Heteroelectrocyclic reaction of 4‐azido‐3‐hydrazonoalkyl‐quinolines to 2‐arylaminopyrazolo[4,3‐<i>c</i>]quinolones

Hojas, Gerhard; Fiala, Werner; Stadlbauer, W.

doi:10.1002/jhet.5570370625

Cited by 20 publications

(7 citation statements)

References 14 publications

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“…27 Therefore, we investigated the thermal cyclization of 3-azidothienoquinolines 6a-e, with the hope of obtaining the interesting tetracyclic ring systems 7a-e. Thus, refluxing azido compounds 6a-e in bromobenzene for one hour afforded the hitherto unknown isoxazolo[3`,4`:4,5]thieno[2,3-c]quinolines 7a-e, in good yields (the reaction may be monitored by the evolution of nitrogen or by disappearance of the intense azide absorption at 2120-2140 cm -1 in the IR spectra).…”

Section: Resultsmentioning

confidence: 99%

Fused quinoline heterocycles VII: synthesis of new isoxazolo[3',4':4,5]pyrrolo(or thieno)[2,3-c]quinoline ring systems

Hameed¹,

Sadek²,

Mekheimer³

2008

Arkivoc

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Abstract3-Amino-4-chlorothieno(or pyrrolo)[3,2-c]quinoline-2-carboxylates 3a,b react with alkylamines 4a-g to give the corresponding 4-alkylaminothieno(or pyrrolo)[3,2-c]quinoline-2-carboxylates 5a-g. Diazotization of 5a-g, followed by reaction with NaN 3 , leads to the formation of 3-azido-4-alkylaminothieno(or pyrrolo)[3,2-c]quinoline-2-carboxylates 6a-g, a new heterocyclic ring system. Thermolysis of azido compounds 6a-g in bromobenzene at reflux temperature afforded the novel tetracyclic ring system isoxazolo

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Section: Resultsmentioning

confidence: 99%

Fused quinoline heterocycles VII: synthesis of new isoxazolo[3',4':4,5]pyrrolo(or thieno)[2,3-c]quinoline ring systems

Hameed¹,

Sadek²,

Mekheimer³

2008

Arkivoc

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“…Organic azides with suitable ortho substituents are known to undergo thermal cyclization with loss of N 2 gas. 17,26,27 Ring closure to the fused furoxan 5 was achieved by thermolysis of the azide 4 in refluxing nitrobenzene (Scheme 2). The IR spectrum of furoxan 5 showed characteristic absorption bands at 1448 cm -1 assigned to the C=N-O, while the stretching vibration of the fragment O-N→O was seen at 1301 cm -1 (as the recently reported for furoxan ring 28 ).…”

Section: Resultsmentioning

confidence: 99%

Nucleophilic substitution and ring transformation reactions with 4-chloro-6-ethyl-3-nitropyrano[3,2-c]quinoline-2,5(6H)-dione

Hassnin¹

2012

Arkivoc

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4-Chloro-6-ethyl-3-nitropyrano[3,2-c]quinoline-2,5(6H)-dione (3) was obtained by nitration followed by chlorination of 4-hydroxypyranoquinoline-2,5-dione 1. Substitution reactions of compound 3 with various nucleophiles, namely: sodium azide, amines, thiophenol and malononitrile, led to a series of novel 4-sustituted-3-nitropyranoquinolinones. Also, nucleophilic reactions of compound 3 with hydrazine, cyanoguanidine and S-methylisothiourea, involving ring opening-ring closure of the pyranoquinolinedione nucleus, are described.

