A convenient approach to the synthesis of prenyl-, furo- and pyrano-quinoline alkaloids of the rutaceae

Shobana, N.; Yeshoda, P.; Shanmugam, P.

doi:10.1016/0040-4020(89)80106-1

Cited by 29 publications

(15 citation statements)

References 12 publications

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“…4‐Hydroxy‐6‐methoxy‐2‐quinolone ( 4 ) serves as starting compound for the planned multistep syntheses of the desired fluorescent 4‐cyano‐6‐methoxycarbostyrils. In the literature, several syntheses for quinolone 4 are published, starting from p ‐anisidine ( 1 ) that cyclized to the quinoline nucleus either with diethylmalonate , malonic acid , or Meldrum's acid ; another approach to 4 was reported starting from 5‐methoxy‐nitrobenzoyl chloride and diethyl malonate followed by reduction . Our approach started from p ‐anisidine ( 1 ) and malonic acid ( 2 ) using phosphoryl chloride as cyclization agent similar as described in Refs.…”

Section: Resultsmentioning

confidence: 99%

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6‐Methoxy‐2‐oxo‐1,2‐dihydroquinoline‐3,4‐dicarbonitriles, A Red Compound Class with Solvent and pH Independent Green Fluorescence Maxima

Enoua

Lahm

Uray

et al. 2013

Journal of Heterocyclic Chem

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Section: Resultsmentioning

confidence: 99%

“…The yield was 9.21 g (19%), gray prisms, mp 228–231 °C (acetic acid/methanol), lit. mp 226–240 °C [6a,7,21]. IR (KBr): 3435 m, 1655 w, 1620 s, 1588 s cm 1 .…”

Section: Methodsmentioning

confidence: 99%

6‐Methoxy‐2‐oxo‐1,2‐dihydroquinoline‐3,4‐dicarbonitriles, A Red Compound Class with Solvent and pH Independent Green Fluorescence Maxima

Enoua

Lahm

Uray

et al. 2013

Journal of Heterocyclic Chem

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“…It is of relevance to note that the diprenylquinolinone (4 b) used here is not hitherto reported, which was prepared by treating the 3b with prenyl brom ide in 1 N sodium hydroxide. The interm ediate 4 b on partial deprenylation using so dium hydrogen telluride [13] yielded 5 b.…”

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confidence: 99%

“…Several reports have appeared in the literature for the synthesis of 1 [3,[5][6][7][8][9] and 2 [10][11][12], but the yields of 1 and 2 in these attem pts were not quite appreciable and are often attended by the form ation of their isomeric products. In this com m unication, we wish to present an al ternative but elegant methodology for deriving the titled alkaloids from 5, which in turn was prepared [13] from 4-hydroxyquinolin-2(l H)one 3. Reac tion of 5 a with iodine, in the presence of silver ace tate in glacial acetic acid at room tem perature gave a single product (m .p.…”

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confidence: 99%

Quinoline Alkaloids. Synthesis of Khaplofoline, Ribalinine, and Flindersine

Subramanian

Mohan

Shanmugam

et al. 1992

Zeitschrift Für Naturforschung B

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Reaction o f 4-hydroxy-3-prenylquinolin-2(l H)one (5 a) with iodine and silver acetate gave a iodopyranoquinoline (6 a), which was then converted into the alkaloids khaplofoline (1) and ribalinine (2). Reaction o f 5 a with iodine and mercuric oxide afforded a mixture o f 6a and its angular isomer 7 a; the coversion o f latter into flindersine (10) is described.Pyranoquinoline alkaloids, which possess inter esting pharmacological properties are known [1,2] to occur in the plant family Rutaceae. The alka loids, khaplofoline (1) and ribalinine (2), isolated respectively from Haplophyllum foliosum (Vved) [3] and Balfourodendron riedelianum [4], members of the rutaceae, are structurally proven to be of pyrano [2,3-b]quinoline systems. Several reports have appeared in the literature for the synthesis of 1 [3,5-9] and 2 [10-12], but the yields of 1 and 2 in these attem pts were not quite appreciable and are often attended by the form ation of their isomeric products. 0 R2 1: R1 = R2 = H 2 : R1 = CH3; R2 = OH I R1In this com m unication, we wish to present an al ternative but elegant methodology for deriving the titled alkaloids from 5, which in turn was prepared [13] from 4-hydroxyquinolin-2(l H)one 3. Reac tion of 5 a with iodine, in the presence of silver ace tate in glacial acetic acid at room tem perature gave a single product (m .p. 176-177 °C) in 80% yield. It was identified to be 3-iodo-3,4-dihydro-5-oxo-2,2-dimethyl-2H-pyrano[2,3-b]quionoline (6a). In its IR spectrum two bands at 3420 cm " 1 and 1620 cm -1 were ascribable to a N H stretching and a 4-quinolinone [14] moiety respectively. In its 'H N M R spectrum; the six proton singlet at S 1.58 ppm was characteristic of a gem-dimethyl group, two double doublets with J = 17.4 and 6.6 Hz and * Reprint requests to Dr. K. J. Rajendra Prasad.Verlag der Zeitschrift für Naturforschung. D-W -7400 Tübingen 0 9 3 2 -0 7 7 6 /9 2 /0 7 0 0 -1 0 1 6 /$ 01.00/0 a single proton triplet at S 4.68 ppm were ascriba ble to methylene and methine protons forming ABX system and a singlet at ö 11.83 ppm assigna ble to N H proton. The molecular ion peak (M +) at mle: 355 (55%) in its mass spectrum and elemental analysis C 47.30, H 4.05 and I 35.80% are well agreed to the molecular formula C 14H 14N 0 2I. Thus we realized the preparation of iodopyrano quinoline in high yield and it has proven to be a utility in heterocyclic synthesis. 6 a on alkaline hy drolysis using 0. 1% aqueous sodium hydroxide yielded 3-hydroxykhaplofoline (8); which on heat ing with methyl iodide furnished the alkaloid ribal inine 2 [4] in 90% yield. W ith the view to adducing further attestation of the iodopyranoquinoline structure assigned for the product 6 a, it was dehydroiodinated by refluxing in pyridine to chromenoquinoline 9. F urther reduction of 9 with H 2, P d -C (5 )% gave the alkaloid khaplofoline (1), which was confirmed with authentic sample [3] (m.p. CoTLC, undepressed m.m.p., superimposable IR spectra) (Scheme 1).Similar treatm ent when extended to 6-methyl-4-hydroxy-3-prenylquinolin-2(l H)one (5...

