- 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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- Natural (-)-vasicine as a novel source of optically pure 1-benzylpyrrolidin-3-ol
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A facile and scalable methodology for the preparation of optically active (3S)-1-benzylpyrrolidin-3-ol (3), an important drug precursor, is reported. Starting from the naturally occurring alkaloid (-)-vasicine (1), a major alkaloid of the plant Adhatoda vasica, 3 was obtained in 84% overall yield (Scheme 3). Copyright
- Aga, Mushtaq A.,Kumar, Brijesh,Rouf, Abdul,Shah, Bhahwal A.,Andotra, Samar S.,Taneja, Subhash C.
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p. 969 - 977
(2013/06/27)
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- Oxidative rearrangement of spiro cyclobutane cyclic aminals: Efficient construction of bicyclic amidines
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A new rearrangement reaction of spirocyclic cyclobutane N-halo aminals is described. This process, promoted by treatment of the aminals with N-halosuccinimides (NXS, X = Br or Cl), efficiently produces bicyclic amidines by a pathway involving initial N-ha
- Murai, Kenichi,Komatsu, Hideyuki,Nagao, Ryu,Fujioka, Hiromichi
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p. 772 - 775
(2012/03/26)
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- Reaction of deoxyvasicinone with organolithium compounds
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4-Butyl-4-hydroxydeoxypeganine was prepared by lithiation of deoxyvasicinone. Deoxypeganine and 1,2-dihydrodeoxypeganine were produced by reduction of deoxyvasicinone with lithium aluminum hydride.
- Shakhidoyatov,Ibragimov,Mukhamedov
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experimental part
p. 598 - 599
(2010/12/25)
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- Pyrrolidinohydroquinazolines - A novel class of CCR3 modulators
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A novel class of CCR3 modulators is described. Starting with lead compound 4a (Ki: 110 nM), which turned out to be an antagonist of eotaxin at the CCR3 receptor, further optimization led to compound 8b (Ki: 28 nM), which surprisingly
- Anderskewitz, Ralf,Bauer, Rolf,Bodenbach, Gisela,Gester, Dirk,Gramlich, Bernd,Morschhaeuser, Gerd,Birke, Franz W.
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p. 669 - 673
(2007/10/03)
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- Pyrrolidinohydrochinazolines
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Disclosed are compounds of formula (I): or stereoisomers or pharmaceutically acceptable salts thereof, wherein the groups Ar1, Ar2, A, R1, R2, R3, E1, E2, X and n are as defined
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Page/Page column 10
(2008/06/13)
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- PYRROLIDINOHYDROCHINAZOLINES
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The invention relates to the novel compounds of formula (I) or stereoisomers or pharmaceutically acceptable salts thereof, wherein the groups Ar1, Ar2, A, R1, R2, R3, E1, E2, X a
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- METHODS FOR PRODUCING QUINAZOLINE ALKALOIDS
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The invention relates to a method for producing a compound of formula (I) by reacting a compound of formula (II) with 2-pyrrolidone, whereby a surplus of 2-pyrrolidone, in relation to compound (II), is used. The invention also relates to a method for producing a compound of formula (III), comprising the following steps: (A) production of compound (I); (B) reduction reaction to obtain compound (III) in the form of a salt; (C) release of compound (III) from the salt.
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Page/Page column 12
(2008/06/13)
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- Alkaloids of Nitraria komarovii. Structures of komarin and peganol-N-oxide
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Two alkaloids are isolated from the aerial portions of Nitraria komarovii. Their structures are determined using spectral data and chemical transformations.
- Tulyaganov,Makhmudov
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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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p. 737 - 742
(2007/10/03)
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- Alkaloids of Nitraria komarovii. XVII. Peganine N-oxide, N-allylschoberine, and dehydronitramidine
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Three new alkaloids have been isolated from the epigeal part of Nitraria komarovii - peganine N-oxide, N-allylschoberine, and dehydronitramidine.Their structures have been determined on the basis of chemical transformations and spectral results.
- Tulyaganov, T. S.
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p. 727 - 729
(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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- Synthesis of Vasicine Analogues
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A number of vasicine analogues have been synthesised by the condensation of deoxyvasicine (I) with different aromatic aldehydes and screened for biological activity.
- Gupta, V. N.,Jain, M. P.,Atal, C. K.
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