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The decomposition of a 5G radio access network (RAN) accelerates inter-operator infrastructure sharing of the corresponding transport network as well as the centralized deployment of a centralized unit (CU) and distributed unit (DU). We propose an architecture that enables inter-operator infrastructure sharing of 5G xHaul as slices and on-demand creation of xHaul network slices dynamically over multiple network operators that are interconnected and orchestrated with the standardized interface of the Open Networking Foundation (ONF) Transport API (TAPI) and corresponding standard from Metro Ethernet Forum (MEF). Through a proof of concept, we validated the implementation of the architecture in three live network domains for 5G xHaul.

2-Amino-(1-(2-nitrophenylsulfinyl)azulene derivatives were synthesized by the reaction of 2-aminoazulene with 2-nitrobenzenesulfonyl chloride. Crystal structures of these compounds were determined by X-ray diffraction analysis. The sulfur atom derived nosyl group shows unique geometry. Furthermore, a reaction using 4-nitrobenzenesulfonyl chloride is also demonstrated.

Article, TETRAHEDRON LETTERS. 48(26): 4471-4475 (2007)

The cycloaddition reaction of 2-phenylamino-1-azaazulene (I) or the corresponding bromo derivative (VI) with diphenylacetylene (II) under various reaction conditions is studied.

Azaazulene (III) is synthesized either by O-arylation/C—C coupling of compounds (I) and (II) or by title tandem reaction sequence.

6-Chloro-7H-naphth[3,2,1-cd]azulen-7-ones 9a and 10a easily react with some nucleophiles (sodium methoxide, potassium hydrosulfide, and amines) to give the corresponding 6-substituted products. Halogenation of 7H-naphth[3,2,1-cd]azulen-7-ones with N-halosuccinimides occurs at the C-5 position. Grignard reagents add to 7H-naphth[3,2,1-cd]azulen-7-ones at the seven-membered ring and a subsequent dehydrogenation gives 2-, 3- and 4-substituted products; reactive tendency of the positions of 7H-naphth[3,2,1-cd]azulen-7-one toward the reagents was 6 ≫ 3 > 4 > 2, whereas the steric hindrance was (6 >) 4 > 3 > 2. Condensation of 7H-naphth[3,2,1-cd]azulen-7-ones with active methylene compounds in boiling acetic anhydride occurs at the carbonyl group and gives the corresponding 7-methylene-7H-naphth[3,2,1-cd]azulene derivatives. 6-Hydroxy-7H-naphth[3,2,1-cd]azulen-7-one 7 is obtained by the hydrolysis of 6-methoxy-7H-naphth[3,2,1-cd]azulen-7-one 9b with hydrobromic acid, in almost quantitative yield. Compound 7 exists in a tautomeric mixture with 7-hydroxy-6H-naphth[3,2,1-cd]azulen-6-one 8. Methylation of 7 with diazomethane gives 9b and 7-methoxy-6H-naphth[3,2,1-cd]azulen-6-one 18a in 75% and 25% yield, respectively. Chlorination of 7 with thionyl dichloride also gives a pair of isomers, 5,6-dichloro-7H-naphth[3,2,1-cd]azulen-7-one 11b and 5,7-dichloro-6H-naphth[3,2,1-cd]azulen-6-one 18b. A tautomerism between 6-(substituted methyl)-7H-naphth[3,2,1-cd]azulen-7-ones and 7-hydroxy-6H-naphth[3,2,1-cd]azulen-6-ylidenemethylene derivative is also studied.

7H-Naphth[3,2,1-cd]azulen-7-ones are synthesized by the intramolecular Friedel–Crafts cyclization of diethyl 4-phenylazulene-1,3-dicarboxylate derivatives with polyphosphoric acid (PPA). Treatment of 7H-naphth[3,2,1-cd]azulen-7-one with methyl trifluoromethanesulfonate or perchloric acid gives 7-methoxynaphth[3,2,1-cd]azulenium trifluoromethanesulfonate or 7-hydroxynaphth[3,2,1-cd]azulenium perchlorate. Both spectroscopic inspection and molecular orbital calculations for 7-hydroxynaphth[3,2,1-cd]azulenium ion show that the tropylium moiety is a main contributor to the ground state in the resonance structure. The syntheses of 7H-azuleno[1,8-bc]phenanthren-7-ones and 5,7-dihydrodinaphth[3,2,1-cd:1′,2′,3′-ij]azulene-5,7-diones are also described.