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“…This fact was surprising for us because we could recently show that analogous heterocyclic 1-acyl-2-azido compounds such as 3-acetyl-4-azido-2(1H)-quinolones react easily to 4-azido-3-hydrazonoalkylquinolines. These hydrazones gave upon thermolysis the desired 2 -a r y l a m i n o p y r a z o l o [ 4 , 3 -c] q u i n o l i n -4 ( 5H)-ones [11 ] . This fact prompted us to transform the reaction sequence investigated in ref.…”

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confidence: 99%

Synthesis of 10‐Aryl‐10H‐naphtho[1,8a,8‐fg]indazol‐7‐ones

Stadlbauer

Hojas

2003

Journal of Heterocyclic Chem

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Dedicated to Professor Thomas Kappe on the occasion of his 70th birthday3 -H y d r o x y -2 -[ 1 -( a r y l h y d r a z o n o ) e t h y l ] -1H-phenalen-1-ones 3, obtained from 2-acetyl-3-hydroxy-1H-phenalen-1-one (1) and arylhydrazines 2, cyclize under acidic conditions to 8-methyl-10-aryl-10H-naphtho-[1,8a,8-fg]indazol-7-ones 4. Indazoles 4 are also obtained from 2-acetyl-3-hydroxy-1H-phenalen-1-one (1) and arylhydrazines 2 in a one-pot reaction. 2-Acetyl-3-azido-1H-phenalen-1-one (6) does not give 8-methyl-9-arylamino-9H-naphtho [1,8a,8-fg]indazol-7-ones via azide decomposition but gives again by nucleophilic replacement of the azide moiety in 6 the indazole 4. J. Heterocyclic Chem., 40, 753(2003).Indazole derivatives are of great interest because of their pharmaceutical activity, use in agrochemistry, in dye chemistry and in photographic processes [2]. Whereas the basic ring system of indazole is investigated thoroughly, polyfused derivatives are rarely described. In the course of our investigations of ring closure reactions of phenalene derivatives [3-5] we focused our interest on the synthesis of indazoles of type A (typus of a 1H-indazole) and of type B (typus of a 2H-indazole). In the literature, only one example of such an indazole of type A is described as a follow-up product in the ring enlargement of acenaphthenequinone [6]. Scheme 1We started our synthesis program with a 2-acyl-1-hydrazinoarene synthon, which should give in the cyclization step the formation of one new N-C bond. As the first step in this reaction the hydrazinolysis of 2-acetyl-3-hydroxy-1H-phenalen-1-one (1) was planned. 2-Acetyl-3-hydroxy-1H-phenalen-1-one (1) was obtained in a 2-step reaction from phenalene-1,3-dione by cyclocondensation with diethyl malonate, followed by a ring-opening reaction in sodium hydroxide solution and subsequent spontaneous decarboxylation upon acidification as described recently [5]. Attempts to obtain 2-acetyl-3-hydroxy-1H-phenalen-1-one (1) in a one step reaction by direct acetylation of phenalene-1,3-dione using acetic acid with acid catalysts as described in several heterocyclic systems [7] was not successful.The reaction of 2-acetyl-3-hydroxy-1H-phenalen-1-one (1) with arylhydrazines 2 was performed either in dimethylformamide without catalyst in the case of phenylhydrazine (2a) or with glacial acetic acid and sulfuric acid as catalyst in the case of 4-nitrophenylhydrazine (2b). In both cases 3-hydroxy-2-[1-(arylhydrazono)ethyl]-1H-phenalen-1-ones 3 were obtained in 48 and 97% yield, respectively.Because of the high reactivity of 3a, in all experiments, traces of the follow-up ring closed compound 4 a w e r e

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Heteroelectrocyclic reaction of 4‐azido‐3‐hydrazonoalkyl‐quinolines to 2‐arylaminopyrazolo[4,3‐c]quinolones

Cited by 20 publications

References 14 publications

Fused quinoline heterocycles VII: synthesis of new isoxazolo[3',4':4,5]pyrrolo(or thieno)[2,3-c]quinoline ring systems

Fused quinoline heterocycles VII: synthesis of new isoxazolo[3',4':4,5]pyrrolo(or thieno)[2,3-c]quinoline ring systems

Nucleophilic substitution and ring transformation reactions with 4-chloro-6-ethyl-3-nitropyrano[3,2-c]quinoline-2,5(6H)-dione

Synthesis of 10‐Aryl‐10H‐naphtho[1,8a,8‐fg]indazol‐7‐ones

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