- OCCURRENCE IN HIGHER PLANTS OF 1-(3-AMINOPROPYL)-PYRROLINIUM AND PYRROLINE: PRODUCTS OF POLYAMINE OXIDATION
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The presence of 1-(3-aminopropyl)pyrrolinium (App) has been established in the leaves of oats, maize, barley and wheat seedlings.In oat leaves, concentrations of 1,3-diaminopropane (Dap), putrescine (Put) and App were greatest in the youngest plants.Changes in Dap and App could not be correlated with changes in polyamine oxidase activity.Concentrations of the amines were smaller in maize than in oats, and smallest in barley and wheat.Pyrroline, an oxidation product of Put in pea seedlings and of spermidine in oat and maize seedlings, has been demonstrated in extracts of these plants, and also in spinach leaves and in radish shoots, following distillation, derivatization with 2-aminobenzaldehyde, oxidation of the adduct and GC-MS.Piperideine was also identified in pea seedlings.Key Word Index- Gramineae; Leguminosae; 1-(3-aminopropyl)-2-pyrrolinium; 1-pyrroline; 1-piperideine; 2-aminobenzaldehyde adduct; 2,3-trimethylene-4-quinazolone; spermine; diaminopropane; amine oxidases.
- Smith, Terence A.,Croker, Stephen J.,Loeffler, R. S. Thomas
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- Peroxide-Mediated Oxidative Radical Cyclization to the Quinazolinone System: Efficient Syntheses of Deoxyvasicinone, Mackinazolinone and (±)-Leucomidine C
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An efficient protocol for obtaining fused quinazolinones through an oxidative free-radical cyclization under metal- and tin-free conditions is described. The oxidative cyclization of various N -3-ω-iodoalkyl derivatives to provide tricyclic systems using dicumyl peroxide as the sole reagent is studied. The method then is employed for the syntheses of 5-, 6-, and 7-membered fused quinazolinone analogues, including the natural products deoxyvasicinone and mackinazolinone. A xanthate-based oxidative radical cascade addition/cyclization process that allows the production of new menthol- and testosterone-quinazolinone conjugates, as well as the first total synthesis of leucomidine C, are also reported.
- García-Ramírez, Jazmín,Miranda, Luis D.
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- Solid-phase synthesis of fused [2,1-b]quinazolinone alkaloids
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Solid-phase synthesis of fused [2,1-b]quinazolinone alkaloids has been developed for the preparation of vasicinone and deoxyvasicinone by two approaches. The derivative of polymer-supported p-nitrophenyl carbonate was attached to anthranilic acid and then coupled with various bromo-lactams. This resin-linked bromo intermediate upon acetylation, hydrolysis and resin cleavage gave the cyclized [2,1-b]quinazolinones (vasicinone). Alternatively, resin-linked azido-benzoic acids were coupled with bromo-substituted lactams followed by cyclization in an aza-Wittig reductive cyclization process giving the bromo-substituted quinazolinone intermediates, with subsequent acetylation, hydrolysis and resin cleavage affording the fused [2,1-b]quinazolinones.
- Kamal, Ahmed,Shankaraiah,Devaiah,Reddy, K. Laxma
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- Novel one-pot total syntheses of deoxyvasicinone, mackinazolinone, isaindigotone, and their derivatives promoted by microwave irradiation
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(Chemical Equation Presented) Total syntheses of deoxyvasicinone (1), mackinazolinone (2), and 8-hydroxydeoxyvasicinone (3) via novel microwave-assisted domino reactions, as well as a novel three-component one-pot total synthesis of isaindigotone (5) promoted by microwave irradiation, are reported. The efficient reaction process enabled us to rapidly access related natural product derivatives and to identify a new class of cytotoxic agents.
- Liu, Ji-Feng,Ye, Ping,Sprague, Kevin,Sargent, Katie,Yohannes, Daniel,Baldino, Carmen M.,Wilson, Christopher J.,Ng, Shi-Chung
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- Acetylcholinesterase inhibition by fused dihydroquinazoline compounds
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A new type of dihydroquinazoline-based inibitor of acetylcholinesterase (AChE) is described. These compounds were designed to interact with the catalytic site of AChE in a manner similar to the known inhibitor tacrine. In a manner analogous to the potency enhancement obtained by addition of chlorine atoms to the tacrine molecule, a 3-chloro derivative of the parent hexahydroazepino[2,1-b]quinazoline structure was found to be about 8 times more potent as an AChE inhibitor than the unsubstituted compound.