Reactions of diethyl azulene-1,3-dicarboxylate (1) and diethyl 2-chloroazulene-1,3-dicarboxylate (11) with Grignard reagents, followed by dehydration with tetrachloro-1,2-benzoquinone, gave 2-, 4,- and 6-substituted addition–oxidation products. Grignards reagents have a tendency to react with 1 at the positions in the order of 2 > 4 > 6, while steric hindrance has a greater influence at the positions in order of 2 > 4 > 6. Reactions of 1 and 11 with phenyllithium and methyllithium gave similar results. On the other hand, on the reaction of diethyl 2-methoxyazulene-1,3-dicarboxylate (15), Grignard reagents attacked preferentially at the methoxy group, and 2-substituted products were obtained. Use of excess molar equivalents of Grignard reagents led to diaryl-substituted products. Reaction of 2-chloro-1-azaazulenes with Grignard reagents also gave similar addition–oxidation products, and reacted at the positions in the order 8 ≫ 4 > 6, whereas reaction of 2-methoxy-1-azaazulene with a Grignard reagent gave 1-azaazulen-2(1H)-one.

2-Alkylamino-1-azaazulenes react with N-phenylbenzylideneamine N-oxide to give pentacyclic 12-alkyl-5-phenyl-12H-11,12,13-triazaazuleno[2,1-b]fl uorene-2-carbaldehydes, novel pericyclic 22π aromatic heterocycles, in one pot.

The iodination of azulene derivatives of type (I) or (VI) and some consecutive reactions are studied.

Reaction of 2-amino-1-azaazulene with phenyl isocyanate gave 3-phenyl-2H-3,4-dihydro-1,3,4a-triazabenz[5,4-a]azulene-2,4-dione. Reactions of 2-alkylamino-1-azaazulenes with aryl isocyanates gave 2-(N-ethyl-N′-arylureido)-1-azaazulenes initially, which rearranged to N-aryl-2-alkylamino-1-azaazulene-3-carboxamides and successive reaction with another molar amount of aryl isocyanate furnished uracil-fuzed 1-azaazulenes. Reaction of 2-piperidino-1-azaazulene with aryl isocyanate gave N-aryl-2-piperidino-1-azaazulene-3-carboxamide. Reaction of 2-(substituted amino)-1-azaazulenes with chlorosulfonyl isocyanate gave 3-cyano- and 3-chloro-2-(substituted amino)-1-azaazulenes.

Products (III), (IV), and (VI) show strong cytotoxic activities, whereas (IX) does not exhibit any positive effects.

Polysilsesquioxane having an ethoxysulfonyl group as a side chain was synthesized to prepare a proton-conductive film composed of a main chain of siloxane. At first, sodium 4-(2-methylallyloxy)benzenesulfonate was chlorinated with thionyl chloride. Next, hydrosilylation with trichlorosilane was carried out in the presence of platinum catalyst followed by treatment with ethanol. Finally, the hydrolytic polycondensation was carried out to provide poly(3-(4-ethoxysulfonylphenoxy)-2-methylpropyl)silsesquioxane. This polysilsesquioxane was heated to form a free-standing film that was brittle and brown in color.

The reaction of ethyl 2-hydrazino-1-azaazulene-3-carboxylate with diphenylcyclopropenone (DPP) gave ethyl (Z)-2-[N′-(3-amino-2,3-diphenylpropenoyl)hydrazino]-1-azaazulene-3-carboxylate, ethyl 8,9-diphenyl-1,2,9b-triazaindeno[1,7,6-bcd]azulene-3-carboxylate, ethyl (E)-3-(1,2-diphenylethyl)-1,2,3a-triazacyclopent[a]azulene-9-carboxylate, and ethyl 2-amino-1-azaazulene-3-carboxylate (8a), together with the products of 8a with DPP. However, the reaction of 2-hydrazino-1-azaazulene with DPP gave 4H-2,3-diphenyl-1,4a-diazabenz[a]azulen-4-one, (Z)-3-[(1-azaazulen-2-yl)amino]-2,3-diphenylpropenamide, 3,4-diphenyl-3,4-dihydro-2H-1,4a-diazabenz[a]azulen-2-one and 2-amino-1-azaazulene. The structures of the obtained products were determined by inspections of their physical and spectral data, as well as single-crystal X-ray structure analyses of some of these compounds. The reaction mechanisms are discussed.

