Synthesis of [1,2,4]triazolo[3,4-a]isoquinolines and pyrrolo[2,1-a]isoquinolines using α-keto hydrazonoyl halides

Elwan, Nehal M.; Abdelhadi, Hyam A.; Abdallah, Tayseer A.; Hassaneen, Hamdi M.

doi:10.1016/0040-4020(96)00024-5

Cited by 72 publications

(28 citation statements)

References 7 publications

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“…± Fused isoquinoline derivatives compose a very interesting class of compounds because of their significant biological and pharmaceutical activities [1 ± 3]. As part of our studies aimed at developing simple and efficient syntheses of polyfunctional heteroaromatics from readily obtained starting materials, we have previously reported the synthesis of triazoloisoquinolines and pyrroloisoquinolines from 3,4-dihydroisoquinolines and hydrazonoyl halides [4] [5]. However, in many cases, the exact structure of the reaction products could not be established unequivocally, because several closely similar isomeric products could be formed (cf.…”

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confidence: 99%

Synthesis and Reactivity of 2-(6,7-Diethoxy-3,4-dihydroisoquinolin- 1-yl)acetonitrile towards Hydrazonoyl Halides

Awad

Elwan

Hassaneen

et al. 2001

HCA

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The synthesis of 2-(6,7-diethoxy-3,4-dihydroisoquinolin-1-yl)acetonitrile (1) has been performed by ring closure of the corresponding amide according to the Bischler-Napieralski method (Scheme 1). Based on spectroscopic data, the tautomeric 2-(tetrahydroisoquinolin-1-ylidene)acetonitrile is the actual compound. The reactions of 1 with a-oxohydrazonoyl halides 4 in the presence of Et 3 N led to 2-(aryldiazenyl)pyrrolo[2,1-a]-isoquinoline derivatives 8 (Scheme 2), whereas with C-(ethoxycarbonyl)hydrazonoyl chlorides 14, 2-(arylhydrazono)pyrrolo[2,1-a]isoquinoline-1-carbonitriles 16 were formed (Scheme 4). The structures of the products were established from their analytical and spectroscopic data and, in the case of 8b, by X-ray crystallography.

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confidence: 99%

Synthesis and Reactivity of 2-(6,7-Diethoxy-3,4-dihydroisoquinolin- 1-yl)acetonitrile towards Hydrazonoyl Halides

Awad

Elwan

Hassaneen

et al. 2001

HCA

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“…Therefore, the synthesis of this ring system is an attractive goal. We have previously reported the syntheses of triazoloisoquinoline and fused isoquinoline compounds via reaction of 3,4-dihydro-6,7-dimethoxyisoquinoline derivatives with hydrazonoyl halides in chloroform in the presence of triethylamine or in pyridine as catalyst and solvent [8][9][10][11][12]. The aim of the present study is to introduce a new synthetic method by replacing triethylamine in chloroform by the ecologically more acceptable catalyst chitosan [13,14] and under microwave irradiation to enhance reaction rates [15][16][17][18][19] for the synthesis of [1,2,4]triazolo [3,4-a]isoquinolines which were found to be useful precursors for the synthesis of new enaminones 7.…”

Section: Introductionmentioning

confidence: 99%

Reactivity of 1-methylisoquinoline synthesis of pyrazolyl triazoloisoquinoline and thia-diazolyl isoquinoline derivatives

Hassaneen¹,

Mohammed²

2011

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The reaction of 1-methylisoquinoline 1 with hydrazonoyl halides 2 in ethanol in the presence of chitosan under microwave irradiation affords triazoloisoquinoline 4. Product 4 reacts with dimethylformamide-dimethylacetal to give enaminones 7 which react with hydrazonoyl halides to give pyrazolyl triazoloisoquinoline 13. Also, 1-methylisoquinoline 1 reacts with arylisothiocyanate to give thioanilide 15 which reacts with hydrazonoyl halides to give the corresponding thiadiazolyl isoquinoline derivatives 20, 24.

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“…Thus, it was of interest to synthesize ring systems combining the isoquinoline, pyridine, pyrimidine and triazole moieties in order of their possible biological properties. Although several examples of the triazoloazines have been reported in literature (Elnagdi et al, 1990;Quiroga et al, 1999;Elwan et al, 1996;Hassaneen et al, 2001) there is only our previous report contains 1,2,4-triazole ring fused with pyrimidopyridoisoquinoline ring system (Abdallah et al, 2009). In continuation of our previous work on isoquinoline, the present study was designed to synthesis some new derivatives of tri-, tetra-and pentaortho-fused heterocyclic compounds especially pyridoisoquinoline, pyrimidopyridoisoquinoline and triazolo/triazinopyrimidopyridoisoquinoline.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of New Derivatives of Heterocyclic Compounds Containing Pyridine, Pyrimidine and Triazole Ortho-Fused to Isoquinoline Moiety

Abunada¹,

Hassaneen²,

Miqdad³

2012

IJC

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Abstract4-Amino-9,10-dimethoxy-2-phenyl-6,7-dihydro-2(H)-pyrido[2,1-a]isoquinoline-1,3-dicarbonitrile derivatives 4a-c were obtained from the reaction of 6,7-dimethoxy-3,4-dihydroisoqinoline-1-acetonitrile 1 with arylidenemalononitrile 2a-c in boiling acetonitile in the presence of piperidine. The reaction of 4a-c with triethyl orthoformate in acetic anhydride at reflux give the ethoxymethyleneamino derivatives 5a-c. Compounds 5a-c were reacted with hydrazine hydrate and give the corresponding 4-amino-3-imino-2-aryl-3,4,8,9-tetrahydro-2(H)-pyrimido[5′,4′:5,6] pyrido [2,1-a]isoquinoline-1-carbonitrile derivatives 6a-c. Refluxing compound 6a in an excess of triethyl orthoformate give 7a. When compounds 6a-c were refluxed with acetic anhydride or benzoyl chloride in pyridine, they afford the corresponding 4-methyl and 4-phenyl derivatives 8a-c and 9a-c, respectively. Compound 6a was refluxed in diethyloxalate and give product 10. Also, the reaction of 6a with C-acylhydrazonoyl halides 13a,b in refluxing chloroform in the presence of triethylamine afford 14a,b. Correct elemental analyses and spectral data (IR, 1 H NMR, 13 C NMR and MS) confirm the structure of the synthesized compounds.

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Synthesis of [1,2,4]triazolo[3,4-a]isoquinolines and pyrrolo[2,1-a]isoquinolines using α-keto hydrazonoyl halides

Cited by 72 publications

References 7 publications

Synthesis and Reactivity of 2-(6,7-Diethoxy-3,4-dihydroisoquinolin- 1-yl)acetonitrile towards Hydrazonoyl Halides

Synthesis and Reactivity of 2-(6,7-Diethoxy-3,4-dihydroisoquinolin- 1-yl)acetonitrile towards Hydrazonoyl Halides

Reactivity of 1-methylisoquinoline synthesis of pyrazolyl triazoloisoquinoline and thia-diazolyl isoquinoline derivatives

Synthesis of New Derivatives of Heterocyclic Compounds Containing Pyridine, Pyrimidine and Triazole Ortho-Fused to Isoquinoline Moiety

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