- Jaen, Juan C.,Gregor, Vlad E.,Lee, Chet,Davis, Robert,Emmerling, Mark
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- Synthesis of 3,4-dihydroquinazolin-4-one: Selenium-catalyzed reductive N-heterocyclization of N-(2-nitrobenzoyl)amides with carbon monoxide
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A catalytic synthetic method of 3,4-dihydroquinazolin-4-ones has been developed. When N-(2-nitrobenzoyl)amides were treated with carbon monoxide in the presence of a catalytic amount of selenium, reductive N-heterocyclization of N-(2-nitrobenzoyl)amide efficiently proceeded to give the corresponding 3,4-dihydroquinazolin-4-ones in moderate to good yields.
- Nishiyama, Yutaka,Hirose, Masaharu,Kitagaito, Wataru,Sonoda, Noboru
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Read Online
- Deacylation-aided C–H alkylative annulation through C–C cleavage of unstrained ketones
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Arene- and heteroarene-fused rings are pervasive in biologically active molecules. Direct annulation between a C–H bond on the aromatic core and a tethered alkyl moiety provides a straightforward approach to access these scaffolds; however, such a strategy is often hampered by the need of special reactive groups and/or less compatible cyclization conditions. It would be synthetically appealing if a common native functional group can be used as a handle to enable a general C–H annulation with diverse aromatic rings. Here, we show a deacylative annulation strategy for preparing a large variety of aromatic-fused rings from linear simple ketone precursors. The reaction starts with homolytic cleavage of the ketone α C–C bond via a pre-aromatic intermediate, followed by a radical-mediated dehydrogenative cyclization. Using widely available ketones as the robust radical precursors, this deconstructive approach allows streamlined assembly of complex polycyclic structures with broad functional group tolerance. [Figure not available: see fulltext.]
- Dong, Guangbin,Xu, Yan,Zhou, Xukai
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p. 703 - 710
(2021/08/09)
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- The novel acid-base magnetic recyclable catalyst prepared through carbon disulfide trapping process: Applied for green, one-pot, and efficient synthesis of 2,3-dihydroquinazolin-4 (1H) -ones and bis(indolyl)methanes in large-scale
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Herein, a nano acid-base catalyst using magnetic core and carbamodithioic acid functional group have been synthesized and characterized. Its efficiency in the synthesis of dihydroquinazolinones and bis(indolyl)methanes derivatives was investigated. This novel metal-free catalyst exhibited significant catalytic activity in both reactions under green and mild reaction conditions (the yield obtained for the first reaction products: 82–98 % and for the second one: 61–97 %). The catalyst displayed good recyclability with no significant loss of catalytic activity after eight runs (the conversion of the eighth run was found as 83 %, the fresh catalyst conversion was 95 %). The introduced approach is attractive due to its applicability in the large-scale synthesis of important medicinal compounds.
- Mohammadi Metkazini, Fatemeh,Khorsandi, Zahra,Heydari, Akbar
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- Redox Condensations of o-Nitrobenzaldehydes with Amines under Mild Conditions: Total Synthesis of the Vasicinone Family
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A total synthesis of the vasicinone family of natural products from bulk chemicals was developed. Reductive condensation of o-nitrobenzaldehydes with amines utilizing iron pentacarbonyl as a reducing agent followed by subsequent oxidation leads to a great variety of polycyclic nitrogen-containing heterocycles under mild conditions. Enantiomerically pure vasicinone, rutaecarpine, isaindigotone, and luotonin were synthesized from readily available starting materials like hydroxyproline, nitrobenzaldehyde, pyrrolidine, and piperidine in two to four operational steps without chromatography. The antifungal activity of all products was tested.
- Afanasyev, Oleg I.,Podyacheva, Evgeniya,Rudenko, Alexander,Tsygankov, Alexey A.,Makarova, Maria,Chusov, Denis
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p. 9347 - 9360
(2020/08/14)
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- Novel PDE5 inhibitors derived from rutaecarpine for the treatment of Alzheimer's disease
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A series of novel rutaecarpine derivatives were synthesized and subjected to pharmacological evaluation as PDE5 inhibitors. The structure–activity relationships were discussed and their binding conformation and simultaneous interaction mode were further clarified by the molecular docking studies. Among the 25 analogues, compound 8i exhibited most potent PDE5 inhibition with IC50 values about 0.086 μM. Moreover, it also produced good effects against scopolamine-induced cognitive impairment in vivo. These results might bring significant instruction for further development of potential PDE5 inhibitors derived from rutaecarpine as a good candidate drug for the treatment of Alzheimer's disease.