The synthesis of the new title pyrrolobenzodiazepine (IV) is described, which exhibits strong cytotoxic activity against HeLa S3 cells.

Review: synthetic methods and reactions of azaazulenes including some of their dihydro-, oxo-, and hetero-fused derivatives published during 2000 to early in 2010; 79 refs.

Phosphorane derivative (I) undergoes a reaction with arylaldehydes (II) via the corresponding azaazulenylimine intermediates to afford the bis[(azaazulenyl)-amino]arylmethanes (III) in low to moderate yields.

Polyhedral oligomeric silsesquioxane (POSS) polymers were synthesized by the dehydrogenative condensation of (HSiO3/2)8 with water in the presence of diethylhydroxylamine followed by trimethylsilylation. Coating films were prepared by spin-coating of the coating solution prepared by the dehydrogenative condensation of POSS. The hardness of the coating films was evaluated using a pencil-hardness test and was found to increase up to 8H with increases in the curing temperature. Free-standing film and silica gel powder were prepared by aging the coating solution at room temperature. The silica gel powder was subjected to heat treatment under air atmosphere to show a specific surface area of 440 m2 g−1 at 100 °C, which showed a maximum at 400 °C as 550 m2 g−1. Copyright © 2011 John Wiley & Sons, Ltd.

Syntheses and cycloadditions of ethyl 2-(benzylidene)hydrazino-1-azaazulene-3-carboxylates were investigated. Condensations of ethyl 2-hydrazino-1-azaazulene-3-carboxylate with benzaldehyde and p-methoxybenzaldehyde gave corresponding hydrazones in good yields. Reactions of ethyl 2-(benzylidene)hydrazino-1-azaazulene-3-carboxylate (2a) and ethyl 2-(p-methoxybenzylidene)hydrazino-1-azaazulene-3-carboxylate with dimethyl acetylenedicarboxylate gave novel 1 : 2-adducts, 4a,11,11a-triazaindeno[5,6-a]azulene derivatives and 2-methoxycarbonylimino-1-(2-pyrrolylmethyl)-1-azaazulene derivatives as major products. Reaction of 2a with electron deficient olefins (tetracyanoethylene, N-methylmaleimide) gave no cycloadduct but a cyclization product of 2a, 3-phenyl-1,2,3a-triazacyclopent[a]azulene-9-carboxylate. The structures of the obtained compounds were analyzed by inspections of their physical and spectral data, and by single-crystal X-ray analyses of some of these compounds. The reaction mechanisms of these react...

The stability and resonance energy of heterocycle-annulated 1-azaazulenes such as cyclohepta[4,5]pyrrolo[1,2-a]imidazole (5a) and 12-methoxy-5H-cyclohepta[4,5]pyrrolo[2,3-b][1,5]benzodiazepine (7) were elucidated by means of Aihara’s TRE and Gimarc’s TCS rule. These compounds are predicted to be aromatic with positive resonance energies and in conformity with the TCS rule.

Cycloadditions of the title compounds with dimethyl acetylenedicarboxylate gave 1:2-cycloadducts. The structural assignments of the products were deduced by spectral inspections; the structure for one compound was established by X-ray crystallography.

2-Aminoazulene (1a) reacted with dimethyl acetylenedicarboxylate (DMAD) to give dimethyl 1,2-azulenedicarboxylate, tetramethyl 2,2′-(2-amino-1,3-azulenediyl)bis[fumarate], and dimethyl 2-(4-methoxycarbonyl-2-oxo-l,2-dihydroazuleno[2,1-b]pyridin-10-yl)fumarate. The reaction of ethyl 2-amino-1-azulenecarboxylate (1b) with DMAD gave dimethyl 2-(2-amino-3-ethoxycarbonyl-1-azulenyl)fumarate and 10-ethyl 4-methyl 2-oxo-1,2-dihydroazuleno[2,1-b]pyridine-4,10-dicarboxylate (8a). The treatment of 8a with phosphoryl chloride gave the 2-chloroazuleno[2,1-b]pyridine derivative. Reactions of 1a and 1b with methyl propiolate gave corresponding Michael adducts and the azuleno[2,1-b]pyridin-3(4H)-one derivatives. Reactions of 1a and 1b with dibenzoylacetylene gave 4-benzoyl-2-phenylazuleno[2,1-b]pyridine derivatives.

