The synthesis of all of the monomethyl isomers of benzo[b]naphtho[1,2-d]thiophene

All isomers of the monomethylbenzo[bnaphtho[1,2-d]thiophenes were synthesized by photocyclization of 2-styrylbenzo[b]thiophenes which were prepared by the Wadsworth-Emmons reaction or the Wittig reaction.     

Synthesis of 8-substituted naphtho[2,1-b]thiophenes with cationic side chains at position 4

A series of five 8-substituted α-[bis(2-hydroxyethyi)aminoethyl]naphtho[2,1-b]thiophenes 7 and a series of seven N-(3-dimethylaminopropyl)-8-substituted naphtho[2,1-b]thiophene-4-carboxamides 8 have been synthesized. The naphtho[2,1-b]thiophene-4-carboxylic acids 4 were prepared by photooxidative cyclization of α-(2-thienyi)-β-arylacrylic acids 3. The carboxylic acids 4 were converted by a conventional five step route involving α-bromoketone intermediates to the a-[bis(2-hydroxyethyl)aminomethyl]-8-substituted naphtho-[2,1-6]thiophene-4-methanols 7 and by a standard two-step amide preparation to the N-(3-dimethylaminopropyl)-8-substituted naphtho[2,1-6]thiophene-4-carboxamides 8 .     

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.     

Photocyclization of 2-[1]benzothien-3-yl)-3-phenylpropenoic acids

Photocyclization of the substituted 2-([1]benzothien-3-yl)-3-phenylpropenoic acids 3a-c in the presence of iodine and air in a benzene-cyclohexane mixture afforded a separable mixture of three compounds, benzo[b]naphtho[2,1-d]thiophene-6-carboxylic acids 4a-c , 6H-benzo[b]naphtho[2,3-d]thiopyran-6-ones 5a-c , and 10-methoxy-2-methyl-6H-benzo[b]naphtho[2,3-d]pyran-6-one ( 6 ).     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 5. [1]Benzothieno[2,3-c]naphtho[2,1-f]-quinoline and [1]benzothieno[2,3-c]naphtho[1,2-g]quinoline

Two previously unknown heterocyclic ring systems, namely, [1]benzothieno[2,3-c]naphtho[2,1-f]quinoline ( 4 ) and [1]benzothieno[2,3-c]naphtho[1,2-g]quinoline ( 5 ) were synthesized via photocyclization of 3-chloro-N-(2-phenanthryl)benzo[b]thiophene-2-carboxamide ( 8 ) followed by chlorination and dechlorination. The total assignment of their ¹H- and ¹³C-nmr spectra was determined by utilizing inverse-detected HMQC and HMBC two-dimensional nmr spectroscopic methods.     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 8 . [1]Benzothieno[2,3-c]naphtho[1,2-h]quinoline and [1]benzothieno[2,3-c]naphtho[1,2-h][1,2,4]triazolo[4,3-a]quinoline

The previously unknown polycyclic heterocyclic ring systems, namely, [1]benzothieno[2,3-c]naphtho[1,2-h]-quinoline and [1]benzothieno[2,3-c]naphtho[1,2-h][1,2,4]triazolo[4,3-a]quinoline were synthesized via photocyclization of 3-chloro-N-(1′-phenanthryl)benzo[b]thiophene-2-carboxamide.     

Cascade cyclization of aryldiynes using iodine: synthesis of iodo-substituted benzo[b]naphtho[2,1-d]thiophene derivatives for dye-sensitized solar cells

A facile, efficient, and general synthetic method for iodo-substituted benzo[b]naphtho[2,1-d]thiophenes has been developed via a cascade cyclization of thioanisole-substituted aryldiynes using iodine. A new donor–π linker–acceptor (D–π–A) organic dye, G1, with the benzo[b]naphtho[2,1-d]thiophene moiety as an electron donor has been synthesized, and the performance of dye-sensitized solar cell based on G1 has been investigated.     

The synthesis of novel polycyclic heterocyclic ring system via photocyclization. 18. Benzo[h]naphtho-[1′,2′:4,5]thieno[2,3-c]quinoline and benzo[h]naphtho-[1′,2′:4,5]thieno[2,3-c] [1,2,4]triazolo[4,3-a]quinoline

The synthesis of two previously unknown polycyclic ring systems, benzo[h]naphtho[1′2′:4,5]-thieno[2,3-c]quinoline ( 1 ) and benzo[h]naphtho[1′,2′:4,5]thieno[2,3-c][1,2,4]triazolo[4,3-a]quinoline ( 2 ), was achieved via oxidative photocyclization of 1-chloro-N-(1-naphthyl)naphtho[2,1-b]thiophene-2-carboxamide ( 5 ). The total assignment of their ¹H and ¹³C nmr spectra was determined by the concerted use of two-dimensional nmr methods.     

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.     

Some methyl substituted benzo[b]naphtho[2,3-d]thiophenes

Seven benzo[b]naphtho[2,3-d]thiophenes have been prepared with methyl groups substituted in the 6,7, and 8-positions. These compounds are structurally related to the sulfur analogs of cholanthrene and methylcholanthrene.     

Syntheses of thiopyrone and pyrone derivatives by photocyclization reaction of 3‐aryl‐2‐( Benzothien‐3‐yl)propenoic acids

Naphtho[1,2‐b][1]benzothiophene‐6‐carboxylic acids, 6H‐benzo[b]naphtho[2,3‐d]thiopyran‐6‐ones and 6H‐benzo[b]naphtho[2,3‐d]pyran‐6‐ones were synthesized in one step by the photocyclization reaction of 3‐aryl‐2‐([1]benzothien‐3‐yl)propenoic acids. The photocyclization reaction did not occur when the 3‐aryl group contained the electron‐withdrawing nitro group. The assignment of the ¹H and ¹³C nmr spectra of 6H‐benzo[b]naphtho[2,3‐d]thiopyran‐6‐one and 6H‐benzo[b]naphtho[2,3‐d]pyran‐6‐one by two‐dimensional nmr methods is described. The difference between the chemical shift values of H12 for these two compounds is attributed to different molecular geometries.     