- Dong, Yan-Hua,Huang, Xian-Feng,Ke, Heng-Ming,Song, Guo-Qiang,Wang, Jin-Hui,Xu, De-Feng
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supporting information
(2020/03/23)
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- Stable iridium(iv) complexes supported by tetradentate salen ligands. Synthesis, structures and reactivity
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A series of trans-dichloroiridium(iv)-salen complexes were synthesized and structurally characterized by spectroscopic means and X-ray crystal structures. These Ir(iv) complexes are able to catalyze intramolecular C-H amination of aryl azides. The catalytic amination was drastically accelerated under microwave-assisted conditions, and possibly involves Ir-imido intermediates as supported by high-resolution ESI-MS analysis.
- Lee, Chi Lun,Wu, Liangliang,Huang, Jie-Sheng,Che, Chi-Ming
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supporting information
p. 3606 - 3609
(2019/03/26)
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- One-Pot Synthesis of Quinazolin-4(3H)-ones through Anodic Oxidation and the Related Mechanistic Studies
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A metal-free and oxidant-free method for the one-pot preparation of quinazolin-4(3H)-ones enabled by electrochemical oxidation is described. Together with 2-aminobenzamides, a variety of aldehydes were successfully applied to an acid-catalyzed annulation and direct anodic oxidation cascade, affording structurally diverse quinazoline-4(3H)-ones in good to excellent yields. Additionally, certain alcohols can be directly applied instead of the corresponding aldehydes to achieve the same final products with the assistance of an electrolysis mediator (TEMPO). The reaction mechanism was carefully examined and the results strongly suggest that the direct and indirect oxidation go through different pathways. As an efficient and environmentally friendly access to a broad range of quinazolin-4(3H)-ones, the synthetic utility of this method was demonstrated by gram-scale operation, as well as the preparation of bioactive mackinazolinone and truncated erlotinib. (Figure presented.).
- Cao, Liu,Huo, Hengrui,Zeng, Haipeng,Yu, Yu,Lu, Dengfu,Gong, Yuefa
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p. 4764 - 4773
(2018/11/10)
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- On the Synthesis and Reactivity of 2,3-Dihydropyrrolo[1,2- a ]quinazolin-5(1 H)-ones
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An improved, scalable synthetic route to the quinazolinone natural product 2,3-dihydropyrrolo[1,2-a]quinazolin-5(1H)-one is reported. The applicability of this method to analogue synthesis and the synthesis of related natural products is explored. Finally, reactivity of the scaffold to a variety of electrophilic reagents, generating products stereoselectively, is reported.
- Sutherell, Charlotte L.,Ley, Steven V.
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p. 135 - 144
(2016/12/24)
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- [Fe(F20TPP)Cl]-catalyzed amination with arylamines and {[Fe(F20TPP)(NAr)](PhI=NAr)}+. Intermediate assessed by high-resolution ESI-MS and DFT calculations
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Amination of C-H bonds catalyzed by transition metal complexes via nitrene/imide insertion is an appealing strategy for C-N bond formation, and the use of iminoiodinanes, or their in situ generated forms from 'PhI-(OAc)2 + primary amides (such as sulfonamides, sulfamates, and carbamates)', as nitrogen sources for the amination reaction has been well documented. In this work, a 'metal catalyst + PhI(OAc)2 + primary arylamines' amination protocol has been developed using [Fe(F20TPP)Cl] (H2F20TPP = meso-tetrakis(pentafluorophenyl)porphyrin) as a catalyst. This catalytic method is applicable for both intra- and intermolecular amination of sp2 and sp3 C-H bonds (> 27 examples), affording the amination products, including natural products such as rutaecarpine, in moderate-to-good yields. ESI-MS analysis and DFT calculations lend support for the involvement of {[Fe(F20TPP)(NC6H4-p-NO2)](PhI=NC6H4-p-NO2)}+. intermediate in the catalysis.
- Liu, Yungen,Chen, Guo-Qiang,Tse, Chun-Wai,Guan, Xianguo,Xu, Zheng-Jiang,Huang, Jie-Sheng,Che, Chi-Ming
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supporting information
p. 100 - 105
(2015/02/19)
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- Development of a New Synthetic Method for Quinazolinones via Aerobic Oxidation in dimethylsulfoxide
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The present invention relates to a method for preparing quinazoline derivatives by aerobic oxidation using oxygen as an oxidizing agent in dimethylsulfoxide (DMSO) solvent wherein metal and base are excluded. The method for preparing quinazoline derivatives according to the present invention does not require any metal catalyst such as palladium or iridium, and thus does not cause toxicity problem of residual metal; and does not require demanding processes such as strong acid, or base conditions, low temperature reactions, or reactions of anhydrous conditions and thus, it is possible to simply and economically prepare quinazoline derivatives by reacting anthranilamide derivatives and an aldehyde source.
