and the acid.     

Synthesis of pyreno[b]thiophenes

The synthesis of all the isomers of pyreno[b]thiophene namely, pyreno[1,2-b]thiophene, pyreno[2,1-b]thiophene and pyreno[4,5-b]thiophene is described. Their spectral characteristics are also discussed.     

Nitrogen bridgehead compounds. Part 72 Straightforward synthesis of 1,2,3,4-tetrahydrorutaecarpine and derivatives

In polyphosphoric acid, the Fischer indolization of 6-arylhydrazono-1,2,3,4,6,7,8,9-octahydro-11H-pyrido-[2,1-b]quinazolin-11-ones, obtained from 1,2,3,4,6,7,8,9-octahydro-11H-pyrido[2,1-b]quinazolin-11-ones by three pathways, afforded substituted 1,2,3,4,7,8-hexahydro-5H-13H-indolo[2′,3′:3,4]pyrido[2,1-b]quinazolin-5-ones in high yields. The structures of the 6-substituted octahydropyridoquinazolinones and hexahydroindo-lopyridoquinazolinones were characterized by uv, ¹H and ¹³C nmr data.     

Synthesis of triphenyleno[b]thiophenes

The synthesis of all the isomers of triphenyleno[b]thiophenes namely, triphenyleno[l,2-b]thiophene, triphenyleno[2,1-b]thiophene and triphenyleno[2,3-b]thiophene is described.     

Synthesis of 1-hydrazinopyridazino[4,5-b]quinoxaline and related compounds

This paper describes the synthesis of 1-hydrazinopyridazino[4,5-b]quinoxaline ( 10 ), tetrazolo[4,3-b]pyridazino[4,5-b]quinoxaline ( 11 ) and some 1,2,4-triazolo[4,3-b]pyridazino[4,5-b]quinoxalines 13 . Starting with 2-ethoxycarbonyl-3-methylquinoxaline 1,4-dioxide ( 1 ), 1,2-dihydro-1-oxopyridazino[4,5-b]quinoxaline ( 5 ) was prepared by three different ways: (a) chlorination of 1 in acetic acid gave 2-ethoxycarbonyl-3-dichloromethylquinoxaline 1,4-dioxide, which reacts with an excess of hydrazine to give about 60% of 5 ; (b) oxidation of 1 with selenium dioxide gave 90% of 2-ethoxycarbonyl-3-formylquinoxaline 1,4-dioxide ( 3 ), which reacts with hydrazine to give 5 (63%); (c) compound 3 was treated with hydrazine to give 1,2-dihydro-1-oxopyridazino-[4,5-b]quinoxaline 1,4-dioxide ( 4 ) (70%), which by reduction with sodium dithionite gave 5 (80%). Compound 5 reacts with phosphorus pentasulfide or the Lawesson reagent to give 1,2-dihydro-1-thiocarbonylpyridazino[4,5-b]quinoxaline ( 9 ), which treated with hydrazine gave 5 (80%). This last compound reacts with nitrous acid to give 11 . Some hydrazones 12 from 10 are described. Heating the aldehyde hydrazones 12a,c,d with dimethylsulfoxide some 1,2,4-triazolo[4,3-b]pyridazino[4,5-b]quinoxalines 13 were obtained. Compound 13a was also obtained in the reaction of 10 with benzoyl chloride. Reaction of 3 with phenylhydrazine gave 1,2-dihydro-1-oxo-2-phenylpyridazino[4,5-b]quinoxaline ( 6 ). Reactions of 5 with acetic anhydride and dimethylsulfate gave, respectively, 1-acetoxypyridazino[4,5-b]quinoxaline ( 8 ) and 1,2-dihydro-1-oxo-2-methylpyridazino-[4,5-b]quinoxaline ( 7 ). All the compounds were characterized by elemental analysis and ¹H-nmr spectra. Compounds 5 and 10 showed antihypertensive activity in rats.     

An efficient approach to isoindolo[2,1-b][2]benzazepines via intramolecular [4+2] cycloaddition of maleic anhydride to 4-α-furyl-4-N-benzylaminobut-1-enes

Acylation of 4-α-furyl-4-N-benzylaminobut-1-enes with maleic anhydride gave 4-oxo-3-aza-10-oxatricyclo[5.2.1.0^1,5]dec-8-ene-6-carboxylic acid via amide formation followed by intramolecular Diels-Alder reaction of furan (IMDAF). The cycloaddition proceeded under mild reaction conditions (25 °C) and provided only the exo-adduct in quantitative yield. Treatment of this compound with PPA gave isoindolo[2,1-b][2]benzazepine derivatives via ring opening, aromatization and intramolecular electrophilic alkylation. In order to extend the scope of the reaction sequence, 7-oxo-5,11b,12,13-tetrahydro-7H-isoindolo[2,1-b][2]benzazepine-8-carboxylic acids were further transformed into useful synthetic intermediates.