2-Hydrazinocyclohepta[b]pyrrole reacted with dimethyl acetylenedicarboxylate (DMAD) to give the hydrazones (2a), the pyrimidinone-fused cyclohepta[b]pyrrole (3), 1,2,4-triazinone-fused cyclohepta[b]pyrroles, and the 1,2-dihydro-3H-pyrazol-3-one derivative. Thermolysis of 2a gave 3 and tetramethyl pyrrole-2,3,4,5-tetracarboxylate. The reaction of ethyl cyclohepta[b]pyrrole-3-carboxylate with DMAD at room temperature gave the hydrazone and the spiropyrazoline derivative.

We synthesized Schiff bases, ethyl 2-[2-(benzilideneamino)anilino]cyclohepta[b]pyrrole-3-carboxylate (2a) and ethyl 2-[2-(2-butenylideneamino)anilino]cyclohepta[b]pyrrole-3-carboxylate (2b), from ethyl 2-(2-aminoanilino)cyclohepta[b]pyrrole-3-carboxylate (1) in excellent yields by treating 1 with benzaldehyde or 2-butenal in the presence of molecular sieves 4A, respectively. Further, the cyclization and cycloaddition reactions of the Schiff bases were investigated. Treatment of 2a with iron(III) chloride or Pd–C gave ethyl 2-(2-phenylbenzimidazol-1-yl)cyclohepta[b]pyrrole-3-carboxylate and 12H-5,13-dihydrocyclohepta[1′,2′ : 4,5]pyrrolo[2,3-b][1,5]benzodiazepin-12-one (4). A similar treatment of 2b, however, gave ethyl 2-(4-methylqinolin-8-yl)aminocyclohepta[b]pyrrole-3-carboxylate and 4. The reaction of 2a with dimethyl acetylenedicarboxylate (DMAD) gave 15a-ethyl 5,6,7,15-tetramethyl 15,15a-dihydro-14H-pyrrolo[2′,1′ : 1,2]isoquino[3,4-b][1,5]benzodiazepine-5,6,7,15,15a-pentacarboxylate (6) and methyl 4-(...

The reactions of 2- and 8-(substituted amino)-1-azaazulenes with dimethyl acetylenedicarboxylate (DMAD) were investigated. Treatment of ethyl 2-acetylamino-1-azaazulene-3-carboxylate with DMAD in refluxing acetonitrile gave 9-ethyl 1,2,3-trimethyl 3a-azacyclopent[a]azulene-1,2,3,9-tetracarboxylate, 5-ethyl 1,2,2a,3-tetramethyl 4-acetyl-2a,3-dihydro-4H-4, 10b-diazapentaleno[1,6-aj]azulene-1,2,2a,3,5-pentacarboxylate (3a), and dimethyl (10-ethoxycarbonyl-4-methoxycarbonyl-2,4a-dihydro-2-oxo-2H-1,4a-diazabenz[a]azulen-3-yl)maleate. Compound 3a thermally rearranged to 9-ethyl 2,3,10,11-tetramethyl 1-acetyl-2,3,4,4a-tetrahydro-1H-1,4-diaza-3,4a-ethenofluorene-2,3,9,10,11-pentacarboxylate. The reaction of ethyl 2-alkylamino-1-azaazulene-3-carboxylate with DMAD gave the corresponding 4-alkyl-2a,3-dihydro-4H-4,10b-diazapentaleno[1,6-aj]azulene derivatives, and the etheno-bridged 1-azaheptalene derivative. The reaction of 8-ethylamino-3-phenyl-1-azaazulene with DMAD gave trimethyl 1-phenyl-2a-azabenz[cd]azulene-3,...

The stability and resonance energy of heterocycle-annulated 1-azaazulenes such as cyclohepta[4,5]pyrrolo[1,2-a]imidazole (5a) and 12-methoxy-5H-cyclohepta[4,5]pyrrolo[2,3-b][1,5]benzodiazepine (7) were elucidated by means of Aihara’s TRE and Gimarc’s TCS rule. These compounds are predicted to be aromatic with positive resonance energies and in conformity with the TCS rule.