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Paragraph 0235-0238
(2021/03/30)
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- Synthesis of quinazolinones from anthranilamides and aldehydes via metal-free aerobic oxidation in DMSO
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A highly environmentally benign protocol for the synthesis of quinazolinones from anthranilamides and aldehydes via aerobic oxidation was developed in wet DMSO. This protocol is operationally simple, exhibits broad substrate scope, and does not need toxic metal catalysts and bases. In addition, the utility of this transformation was further demonstrated by converting the resulting quinazolinones into other useful products in the same-pot without their isolation.
- Kim, Na Yeun,Cheon, Cheol-Hong
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supporting information
p. 2340 - 2344
(2014/05/06)
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- Design, synthesis and evaluation of arylidene pyrrolo and pyrido fused quinazolones as antimicrobial agents
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Keeping in view the potential of heterocyclic fused quinazolones and arylidene linked heterocycles , hybrid molecules of these functionalities were designed and synthesised. All the synthesised molecules were characterized by spectroscopic techniques and evaluated for antimicrobial activity against 2 Gram positive bacterial strains; Staphylococcus aureus (MTCC 96) and Bacillus subtilis (MTCC 2451), 3 Gram negative bacterial strains; Escherichia coli (MTCC 82), Pseudomonas aeruginosa (MTCC 2642) and Salmonella typhimurium (MTCC 1251) and 2 fungal strains; Saccharomyces cerevisiae (MTCC 2799) and Candida albicans (MTCC 3018). Among the synthesised molecules, arylidene pyrrolo fused quinazolones displayed significant antimicrobial activity in comparison to arylidene pyrido fused quinazolones. The influence of the electronic factors linked with the arylidene ring was also observed on the antimicrobial potential. Thus the present study highlights the potential of such hybrid molecules as a new class of antimicrobials.
- Nepali, Kunal,Ojha, Ritu,Singh, Aninder,Budhiraja, Abhishek,Bedi, Preet Mohinder Singh,Dhar, Kanaya Lal
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p. 522 - 528
(2013/07/26)
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- Structure activity relationship of arylidene pyrrolo and pyrido [2,1-b] quinazolones as cytotoxic agents: Synthesis, SAR studies, biological evaluation and docking studies
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Tubulin is the one of the most useful and strategic molecular targets for anticancer drugs. Agents that bind in Colchicine-binding site of tubulin include Phenstatin, Combretastatin A-4, Colchicine, Steganacin, Podophyllotoxin and certain other synthetic analogues of these compounds. Arylidene pyrollo and pyrido [2,1-b] quinazolones (isoindigatone and its synthetic analogues) have been earlier reported to be tubulin inhibitors evidenced by tubulin polymerization assay. The present study is an extension of the library of the isoindigatone and its synthetic analogues to generate the structure activity relationship. The study explores the role of the arylidene ring and also provides some intresting observations such as the placement of bicyclic ring such as naphylidene for potential activity. Some of the important interactions of KNH-3 and KNH-11 with the amino acid residues of active site of Tubulin have also been observed by molecular modeling.
- Mangla, Veenu,Nepali, Kunal,Singh, Gagandip,Singh, Jagjeet,Guru, Santosh,Gupta, Manish Kumar,Mahajan, Priya,Saxena, Ajit Kumar,Dhar, Kanaya Lal
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p. 642 - 650
(2013/09/23)
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- Facile access to ring-fused aminals via direct α-amination of secondary amines with o-aminobenzaldehydes: Synthesis of vasicine, deoxyvasicine, deoxyvasicinone, mackinazolinone, and ruteacarpine
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Secondary amines undergo redox-neutral reactions with aminobenzaldehydes under conventional and microwave heating to furnish polycyclic aminals via amine α-amination/N-alkylation. This unique α-functionalization reaction proceeds without the involvement of transition metals or other additives. The resulting aminal products are precursors for various quinazolinone alkaloids and their analogues. Georg Thieme Verlag Stuttgart. New York.
- Richers, Matthew T.,Deb, Indubhusan,Platonova, Alena Yu.,Zhang, Chen,Seidel, Daniel
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p. 1730 - 1748
(2013/07/26)
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- Selective copper(II) acetate and potassium iodide catalyzed oxidation of aminals to dihydroquinazoline and quinazolinone alkaloids
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Copper(II) acetate/acetic acid/O2 and potassium iodide/tert-butylhydroperoxide systems are shown to affect the selective oxidation of ring-fused aminals to dihydroquinazolines and quinazolinones, respectively. These methods enable the facile preparation of a number of quinazoline alkaloid natural products and their analogues.
