- An efficient synthesis of 6-(4-chlorophenyl)-2,2-dimethyl-7-phenyl-2,3- dihydro-lh-pyrrolizine, a key intermediate in the licofelone synthesis
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An efficient synthesis of 6-(4-chlorophenyl)-2,2-dimethyl-7-phenyl-2,3- dihydro-1H-pyrrolizine, a key intermediate for the synthesis of licofelone, an anti-inflammatory drug currently undergoing evaluation of the phase-III clinical studies, is described. The method is based on a novel synthesis of unstable 5-benzyl-3,3-dimethyl-3,4-dihydro-2H-pyrrole, which is then treated with 2-bromo-1-(4-chlorophenyl)ethan-1-one. 2,2-Dimethyl-5-phenylpent-4-ynal with benzylamines provides the corresponding Schiff bases. Migration of the C=N double bond in these N-(2,2-dimethyl-5-phenylpent-4-yn-1-ylidene)benzylamines into conjugation with the aromatic ring using various base/solvent systems was studied. Acid hydrolysis of the formed Schiff bases then provided 2,2-dimethyl-5-phenylpent-4-yn-1-amine and 2,2-dimethyl-5-phenylpenta-3,4-dien- 1-amine; their ratio was influenced mainly by the reaction conditions. Cyclization of these amines using Ag or Au catalysts then led to 5-benzyl-3,3-dimethyl-3,4-dihydro-2H-pyrrole.
- Radl, Stanislav,Stach, Jan,Cerny, Josef,Klecan, Ondrej
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- Ruthenium-catalyzed intramolecular oxidative amination of aminoalkenes enables rapid synthesis of cyclic imines
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[RuCl2(CO)3]2/dppp is shown to be a highly effective catalyst system for the first intramolecular oxidative amination of a variety of aminoalkenes when it is used concomitantly with K2CO3 and allyl acetate in N-methylpiperidine, to give the corresponding cyclic imines and indoles in excellent yields. For example, the reaction of 2,2-diphenyl-4-pentenyl-1-amine performed in the presence of 2 mol % of [RuCl2(CO)3]2, 4 mol % of dppp, K2CO3, and allyl acetate in N-methylpiperidine at 140 °C for 8 h gives 4,4-diphenyl-2-methyl-1-pyrroline in quantitative (>99%) yield. Copyright
- Kondo, Teruyuki,Okada, Takumi,Mitsudo, Take-Aki
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- Selective Incorporation of Primary Amines into a Trizirconium Imido System and Catalyic Cyclization of Aminoalkynes
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The trinuclear zirconium imido complex [{LZr(NMe2)}3] (2, L = C5Me4CH2CH2N) was synthesized by amine elimination between Zr(NMe2)4 and endo-olefinic isomers of (tetramethylcyclopentadienyl)ethanamine (LH3) (1). To study the fundamental reactivity of the trizirconium system, reactions of 2 with primary amines were examined. Selective incorporations of the primary amines were observed, depending on steric and electronic natures of the amine substrates. The amine-incorporated complexes [(LZrNHR)(LHZrNHR)(LHZr)(μ-NHR)(μ3-NR)] (3, R = Pr, Et), [(LZrNHR)2(LHZr)(μ-NR)] (4, R = Pr, i-Bu), [(LZr)2(LZrNMe2)(μ-NR)] (5, R = neo-Pen), and [(LZr)(LZrNHAr)(LH2Zr)(μ-NAr)2] (6, Ar = Ph, C6H4-4-Br, C6H4-4-OMe) were structurally characterized by NMR and XRD analysis and showed several coordination modes of the substrate nitrogen ligands: i.e., terminal amides, bridging amides, and bridging imides but not terminal imides. Thermolysis of a mixture of 3 and 4 led to C-H bond activation, giving rise to the zirconaaziridines [{LZr(η2-NCHR)}(LZr)(LHZr)(μ-NHCH2R)] (12, R = Et, Me). Complex 2 proved to be a competent precatalyst in the hydroamination of the aminoalkynes (H2NCH2CR12CH2C=CR2) (13, R1 = H, R2 = Bu, Ph, t-Bu; 14, R1 = Me, R2 = Et, Ph). Stoichiometric or semicatalytic reactions of 2 and the aminoalkynes were studied to explore the reactivity of in situ formed Zr3 species.