Syntheses and cycloadditions of ethyl 2-(benzylidene)hydrazino-1-azaazulene-3-carboxylates were investigated. Condensations of ethyl 2-hydrazino-1-azaazulene-3-carboxylate with benzaldehyde and p-methoxybenzaldehyde gave corresponding hydrazones in good yields. Reactions of ethyl 2-(benzylidene)hydrazino-1-azaazulene-3-carboxylate (2a) and ethyl 2-(p-methoxybenzylidene)hydrazino-1-azaazulene-3-carboxylate with dimethyl acetylenedicarboxylate gave novel 1 : 2-adducts, 4a,11,11a-triazaindeno[5,6-a]azulene derivatives and 2-methoxycarbonylimino-1-(2-pyrrolylmethyl)-1-azaazulene derivatives as major products. Reaction of 2a with electron deficient olefins (tetracyanoethylene, N-methylmaleimide) gave no cycloadduct but a cyclization product of 2a, 3-phenyl-1,2,3a-triazacyclopent[a]azulene-9-carboxylate. The structures of the obtained compounds were analyzed by inspections of their physical and spectral data, and by single-crystal X-ray analyses of some of these compounds. The reaction mechanisms of these react...

Reaction of 2-amino-1-azaazulene with diphenylcyclopropenone gave 1,2-diphenyl-1,2,3,1Ob-tetrahydro-4, 10b-diazabenz [a] azulen-3-one, which rearranged to N-(1-azaazulen-2-yl)-α-cis-stylbenecarboxamide and N-(1-azaazulen-2-yl)- α -trans-stylbenecarboxamide by heating. Some structures of these products were determined by the X-ray structure analyses. The reaction mechanism is discussed

The reactions of sodium salt of 2-methoxy-1-azaazulene-3-carboxyaldehyde tosylhydrazone with styrenes gave 3,8-cyclohexeno-2-methoxy-1-azaazulenes and 3-cyclopropyl-2-methoxy-1-azaazulenes. The formers were afforded through the diazo compound generated from the tosylhydrazone and the latters were yielded via the carbene derived from the diazo compound. The reactions with stilbenes gave the corresponding cyclopropane derivatives. The similar reactions with sodium salt of azulene-1-carboxaldehyde tosylhydrazone gave the analogous result

The reaction of ethyl 2-hydrazino-1-azaazulene-3-carboxylate with diphenylcyclopropenone (DPP) gave ethyl (Z)-2-[N′-(3-amino-2,3-diphenylpropenoyl)hydrazino]-1-azaazulene-3-carboxylate, ethyl 8,9-diphenyl-1,2,9b-triazaindeno[1,7,6-bcd]azulene-3-carboxylate, ethyl (E)-3-(1,2-diphenylethyl)-1,2,3a-triazacyclopent[a]azulene-9-carboxylate, and ethyl 2-amino-1-azaazulene-3-carboxylate (8a), together with the products of 8a with DPP. However, the reaction of 2-hydrazino-1-azaazulene with DPP gave 4H-2,3-diphenyl-1,4a-diazabenz[a]azulen-4-one, (Z)-3-[(1-azaazulen-2-yl)amino]-2,3-diphenylpropenamide, 3,4-diphenyl-3,4-dihydro-2H-1,4a-diazabenz[a]azulen-2-one and 2-amino-1-azaazulene. The structures of the obtained products were determined by inspections of their physical and spectral data, as well as single-crystal X-ray structure analyses of some of these compounds. The reaction mechanisms are discussed.

Cyclopenta[a]phenalen-9(8H)-one, a keto form of cyclopenta[a]phenalen-9-ol, has been found to be exclusively in an extended phenalenone form.

Reaction of 2-amino-1-azaazulene with phenyl isocyanate gave 3-phenyl-2H-3,4-dihydro-1,3,4a-triazabenz[5,4-a]azulene-2,4-dione. Reactions of 2-alkylamino-1-azaazulenes with aryl isocyanates gave 2-(N-ethyl-N′-arylureido)-1-azaazulenes initially, which rearranged to N-aryl-2-alkylamino-1-azaazulene-3-carboxamides and successive reaction with another molar amount of aryl isocyanate furnished uracil-fuzed 1-azaazulenes. Reaction of 2-piperidino-1-azaazulene with aryl isocyanate gave N-aryl-2-piperidino-1-azaazulene-3-carboxamide. Reaction of 2-(substituted amino)-1-azaazulenes with chlorosulfonyl isocyanate gave 3-cyano- and 3-chloro-2-(substituted amino)-1-azaazulenes.