- Richers, Matthew T.,Zhao, Chenfei,Seidel, Daniel
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supporting information
p. 1194 - 1201
(2013/07/26)
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- New topoisomerases inhibitors: Synthesis of rutaecarpine derivatives and their inhibitory activity against topoisomerases
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A series of rutaecarpine derivatives were prepared by employing previously reported methods and their inhibitory activities against topoisomerase I and II were evaluated. Among them, strongly cytotoxic 10-bromorutaecarpine and 3-chlororutaecarpine showed strong inhibitory activities against topo I and II.
- Kim, Seung Ill,Lee, Seung Ho,Lee, Eung-Seok,Lee, Chong-Soon,Jahng, Yurngdong
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experimental part
p. 785 - 789
(2012/08/29)
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- Efficient syntheses of 2,3-disubstituted natural quinazolinones via iridium catalysis
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Natural products sclerotigenin, pegamine, deoxyvasicinone, mackinazolinone, and rutaecarpine were synthesized. Core quinazolinone structures were constructed via Ir catalysis. The Royal Society of Chemistry 2012.
- Fang, Jie,Zhou, Jianguang
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p. 2389 - 2391
(2012/04/11)
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- [Fe(F20TPP)Cl] catalyzed intramolecular C-N bond formation for alkaloid synthesis using aryl azides as nitrogen source
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The syntheses of alkaloids including indoles, indolines, tetrahydroquinolines, dihydroquinazolinones and quinazolinones have been accomplished in moderate to excellent yields via [Fe(F20TPP)Cl] catalyzed intramolecular C-N bond formation using aryl azides as nitrogen source.
- Liu, Yungen,Wei, Jinhu,Che, Chi-Ming
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supporting information; experimental part
p. 6926 - 6928
(2010/11/16)
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- Synthesis and vasodilator effects of rutaecarpine analogues which might be involved transient receptor potential vanilloid subfamily, member 1 (TRPV1)
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Rutaecarpine is the major alkaloid component of Wu-Chu-Yu, a well known Chinese herbal drug. It has been reported that rutaecarpine causes the vasodilator, hypotensive effects by stimulation of CGRP synthesis and release via activation of TRPV1. In present study, 23 rutaecarpine analogues were designed and synthesized. Then, the vasodilator effects of theses compounds were screened by rat aortic ring experiment. The result showed that the 14-N atom of rutaecarpine might be the key site for the activity. The 5-carbonyl might make lower contribution to the effect. And simple substitute in indole-ring or quinazoline-ring would not enhance the vasodilator effect unless in proper position with proper group. One of these compounds, 10-methylrutaecarpine, exhibited similar effect with rutaecarpine. Further functional experiments showed its vasodilator and hypotensive effect were related to the stimulation of CGRP release via activation of TRPV1. The vasodilator effects of these compounds were evaluated and the structure-activity relationship was elucidated for the first time. The results suggested a new direction of valuable TRPV1 agonist as anti-hypertensive drugs.
- Chen, Zhuo,Hu, Gaoyun,Li, Dai,Chen, Jun,Li, Yuanjian,Zhou, Huayong,Xie, Ye
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experimental part
p. 2351 - 2359
(2009/09/08)
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- Chemoselective aromatic azido reduction with concomitant aliphatic azide employing Al/Gd Triflates/Nal and ESI-MS mechanistic studies
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Aluminium and gadolinium inflates catalyze the chemoselective reduction of aromatic azides to the corresponding amines in combination with sodium iodide. This mild chemoselective method has been applied to the synthesis of various aryl amines, C2azido-substituted pyrrolo[2,1-c]-[1,4]benzodiazepines, and fused[2,1b]quinazolinones by an intramolecular azido reduction tandem cyclization reaction. Interestingly, this methodology selectively reduces aryl azides with enhanced yields and proceeds in shorter reaction times than previous strategies. The mechanistic aspects have been investigated and the intermediates associated with this selective transformation have been intercepted and characterized by online monitoring of the reaction by ESI-MS.
- Kamal, Ahmed,Markandeya, Nagula,Shankaraiah, Nagula,Ratna Reddy,Prabhakar,Sanjeeva Reddy,Eberlin, Marcos N.,Santos, Leonardo Silva
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experimental part
p. 7215 - 7224
(2010/03/05)
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- One-pot synthesis of simple alkaloids: 2,3-Polymethylene-4(3H)- quinazolinones, luotonin A, tryptanthrin, and rutaecarpine
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One-pot synthesis of various 2,3-polymethylene-4(3H)-quinazolinones from anthranilic acid, corresponding lactam and SOCl2 is described, which can be applicable to the synthesis of simple 4(3H)-quinazolinone-derived alkaloids, such as luotonin A, tryptanthrin, and rutaecarpine.