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“…They have interesting pharmacological activities like antihistamine, antibiotic, CNS, anti cancer, antiinflam m atory and antimicrobial prop erties [1][2][3][4][5][6][7][8][9][10][11][12][13]. An extensive survey of the literature showed that a variety of routes had been devel oped for the preparation of quinoline derivatives [14,15].…”

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A Facile Synthesis of Naphthyl-Quinolyl Ethanes and Chromenyl-Quinolyl Ethanes

Sekar

Prasad

1999

Zeitschrift Für Naturforschung B

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2,4-Dihydroxyquinoline, 1-Tetralone, Chromanone, 2,4-D ichloro-3-[l'-(l-chloro-naphth-2-yl)ethyl]quinoline, 2,4-D ichloro-3-[l'-(4-chloro-2-methyl-chromen-3-y 1 )ethyl]quinolineThe reaction of alkaline 2,4-dihydroxyquinoline 1 and 1-tetralone 2 in 2% sodium hydrox ide solution with vinyl acetate afforded a brown solid 3, which on treatment with phospho rous oxychloride yielded 2,4-dichloro-3-[l'-(l-chloro-naphth-2-yl)ethyl]quinoline (4). The same reaction of 1 and chromanone 7 with vinyl acetate afforded 2,4-dichloro-3-[l'-(4-chloro-2-m ethyl-chromen-3-yl)ethyl]quinoline (9).Quinoline derivatives occur quite frequently in Nature. They have interesting pharmacological activities like antihistamine, antibiotic, CNS, anti cancer, antiinflam m atory and antimicrobial prop erties [1][2][3][4][5][6][7][8][9][10][11][12][13]. An extensive survey of the literature showed that a variety of routes had been devel oped for the preparation of quinoline derivatives [14,15]. We wish to report the vinylation reaction technique to the mixture of 1 -tetralone or chro manone with 2,4-dihydroxyquinoline for the pro ductive synthesis of hitherto unknown quinoline derivatives.The reaction of alkaline 2,4-dihydroxyquinoline (la) and 1 -tetralone (2) with vinyl acetate at room tem perature yielded a brown solid. It was insolu ble in all solvents. On treatm ent with POCl3 it af forded a single product 4, melting at 125-126 °C. The IR-spectrum of 4 docum ented the presence of a C=C absorption in the 1600 cm -1 region. The 'H NM R spectrum in CDC13 showed a three proton doublet at 6 1.75, assigned to methyl protons with J = 9.0 Hz, one proton quartet centered at d 5.10, assigned to a m ethine proton adjacent to methyl protons with J = 9.0 Hz. A ten proton aromatic portion appeared at d 7.25-8.30 ppm. The em er gence of molecular ion peak at m/e 385 (M+) and the micro analysis C, 65.48%; H, 3.68% and N, 3.62% were consistent with the molecular formula C2 iH 14N Cl3. On the basis of analytical and * Reprint requests to Dr. K. J. Rajendra Prasad.Fax: 091-422-422387. E-mail: Chemist@bharathi.ernet.in spectral values, the structure 4 was proposed for the compound and named as 2,4-dichloro-3-[l'-(lchloro-naphth-2-yl)ethyl]quinoline (4a) (Scheme). The above reaction might proceed by condensa tion of vinyl acetate with 2,4-dihydroxy-quinoline (1 ) with the concomitant loss of acetic acid to yield the transient 4-hydroxy-3-vinylquinoline 5a. A n other possibility would be condensation of 2,4-dihydroxyquinoline (1 ) with acetaldehyde (formed by hydrolysis of vinyl acetate) affording 5b di rectly. The carbanionic Michael type addition of pre-existing 1-tetralone to isomeric 5b might af ford product 3. Finally, compound 3, on treatm ent with POCI3, could yield the corresponding chloro derivative 4 (Scheme).The same reaction was extended to an other de rivative of 2,4-dihydroxy quinoline (lb ) with 1-tetralone to yield derivative 4b (Scheme).The same experim entation technique was ex tended to 2,4-dihydroxyquinoline (la) with chromanones (7) with vinyl...

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A convenient approach to the synthesis of prenyl-, furo- and pyrano-quinoline alkaloids of the rutaceae

Cited by 29 publications

References 12 publications

6‐Methoxy‐2‐oxo‐1,2‐dihydroquinoline‐3,4‐dicarbonitriles, A Red Compound Class with Solvent and pH Independent Green Fluorescence Maxima

6‐Methoxy‐2‐oxo‐1,2‐dihydroquinoline‐3,4‐dicarbonitriles, A Red Compound Class with Solvent and pH Independent Green Fluorescence Maxima

Quinoline Alkaloids. Synthesis of Khaplofoline, Ribalinine, and Flindersine

A Facile Synthesis of Naphthyl-Quinolyl Ethanes and Chromenyl-Quinolyl Ethanes

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