Synthesis of imidazobenzothiazine and primidobenazothiazine derivatives via the classic Ullmann cross-coupling reaction of 1,8-diiodonaphthalene with 1H-benzo[d]imidazole-2-thiols or 2-thiouracils

A feasible protocol for the synthesis of imidazobenzothiazine and primidobenazothiazine derivatives via the classic copper(I)-catalyzed Ullmann cross-coupling process has been developed. 1,8-Diiodonaphthalene could couple with 2-mercaptobenzimidazoles or 2-thiouracils to give the corresponding benzo[4,5]imidazo[2,1-b]naphtho[1,8-de][1,3]thiazines and 11H-naphtho[1,8-de]pyrimido[2,1-b][1,3]thiazin-11-ones in moderate yields.     

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.     

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).     

Synthetic utility of a heterocyclic o-aminoaldehyde: synthesis of pyrazolopyridopyrimidines, pyrazolonaphthyridines, and pyrazolopyrimidonaphthyridinones

Abstract  

A series of various polysubstituted pyrazolo[3,4-h][1,6]naphthyridines, benzo[b]pyrazolo[3,4-h][1,6]naphthyridines, and pyrazolo[4′,3′:5,6]pyrido[4,3-d]pyrimidines were synthesized by Friedl?nder condensation of 4-amino-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbaldehyde (o-aminoaldehyde) with active methylene compounds. The o-aminoaldehyde was functionalized to o-aminonitrile and o-aminocarboxamide with malononitrile and cyanoacetamide, respectively, which on condensation with monosubstituted ureas and acetic anhydride, respectively, afforded pyrazolo[3,4-h]pyrimido[4,5-b][1,6]naphthyridines.     

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.     

Synthesis and Spectroscopic Distinction of Benzonaphthonaphthyridine and Its Isomer

Distinction of benzo[h]naphtho[1,2-b][1,6]naphthyridine and its isomeric benzo[b]naphtho[1,2-h][1,6]naphthyridine is well explained on the basis of various spectroscopic techniques. Initially these isomers were prepared from their respective chloroquinolines via anilinoquinolines as potential intermediates. Spectroscopic dissimilarities of their precursors and intermediates have also been considered and compared with the final benzonaphthonaphthyridine isomers.     

Photocyclization of 2-(naphth-1-yl)-3-(thien-2-yl)propenoic acid and the total assignment of the 1H- and 13C-NMR spectra of the product

Photocyclization of the substituted 2-(naphth-1-yl)-3-(thien-2-yl)propenoic acid ( 3 ) in the presence of iodine and air in a benzene-cyclohexane mixture afforded a separable mixture of three compounds, phenanthro[2,1-b]thiophene-10-carboxylic acid ( 4 ), phenanthro[2,1-b]thiothene ( 5 ), and naphtho[1,8-cde]-thieno[3,2-g][2]benzopyran ( 6 )     

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.     

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

All isomers of the monomethylbenzo[b]naphth[2,1-d]thiophenes were synthesized using photocyclization of 3-styrylbenzo[b]thiophenes. The 1-, 3-, 4-, and 5-methylbenzo[b]naphtho[2,1-d]thiophenes were synthesized by irradiation of the corresponding methylated 3-styrylbenzo[b]thiophenes which were prepared by the Wadsworth-Emmons reaction of diethyl benzo[b]thenylphosphonate with o-, m-, p-tolualdehyde and acetophenone. The 7-, 8-, 9- and 10-methylbenzo[b]naphtho[2,1-d]thiophenes were synthesized by decarboxylation of 7-, 8-, 9- and 10-methylbenzo[b]naphtho[2,1-d]thiophene-6-carboxylic acid with copper in quinoline. These carboxylic acids were prepared by photocyclization of the corresponding 2-(benzo[b]thiophen-3-yl)-3-phenylpropenoic acids which were prepared by the condensation of the methylated benzo[b]thiophene-3-ylacetic acids with benzaldehyde in the presence of triethylamine in acetic anhydride.     

Construction of new heteroacenes based on benzo[b]thieno[2,3-d]thiophene / quinoline or 1,8-naphthyridine systems using the Friedländer reaction

Two new classes of heteroacenes, namely benzo[4′,5′]thieno[2′,3′:4,5]thieno[3,2-b]quinolines and benzo[4′,5′]thieno[2′,3′:4,5]thieno[3,2-b][1,8]naphthyridines, have been formed using the Friedländer reaction to annulate the benzo[b]thieno[2,3-d]thiophene scaffold to quinoline or 1,8-naphthyridine fragments. In accordance with this synthetic strategy, benzo[b]thieno[2,3-d]thiophen-3(2H)-ones were treated with 2-aminobenzaldehydes or 2-aminonicotinaldehyde in the presence of pyrrolidine in glacial acetic acid at reflux to give the desired quinoline- or 1,8-naphthyridine-fused compounds, respectively. The optical and electrochemical properties of selected heteroacenes were determined.     