Chloro- and phenyl-ketene react with 2-amino-1-azaazulene 1 to give 4,4a-dihydro-1,4a-diazacyclopent[a]azulen-4-one derivatives 2a and 2b as cycloadducts. With 2-alkylamino-1-azaazulenes 4 chloroketene reacts to give anhydro-3-hydroxy-1,3a-diazacyclopent[a]azulenium hydroxide derivatives 5, whereas phenylketene gives 1-alkyl-4-benzyl-4-hydroxy-1,2,3,4-tetrahydro-1,10-diazabenz[a]azulen-2-ones 6, 2-alkylamino-3-phenylacetyl-1-azaazulenes 7 and 1-alkyl-4-benzyl-1,2-dihydro-1,10-diazabenz[a]azulen-2-ones 8. The structures of compounds 5a, 6a and 8a are deduced by X-ray structural analysis. These reactions are interpreted in the terms of the hard-soft-acid-base principle.

8-(Diethylborylmethylamino)-3-phenyl-1-azaazulene (5) has been synthesized, in which the 8-methylamino-azaazulene moiety is found to act as a bidentate ligand whose two boron–nitrogen bond lengths are almost equivalent.

Amination of azaazulenes 1–3 with O-mesitylsulfonylhydroxylamine occurs at N-1 and gives the corresponding azaazulenium salts 4–6. The treatment of the salts 4 and 6 with potassium carbonate gives 1-amino-2-imino-1,2-dihydro-1,3-diaza- and 1-azaazulenes. The structure of 1-amino-2-ethylimino-1,2-dihydro-1-azaazulene (10) was characterized by X-ray crystal structure analysis. Reaction of the salt 4 with acetic anhydride gave 2-methyl-1,3,3a,9-tetraazacyclopent[a]azulene. The reaction of the salts 4 and 5 with diethyl ethoxymethylenedicarboxylate (DEEM) in the presence of potassium carbonate in acetonitrile gave 1,3,3a,9-tetraaza- (19) and 1,3,3a-triazacyclopent[a]azulene derivatives (21) as major products, whereas the reaction in ethanol gave 1,2a,3-triaza- (17) and 2a,3-diazabenz[cd]azulene derivatives (22), respectively. Similar treatment of 6 with DEEM gave diethyl (2-ethylimino-1,2-dihydro-1-azaazulen-1-yl)aminomethylenemalonate 23, which converted to 2a,3-diazabenz[cd]azulene derivative (24). The salts 4–6 reacted with active methylene compounds such as diethyl acetonedicarboxylate, diethyl oxalacetate and ethyl pyruvate, at the N-amino group followed by a cyclization at the C-8 position on the azaazulene ring to give 1,2a,3-triaza- (25, 28, 29) and 2a,3-diazabenz[cd]azulene derivatives (26, 27, 30). Cycloaddition of the salts 4–6 with acetylenic esters in the presence of potassium carbonate proceeded regioselectively and gave 1,2a,3-triaza- (32–35) or 2a,3-diazabenz[cd]azulene derivatives (31, 36, 37, 39–41).

Formerly-proposed structures, thiazolo[3,2-a][1,5]benzodiazepine and [1,4]diazepino[7,1-b]benzothiazole derivatives, cycloadducts from the reactions of thiazolo[3,2-a]benzimidazole and imidazo[2,1-b]benzothiazole derivatives with propiolic esters, are revised to methyl 2-[4-methyl-(E)-1H-[1,4]thiazino[4,3-a]benzimidazol-1-ylidene)methoxycarbonylmethyl]-(E)-acrylate and methyl [2-methyl-(E)-10H-imidazo[2,1-c][1,4]benzothiazine-10-ylidene)-methoxycarbonylmethyl]-(E)-acrylate, respectively, whose structures are deduced by X-ray structure analysis.

Aldol condensation of 2,3-diformyl-1-azaazulene with acetone, methoxyacetone, and benzylacetone in aq. NaOH solution gave corresponding 11-azacyclohept[α]azulen-3(3H)-one (2a), 2-methoxy-derivative (2b) and 2-benzyl-derivative (2d) in good yields. Hydrolysis of 2b using hot HBr gave 2-hydroxy-11-azacyclohept[a]azulen-3(3H)-one (2f). Acetylation of 2f gave 2-acetoxy-11-azacyclohept[α]azulen-3(3H)-one (2g). Reaction of the compounds (2a, 2b, 2f) with diethyl malonate in Ac 2 O under heating gave 1,9(11bH)-11b-azaazuleno[1,2,3-cd]azulenedione derivatives (4a, 4b, 4f). Compounds (2b, 2f) showed weak cytotoxic activity against HeLa S3 cells.