The synthesis of benzo[b]phenanthro[d]thiophenes and anthra[b]benzo[d]thiophenes

The synthesis of benzo[b]phenanthro[2, 3-d]thiophene ( 5 ), benzo[b]phenanthro[4, 3-d]thiophene ( 6 ), benzo-[b]phenanthro[2, 1-d]thiophene ( 9 ), benzo[b]phenanthro[3, 2-d]thiophene ( 14a ), anthra[1, 2-b]benzo[d]thiophene ( 24 ), anthra[2, 3-b]benzo[d]thiophene ( 29 ) and anthra[2, 1-b]benzo[d]thiophene ( 30 ) is described as well as the preparation of 13-methylbenzo[b]phenanthro[3, 2-d]thiophene ( 14b ).     

Benzo[b]naphtho[2,1-d]thiophene (thiachrysene) derivatives as potential carcinostatic molecules

About twenty compounds of the benzo[b]naphtho[2,1-d]thiophene series have been synthesized, namely, 6-amino derivatives, with the aim of biological testing as possible carcinostatic molecules.     

Synthesis of 6-aminobenzo[b]naphtho[2,1-d]thiophene

6-Aminobenzo[b]naphtho[2,1-d]thiophene has been prepared by two different routes, one, a one-pot synthesis.     

Synthesis of benzo[4,5]phenaleno[1,9-bc]thiophene and benzo[4,5]phenaleno[9,1–6c]thiophene

Two pentacyclic thiophenes, benzo[4,5]phenaleno[1,9–6c]thiophene ( 1 ) and benzo[4,5]phenaleno[9,1-bc]-thiophene (2) were synthesized via the corresponding 3-methylphenanthro[2,1-b]thiophene (7) and 1-methylanthra[2,1–6]thiphene ( 19 ).     

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.     

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 ).     

A new approach for the synthesis of some pyrazolo[5,1‐c]triazines and pyrazolo[1,5‐a]pyrimidines containing naphtofuran moiety

Naphtho[2,1‐b]furan‐2‐yl)(8‐phenylpyrazolo[5,1‐c][1,2,4]triazin‐3‐yl)methanone, ([1,2,4]triazolo[3,4‐c][1,2,4]triazin‐6‐yl)(naphtho[2,1‐b]furan‐2‐yl)methanone, benzo[4,5]imidazo[2,1‐c][1,2,4]triazin‐3‐yl‐naphtho[2,1‐b]furan‐2‐yl‐methanone, 5‐(naphtho[2,1‐b]furan‐2‐yl)pyrazolo[1,5‐a]pyrimidine, 7‐(naphtho[2,1‐b]furan‐2‐yl)‐[1,2,4]triazolo[4,3‐a]pyrimidine, 2‐naphtho[2,1‐b]furan‐2‐yl‐benzo[4,5]imidazo[1,2‐a]pyrimidine, pyridine, and pyrazole derivatives are synthesized from sodium salt of 5‐hydroxy‐1‐naphtho[2,1‐b]furan‐2‐ylpropenone and various reagents. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation, and alternative synthetic route whenever possible. J. Heterocyclic Chem., (2012).     

New ‘2-phenylnaphthalene’-mediated synthesis of benzo[b]naphtho[2,3-d]furan-6,11-diones and 6-oxa-benzo[a]anthracene-5,7,12-triones: first total synthesis of 6-oxa-benzo[a]anthracen-5-ones

We describe here a novel synthesis of benzo[b]naphtho[2,3-d]furan-6,11-diones based on the heteroannulation of 2-(2-bromophenyl)-3-hydroxy-1,4-naphthoquinones. The naphthoquinones were prepared from 3-(2-bromophenyl)naphthalen-2-ols, which were obtained by intramolecular aldol condensation of 2-[3-(2-bromophenyl)-2-oxo-propyl]benzaldehydes. Alternatively, benzo[b]naphtho[2,3-d]furan-6,11-diones were obtained more directly and efficiently by cyclization of 3-(2-bromophenyl)naphthalen-2-ols to benzo[b]naphtho[2,3-d]furans and oxidation of the resulting compounds. Furthermore, the first 6-oxabenzo[a]anthracen-5-one described was similarly obtained from 2-[3-(2-formylphenyl)-2-oxopropyl]benzoic acid and oxidized to 6-oxa-benzo[a]anthracene-5,7,12-trione.     

The synthesis of novel polycyclic heterocyclic ring systems. 3. Synthesis and NMR spectroscopy of 15-chloro[1]benzo-thieno[2″,3″:3′,4′]naphtho[1′,2′:4,5]thieno[2,3-c]quinoline

The polycyclic heterocyclic compound with a novel ring system, 15-chloro[1]benzothieno[2″,3″:3′,4′]-naphtho[1′,2′:4,5]thieno[2,3-c]quinoline was synthesized via photocyclization of 3-chloro-N-phenyl[1]-benzothieno[2′,3′:3,4]naphtho[2,1-b]fhiophene-2-carboxamide followed by chlorination with phosphorus oxychloride. The assignment of its ¹H and ¹³C nmr spectra was accomplished by utilizing two-dimensional nmr methods.