The synthesis of novel polycyclic heterocyclic ring systems. 2. Naphmo[2,1-b:4,3-g]bisbenzo[b]thiophene

The novel polycyclic heterocyclic ring system, naphtho[2,1-b:4,3-g]bisbenzo[b]thiophene was synthesized from 5-[2-(2-bromo-3-thienyl)ethenyl]naphtho[2,1-b][1]benzothiophene. The assignment of its ¹H and ¹³C nmr spectra was also accomplished by utilizing two-dimensional nmr methods.     

Neue N-Heterocyclen aus Enaminoketonen

The reaction of aliphatic or cyclic enaminoketones with pyridine or pyrimidine derivatives leads to pyrido[2.3-d]-pyrimidines (3 a-h), benzo[6.7]cyclohepta[1.2: 4.5]pyrido-[ [2.3-d]pyrimidines (6 a-c), benzo[f]pyrimido[4.5-c]isoquinolines (6 d-e), benzo[3.4]cyclohepta[1.2-c][1.6]naphthyridines (7 a) and naphtho[2.1-c][1.6]naphthyridines (7 b).     

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.     

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.     

N-substituierte Aminomethylen-tetralone,-indandione und-indanone Beiträge zur Chemie der Enaminoketone, 6. Mitt

Zusammenfassung Die Synthese einer Reihen euer Enaminoketone, welche sich vom Aminomethylen-tetrahydronaphthalinon,-indandion bzw.-indanon ableiten, wird beschrieben. Diese Verbindungen haben die Eigenschaften von pH-Indikatoren und z. T. Farbstoff-charakter. Durch Kondensation mit Amino-pyridinen,-pyrimidinen bzw. Aminopyrazolen werden Naphtho[2,1-c][1,6]-naphthyridine, Benzo[f]pyrimido[4,5-c]isochinoline, Benzo-[h]pyrazolo[2,3-a]chinazoline, Indeno[2,1-c][1,6]naphthyridine bzw. Indeno[1,24,5]pyrido[2,3-d]pyrimidine erhalten.

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Enaminoketones, VI: N-substituted aminomethylene-tetralones,-indandiones and-indanones

The syntheses of aminomethylene-tetrahydronaphthalinones,-indanediones and-indanones are reported. The properties of these enaminoketones as pH-indicators and dyes are discussed. By condensation with amino-pyridines,-pyrimidines or aminopyrazoles naphtho[2.1-c][1.6]naphthyridines, benzo[f]pyrimido-[4.5-c]isoquinolines, benzo[h]pyrazolo[2.3-a]quinazolines, indeno[2.1-c][1.6]naphthyridines and indeno[1,24.5]pyrido-[2.3-d]pyrimidines, resp., are formed.

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Herrn Dr.Guido Schetty, Ciba-Geigy AG, Basel, zum 60. Geburtstag gewidmet.     

Synthesis of Alkyl and Aryl Substituted Benzo[h]Naphtho[1,2-b][1,6]naphthyridines

The reaction of 4-chloro-2-methylquinolines and 1-naphthylamine under neat conditions yielded 2-methyl-N-(1-naphthyl)quinolin-4-amines. These potential intermediates on reaction with aliphatic and aromatic carboxylic acids yielded the respective 7-alkyl and -aryl substituted benzo[h]naphtho[1,2-b][1,6]naphthyridines. The highly deshielded protons in the final compounds were assigned on the basis of 2D NMR studies.     

Application of directed metalation in synthesis. Part 8: Interesting example of chemoselectivity in the synthesis of thioaurones and hydroxy ketones and a novel anionic ortho-Fries rearrangement used as a tool in the synthesis of thienopyranones and thiafluorenones

Chemoselective synthesis of thioaurones or 3-hydroxy benzo[b]thiophen-2-aryl ketones, 1-hydroxy naphtho[2,1-b]thiophen-2-aryl ketones and chalcones from N,N-diethyl-ortho-methyl sulfanyl aryl amides were described. (Benzo[b]thiophen-2-yl) alkylates and (naphtho[2,1-b]thiophen-2-yl) alkylates undergo a novel anionic ortho-Fries rearrangement leading to (3-hydroxy benzo[b]thiophen-2-yl) and (1-hydroxy naphtho[2,1-b]thiophen-2-yl) alkyl ketones. The hydroxy ketones were used as intermediates in the synthesis of wide range of benzothienopyranones and thiafluorenones.     

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 ).     

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.     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 7. [1]Benzothieno[2,3-c]naphtho[2,1-h]quinoline and [1]benzothieno[2,3-c]naphtho[2,1-h][1,2,4]triazolo[4,3-a]quinoline

The synthesis of two novel polycyclic heterocyclic ring systems via photocyclization is described. These are [1]benzothieno[2,3-c]naphtho[2,1-h]quinoline and [1]benzothieno[2,3-c]naphtho[2,1-h][1,2,4]triazolo[4,3-α]-quinoline. In the ¹H nmr spectrum the proton at position 6 is strongly deshielded in the first ring system while the proton at position 6 in the second ring system is shifted considerably upfield while the proton at position 8 in the second ring system is the most deshielded proton in that ring system. The bay regions in both ring systems are severely congested.