6-Chloro-7H-naphth[3,2,1-cd]azulen-7-ones 9a and 10a easily react with some nucleophiles (sodium methoxide, potassium hydrosulfide, and amines) to give the corresponding 6-substituted products. Halogenation of 7H-naphth[3,2,1-cd]azulen-7-ones with N-halosuccinimides occurs at the C-5 position. Grignard reagents add to 7H-naphth[3,2,1-cd]azulen-7-ones at the seven-membered ring and a subsequent dehydrogenation gives 2-, 3- and 4-substituted products; reactive tendency of the positions of 7H-naphth[3,2,1-cd]azulen-7-one toward the reagents was 6 ≫ 3 > 4 > 2, whereas the steric hindrance was (6 >) 4 > 3 > 2. Condensation of 7H-naphth[3,2,1-cd]azulen-7-ones with active methylene compounds in boiling acetic anhydride occurs at the carbonyl group and gives the corresponding 7-methylene-7H-naphth[3,2,1-cd]azulene derivatives. 6-Hydroxy-7H-naphth[3,2,1-cd]azulen-7-one 7 is obtained by the hydrolysis of 6-methoxy-7H-naphth[3,2,1-cd]azulen-7-one 9b with hydrobromic acid, in almost quantitative yield. Compound 7 exists in a tautomeric mixture with 7-hydroxy-6H-naphth[3,2,1-cd]azulen-6-one 8. Methylation of 7 with diazomethane gives 9b and 7-methoxy-6H-naphth[3,2,1-cd]azulen-6-one 18a in 75% and 25% yield, respectively. Chlorination of 7 with thionyl dichloride also gives a pair of isomers, 5,6-dichloro-7H-naphth[3,2,1-cd]azulen-7-one 11b and 5,7-dichloro-6H-naphth[3,2,1-cd]azulen-6-one 18b. A tautomerism between 6-(substituted methyl)-7H-naphth[3,2,1-cd]azulen-7-ones and 7-hydroxy-6H-naphth[3,2,1-cd]azulen-6-ylidenemethylene derivative is also studied.

7H-Naphth[3,2,1-cd]azulen-7-ones are synthesized by the intramolecular Friedel–Crafts cyclization of diethyl 4-phenylazulene-1,3-dicarboxylate derivatives with polyphosphoric acid (PPA). Treatment of 7H-naphth[3,2,1-cd]azulen-7-one with methyl trifluoromethanesulfonate or perchloric acid gives 7-methoxynaphth[3,2,1-cd]azulenium trifluoromethanesulfonate or 7-hydroxynaphth[3,2,1-cd]azulenium perchlorate. Both spectroscopic inspection and molecular orbital calculations for 7-hydroxynaphth[3,2,1-cd]azulenium ion show that the tropylium moiety is a main contributor to the ground state in the resonance structure. The syntheses of 7H-azuleno[1,8-bc]phenanthren-7-ones and 5,7-dihydrodinaphth[3,2,1-cd:1′,2′,3′-ij]azulene-5,7-diones are also described.

The reaction of 2-chloro-1-azaazulene (1a) with the benzyne prepared from (phenyl)[o-(trimethylsilyl)phenyl]iodonium triflate with tetrabutylammonium fluoride gave 1-phenyl-1-azaazulen-2(1H)-one and 8-[2-(2-chloro-1-azaazulen-6-yl)phenyl]-1-azaazulen-2(1H)-one (5), whereas the reaction of 1a with the benzyne prepared from benzenediazonium-2-carboxylate gave 6,10b-etheno-1-azabenz[e]azulen-2(3H)-one (11) together with 12.

Ethyl (2-alkylimino-1,2-dihydro-1-azaazulen-1-yl)acetates (3) were synthesized from 2-alkylamino-1-ethoxycarbonylmethyl-1-azaazulenium salts, which were produced from 2-alkylamino-1-azaazulenes with ethyl bromoacetate. Reaction of 3 with acid anhydrides gave the mesoionic anhydro-3-acyl-1-alkyl-2-hydroxy-1,3a-diazacyclopent[a]azulenium hydroxide. Polar cycloaddition of 3 with methyl propiolate gave methyl 2-alkyl-1-oxo-1,2-dihydro-2,9b-diazaindeno[3,3a,4,5-bcd]azulene-8-carboxylate and 3-ethyl 5-methyl 2-alkylamino-2a-azabenz[cd]azulene-3,5-dicarboxylate.