Protoberberines from Reissert-Compounds. Part IX [1]. An Alternative Approach to Dibenzoquinolizine- and Isoquinonaphthyridin-13a-carboxylic Acids, a Novel Synthesis of Alangimarine

Reimann, Eberhard; Grasberger, Fritz

doi:10.1007/s00706-004-0231-5

Cited by 12 publications

(5 citation statements)

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“…MS (ESI): m / z (%) = 286.1 (100) [M + H] + , 308.1 (67) [M + Na] + . The analytical data are in accordance with the literature…”

Section: Methodssupporting

confidence: 81%

“…MS (ESI): m/z (%) = 286.1 (100) [M + H] + , 308.1 (67) [M + Na] + . The analytical data are in accordance with the literature 31 7-(Benzyloxy)-6-methoxy-3,4-dihydroisoquinoline (9). Synthesized according to a modified procedure of Rohloff et al 32 To a suspension of phosphorus pentachloride (3.45 g, 16.5 mmol, 1.1 equiv) in anhydrous toluene (10 mL) is added N-{2-[4-(benzyloxy)-3methoxyphenyl]ethyl}formamide (4.32 g, 15.1 mmol, 1.0 equiv) dissolved in dichloromethane (10 mL) at room temperature.…”

Section: ■ Experimental Sectionsupporting

confidence: 80%

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A Modular Access to (±)-Tubocurine and (±)-Curine - Formal Total Synthesis of Tubocurarine

2017

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Two consecutive Cu-catalyzed Ullmann-type C-O couplings permitted the first successful entry toward the curare alkaloids (±)-tubocurine and (±)-curine. Starting from vanillin, the synthetic sequence comprises 15 linear steps and includes a total of 24 transformations. In addition, the total synthesis of tubocurine represents a formal total synthesis of the famous arrow poison alkaloid tubocurarine.

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“…MS (ESI): m / z (%) = 286.1 (100) [M + H] + , 308.1 (67) [M + Na] + . The analytical data are in accordance with the literature…”

Section: Methodssupporting

confidence: 81%

Section: ■ Experimental Sectionsupporting

confidence: 80%

A Modular Access to (±)-Tubocurine and (±)-Curine - Formal Total Synthesis of Tubocurarine

2017

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“…In the case of 88c and 88d the benzylic ether group is concomitantly cleaved to the phenols 90c and 90d. Finally the carboxylic acids 90 undergo thermal decarboxylation giving a separable mixture of dehydroberbinone 91a and its 13,13a-dihydroproduct berbinone 92 as well as the alkaloids 14,15-dihydroalangimarine 91c, alangimarine 91d and the synthetic 10-aza-2,3-dimethoxy-8-oxoprotoberberine 91b [47] (Scheme 15).…”

Section: Detailed Applicationsmentioning

confidence: 99%

Recent Strategies for the Synthesis of Protoberberines and Protoberberine Type Compounds

Reimann

2009

COC

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The protoberberines are a widespread, important group of isoquinoline alkaloids. Due to the potent pharmacological and other bioactive properties they have achieved an increasing attention in medicinal chemistry and drug research. This article will give a brief structural classification of the protoberberines and related compounds, the biosynthesis, a compilation of new alkaloids isolated during the last decade including source, structure and analytical/spectral data. The main part of the present review is focused on recent synthesis pathways to the title compounds.

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“…1-4 Therefore, the synthesis of fused ring system incorporating isoquinoline moiety is an attractive goal for many authors. [5][6][7][8][9][10][11][12][13][14][15][16][17] Recently, we have been involved in the synthesis and chemistry of several fused isoqinoline derivatives. [18][19][20][21][22][23][24][25][26][27][28][29] In the present paper, we introduce a new and general route to pyrido[2,1-a]isoquinoline containing many reactive sites.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Reactivity of 2-Chloro-3-formylpyrido[2,1-a]isoquinoline Derivative. A Novel Routes to Pyrazolo[3',4':4,5]pyrido[2,1-a]isoquinoline and Isoquinolino[2,1-g][1,6]naphthyridines

Hassaneen¹,

Wardkhan²,

Mohammed³

2012

HETEROCYCLES

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Treatment of 2-hydroxy-9,10-dimethoxy-4-oxo-6,7-dihydro-4Hpyrido[2,1-a]isoquinoline-1-carbonitrile 2 with POCl 3 /DMF gave 2-chloro-3formylpyrido[2,1-a]isoquinoline derivative 3. Compound 3 reacted with hydrazines 5a-d to give the condensation products 6a-d. Cyclization of 6a gave pyrazolo[3',4':4,5]pyrido[2,1-a]isoquinoline derivative 7. Treatment of 3 with ethoxycarbonylmethylenetriphenylphosphorane 10 afforded (E)-ethyl 3-(2chloro-1-cyano-9,10-dimethoxy-4-oxo-6,7-dihydro-4H-pyrido[2,1-a]isoquinolin-3-yl)acrylate 11. Azidation of 11 yielded the corresponding azido compound 12.Reduction of 12 gave the corresponding amino compound 13 which upon cyclization gave the novel tetracyclic product 14. Compound 12 reacted with triphenylphosphine to give phosphorane compound 15, which reacted with phenyl isothiocyanate to give a novel isoquinolino[2,1-g][1,6]naphthyridine derivative 18.Refluxing of 11 with amines 19a-c and thiophenols 22a-d in ethanol produced the corresponding substitution products 20a-c and 23a-d, respectively. Cyclization of 20a afforded isoquinolino[2,1-g][1,6]naphthyridine derivative 21.of the information may be obtained free of charge from The Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (Tel: +44 (0)1223 762911; www: http://www.ccdc.cam.ac.uk).

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Protoberberines from Reissert-Compounds. Part IX [1]. An Alternative Approach to Dibenzoquinolizine- and Isoquinonaphthyridin-13a-carboxylic Acids, a Novel Synthesis of Alangimarine

Cited by 12 publications

References 0 publications

A Modular Access to (±)-Tubocurine and (±)-Curine - Formal Total Synthesis of Tubocurarine

A Modular Access to (±)-Tubocurine and (±)-Curine - Formal Total Synthesis of Tubocurarine

Recent Strategies for the Synthesis of Protoberberines and Protoberberine Type Compounds

Synthesis and Reactivity of 2-Chloro-3-formylpyrido[2,1-a]isoquinoline Derivative. A Novel Routes to Pyrazolo[3',4':4,5]pyrido[2,1-a]isoquinoline and Isoquinolino[2,1-g][1,6]naphthyridines

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