- Jahng, Katherine Chae,Kim, Seung Ill,Kim, Dong Hyeon,Seo, Chang Seob,Son, Jong-Keun,Lee, Seung Ho,Lee, Eung Seok,Jahng, Yurngdong
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experimental part
p. 607 - 609
(2009/04/06)
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- Radical reactions with 3H-quinazolin-4-ones: Synthesis of deoxyvasicinone, mackinazolinone, luotonin A, rutaecarpine and tryptanthrin
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Alkyl, aryl, heteroaryl and acyl radicals have been cyclised onto the 2-position of 3H-quinazolin-4-one. The side chains containing the radical precursors were attached to the nitrogen atom in the 3-position. The cyclisations take place by aromatic homolytic substitution hence retain the aromaticity of the 3H-quinazolin-4-one ring. The highest yields were obtained using hexamethylditin to facilitate cyclisation rather than reduction without cyclisation. The alkaloids deoxyvasicinone 2, mackinazolinone 3, tryptanthrin 4, luotonin A 5 and rutaecarpine 8 were synthesised by radical cyclisation onto 3H-quinazolin-4-one. This journal is The Royal Society of Chemistry.
- Bowman, W. Russell,Elsegood, Mark R. J.,Stein, Tobias,Weaver, George W.
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p. 103 - 113
(2008/03/14)
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- Privileged structure-based quinazolinone natural product-templated libraries: Identification of novel tubulin polymerization inhibitors
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A focused quinazolinone natural product-templated library was designed and synthesized. Compounds from this privileged structure-based library were identified as antimitotic agents acting through destabilization of tubulin polymerization. The results suggested that 2 could be a privileged substructure.
- Liu, Ji-Feng,Wilson, Christopher J.,Ye, Ping,Sprague, Kevin,Sargent, Katie,Si, Ying,Beletsky, Galina,Yohannes, Daniel,Ng, Shi-Chung
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p. 686 - 690
(2007/10/03)
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- A polymer-assisted solution-phase strategy for the synthesis of fused [2,1-b]quinazolinones and the preparation of optically active vasicinone
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An efficient preparation of fused [2,1-b]quinazolinones has been developed utilizing polymer-supported reagents. (±)- Vasicinone was converted into its dione by oxidation with poly (4-vinylpyridiniumdichromate). An efficient method has been developed for the synthesis of (d)- and (l)-vasicinone via asymmetric reduction of pyrrolo[2,1-b]quinazoline-3,9-dione by employing NaBH4/Me3SiCl as the reducing agent and polymer-supported chiral sulfonamide as catalyst. Georg Thieme Verlag Stuttgart.
- Kamal, Ahmed,Devaiah,Shankaraiah,Laxma Reddy
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p. 2609 - 2612
(2008/09/16)
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- Synthesis and structure-activity relationships of vasicine analogues as bronchodilatory agents
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The series of vasicine (1) analogues, an alkaloid from Adhatoda vasica Nees., were synthesized with changes in A, B or C rings. Compounds 3-19 were evaluated for in vitro bronchodilatory activity using isolated guinea pig tracheal chain. Compounds 3-8 were also synthesized in good yields using microwave-mediated synthesis under solvent free conditions. Compounds 5 and 8 with seven-member C ring were more active than etofylline and caused 100% relaxation of both the histamine and acetylcholine pre-contracted guinea pig tracheal chain. The structure-activity relationship studies showed that the quinazoline and oxo functionalities were essential for activity. The compounds without C ring and instead having aliphatic and phenyl substitutions in B ring showed relaxation against histamine pre-contracted tracheal chain only, 2-methyl substituted analogues, 12 and 13, being most active with 100% relaxation effect. Birkhaeuser Boston 2006.
- Mahindroo, Neeraj,Ahmed, Zabeer,Bhagat, Asha,Bedi, Kasturi Lal,Khajuria, Ravi Kant,Kapoor, Vijay Kumar,Dhar, Kanaya Lal
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p. 347 - 368
(2007/10/03)
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- Efficient solid-phase synthesis of highly functionalized 1,4-benzodiazepin-5-one derivatives and related compounds by intramolecular aza-wittig reactions
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Due to their widespread biological activities and favorable pharmacokinetic properties, benzodiazepines were among the first classes of small molecules to be synthesized on solid supports. Since then, there have been numerous reports on the synthesis of similar skeletons. We have employed the T1 triazene linker to yield 1,4-benzodiazepin-5-one. Starting from various substituted triazene resins, cleavage in the presence of an azide donor, such as trimethylsilylazide, gave rise to aryl azides. Intramolecular aza-Wittig reactions produced the appropriately functionalized N-heterocycles. By using this route, the natural product deoxyvasicinone and related compounds were prepared.
- Gil, Carmen,Braese, Stefan
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p. 2680 - 2688
(2007/10/03)
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- 7,8,9,10-TETRAHYDRO-6H-AZEPINO, 6,7,8,9-TETRAHYDRO-PYRIDO AND 2,3-DIHYDRO-2H-PYRROLO[2,1-B]-QUINAZOLINONE DERIVATIVES
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The invention relates to novel 7,8,9,10-tetrahydro-6H-azepino, 6,7,8,9-tetrahydro-pyrido and 2,3-dihydro-2H-pyrrolo[2,1-b]-quinazolinone derivatives of formula (I) and their use as active ingredients in the preparation of pharmaceutical compositions. The invention also concerns related aspects including processes for the preparation of the compounds, pharmaceutical compositions containing one or more of those compounds and especially their use as orexin receptor antagonists.
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Page/Page column 26
(2010/11/30)
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- Facile zeolite induced Fischer-indole synthesis: A new approach to bioactive natural product rutaecarpine
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Starting from glutaric anhydride (5) we have demonstrated an elegant six-step practical synthesis of bioactive natural product rutaecarpine (1a) via o-amidoglutaranilic acid formation, esterification, chemoselective ester reduction, intramolecular dehydrative cyclizations, hydrazone formation and zeolite induced Fischer-indole synthesis with 53% overall yield. The conditions employed in the present synthesis are mild, efficient and general.
- Mhaske, Santosh B.,Argade, Narshinha P.
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p. 3417 - 3420
(2007/10/03)
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- One pot conversion of azido arenes to N-arylacetamides and N-arylformamides: Synthesis of 1,4-benzodiazepine-2,5-diones and fused [2,1-b]quinazolinones
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Sodium iodide in acidic media has been employed for the synthesis of N-arylformamides and N-arylacetamides. The NaI/acetic acid reagent system has also been extended for the synthesis of 1,4-benzodiazepine-2,5-diones, pyrrolo[2,1-c][1,4]benzodiazepine-5,11-diones, and fused [2,1-b]quinazolinones.
- Kamal, Ahmed,Ramana, A. Venkata,Reddy, K. Srinivasa,Ramana, K. Venkata,Hari Babu,Prasad, B. Rajendra
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p. 8187 - 8190
(2007/10/03)
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- A facile synthesis of simple alkaloids - Synthesis of 2,3-polymethylene-4(3H)-quinazolinones and related alkaloids
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An efficient procedure for preparation of the simple alkaloids, 2,3-polymethylene-4(3H)-quinazolinones, luotonin A, tryptanthrin, and rutaecarpine has been established by the reaction of lactam-HCl salts with POCl3 followed by cyclization with methyl anthranilate.
- Lee, Eung Seok,Park, Jae-Gyu,Jahng, Yurngdong
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p. 1883 - 1886
(2007/10/03)
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- Microwave-assisted rapid synthesis of the cytotoxic alkaloid luotonin A
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The total synthesis of the cytotoxic alkaloid luotonin A has been achieved for the first time in high yields by the cyclocondensation of 3-oxo-1H-pyrrolo[3,4-b]quinoline with isatoic anhydride in solvent-free conditions under microwave irradiation.
- Yadav,Reddy
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p. 1905 - 1907
(2007/10/03)
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- Mild and efficient reduction of azides to amines: Synthesis of fused [2,1-b]quinazolinones
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FeCl3/NaI has been employed for an efficient reduction of a variety of azides. This method is selective in the presence of a nitro functionality and has been extended for the synthesis of fused [2,1-b]quinazolinone ring systems such as deoxyvasicinone.
- Kamal, Ahmed,Ramana, K.Venkata,Ankati, Hari Babu,Ramana, A.Venkata
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p. 6861 - 6863
(2007/10/03)
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- Chemoenzymatic synthesis of pyrrolo[2,1-b]quinazolinones: Lipase-catalyzed resolution of vasicinone
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A facile synthesis of bronchodilatory pyrrolo[2,1-b]quinazoline alkaloids by azidoreductive cyclization strategy employing TMSCl-NaI and bakers' yeast is described. Both the chemical and enzymatic methods are mild and take place at room temperature in good yields. Further, synthesis and resolution of vasicinone has been carried out by employing different lipases. It has been observed that lipase PS provides acetate of (S)-vasicinone in 98% ee.
- Kamal,Ramana,Rao
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p. 997 - 1001
(2007/10/03)
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- Studies on Some Biologically Active Azepinoquinazolines: Part I - An Approach to Potent Bronchodilatory Compounds
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Twenty six azepinoquinazolines have been prepared and screened for their bronchodilatory activity.Out of these compounds, 7,8,9,10-tetrahydroazepinoquinazolin-12(6H)-one (III) has been found as an excellent bronchodilatory compound. 2,4,6-Tribromo-7,8,9,10-tetrahydroazepinoquinazolin-12(6H)-one (XXIV) shows marked antitussive and mucolytic activities parallel to those of bromhexine.
- Malhotra, S.,Koul, S. K.,Sharma, R. L.,Anand, K. K.,Gupta, O. P.,Dhar, K. L.
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p. 937 - 940
(2007/10/02)
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- New Reactions of Deoxyvasicinone. Part 4.
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Analogues of deoxyvasicinone (1) in which the pyrrolo ring is substituted, enlarged, or attached to the a face of the quinazolone system were prepared and several reactions of these analogues with electrophilic reagents have been investigated.
- Dunn, A. D.,Kinnear, K. I.
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- 3,4,5,6,7,8-Hexahydro-1,7-benzodiazecin-2(1H)-one from Extracts of Mackinlaya Species
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A minor base from Mackinlaya macrosciadia (F.Muell) F.Muell has been shown to be 3,4,5,6,7,8-hexahydro-1,7-benzodiazecin-2(1H)-one.This compound is formed in low yield from decomposition of 6,7,8,9-tetrahydro-11H-pyridoquinazoline, the major base, on storage, and it is conveniently prepared by hydrolysis of the major base in water.
- Johns, Stanley R.,Lamberton, John A.,Suares, Hector
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p. 1007 - 1008
(2007/10/02)
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- Synthesis of Tetrahydropyridoquinazolin-10(H)-one Analogues
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Tetrahydropyridoquinazolin-10(H)-one analogues (III) have been synthesised by the condensation of 1,2,3,4-tetrahydropyridoquinazolin-10(H)-one (I) with different aromatic as well as aliphatic aldehydes (II) and screened for their bronchodilatory and uterotonic activities.Their structures have been established by elemental analyses and spectral data.
- Jain, M. P.,Gupta, V. N.,Atal, C. K.,Nath, L. G. D.
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p. 983 - 984
(2007/10/02)
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- ONE POT SYNTHESIS OF QUINAZOLINE DERIVATIVES BY USE OF PALLADIUM CATALYZED CARBONYLATION
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One pot synthesis of quinazoline derivatives from a mixture of o-iodoaniline 1a and five membered lactams or N-acyl-o-iodoaniline derivatives, 1b and 1c, and primary amines was effected through the palladium-catalyzed insertion of carbon monoxide.
- Mori, Miwako,Kobayashi, Hiromi,Kimura, Masaya,Ban, Yoshio
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p. 2803 - 2806
(2007/10/02)
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- NITROGEN BRIDGEHEAD COMPOUNDS PART 16. FACILE TOTAL SYNTHESIS OF 7,8-DIHYDRO-13H-INDOLOPYRIDO-QUINAZOLIN-5-ONE (RUTECARPINE).
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Rutecarpine 1 has been synthetised from hydrazone 2 in high yield by Fischer indole synthesis.Hydrazone 2 has been prepared from 3 with benzenediazonium chloride or 5 with phenylhydrazine. 2 Shows a solvent dependent E-Z isomerism.
- Koekoesi, Jozsef,Hermecz, Istvan,Szasz, Gyoergy,Meszaros, Zoltan
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p. 4861 - 4862
(2007/10/02)
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- Some reactions of α-hydroxymethylene- and α-dimethylaminomethylene-2,3-polymethylene-3,4-dihydroquinazolin-4-ones
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By the reaction of α-hydroxymethylene- and α-dimethylaminomethylene-2,3-polymethylene-3,4-dihydroquinazolin-4-ones with acid anhydrides and primary and secondary amines, the corresponding α-acyloxymethylene- and α-mono(di)-substituted aminomethylene-2,3-polymethylene-3,4-dihydroquinazolin-4-ones have been synthesized. The addition of hydrocyanic acid (from acetone cyanohydrin) to the double bond of the methylene group of the α-hydroxymethylene- and α-dimethylaminomethylene-2,3-trimethylene-3,4-dihydroquinazolin-4-ones has led to α-[cyano-(hydroxy)methyl1]- and α-[cyano(dimethylamino)methyl]-2,3-trimethylene-3,4-dihydroquinazolin-4-ones.
- Oripov,Yun,Shakhidoyatov,Kadyrov
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p. 518 - 523
(2007/10/04)
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