- Oishi, Masataka,Nakanishi, Yusuke,Suzuki, Hiroharu
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supporting information
p. 9802 - 9813
(2017/08/26)
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- Investigations on cytotoxicity and anti-inflammatory potency of licofelone derivatives
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A series of C5-substituted licofelone ([2,2-dimethyl-6-(4-chlorophenyl)-7- phenyl-2,3-dihydro-1H-pyrrolizin-5-yl]acetic acid) derivatives were developed by a parallel synthesis approach and investigated for cytotoxicity against MCF-7 and MDA-MB-231 cells as well as for anti-inflammatory potency in vitro and in vivo. Dependent on the C5-substituent, the compounds showed high selectivity for MCF-7 cells. Especially 2-oxoethyl benzoate derivatives were inactive at the MDA-MB-231 cell line and as active as 5-FU at MCF-7 cells. C5-acetyl (8a), -2-oxoethyl formiate (8e), -2-oxoethyl acetate (8f) and -2-oxoethyl propionate (8g) derivatives showed growth inhibition at both cell lines, comparable with cisplatin. Modifications significantly reduced the inhibitory potency at COX-1 and COX-2 in vitro and in the xylene-induced ear swelling assay in mice. Only compound 8a was equipotent to licofelone, ibuprofen and celecoxibe in vivo.
- Liu, Wukun,Zhou, Jinpei,Bensdorf, Kerstin,Zhang, Huibin,Liu, Haoran,Wang, Yubin,Qian, Hai,Zhang, Yanchun,Wellner, Anja,Rubner, Gerhard,Huang, Wenlong,Guo, Cancheng,Gust, Ronald
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scheme or table
p. 907 - 913
(2011/04/19)
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- Licofelone-nitric oxide donors as anticancer agents
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Five licofelone ([2,2-dimethyl-6-(4-chlorophenyl)-7-phenyl-2,3-dihydro-1H- pyrrolizin-5-yl]acetic acid) nitric oxide donor conjugates were developed by a parallel synthesis approach. The biological screening revealed that compounds with a propyl (6b), butyl (6c), or octyl (6d) chain between licofelone and the nitric oxide donor exhibited high antiproliferative potency at MCF-7 and MDA-MB-231 breast cancer as well as at HT-29 colon cancer cells. Moreover, 6b-d possessed at least 2-fold higher cytotoxicity at MDA-MB-231 cells than the parent compound licofelone although they showed less inhibitory activity at COX-1 and COX-2. A correlation between COX inhibition and growth inhibitory properties is not visible. However, the high levels of nitric oxide production of the compounds may result in their high cytotoxic activity. Non-steroidal anti-inflammatory drugs possessing nitric oxide donors are promising anti-inflammatory and anticancer drugs. Herein, a series of licofelone-nitric oxide donors was synthesized and evaluated for their primary biological activities.
- Liu, Wukun,Zhou, Jinpei,Liu, Yinglin,Liu, Haoran,Bensdorf, Kerstin,Guo, Cancheng,Gust, Ronald
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scheme or table
p. 487 - 493
(2011/10/18)
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- Arylpyrrolizines as inhibitors of microsomal prostaglandin E2 synthase-1 (mPGES-1) or as dual inhibitors of mPGES-1 and 5-lipoxygenase (5-LOX)
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We synthesized and evaluated inhibitors for the microsomal prostaglandin E2 synthase-1 (mPGES-1), based on the arylpyrrolizine scaffold. In a cell free mPGES-1 assay several "sulfonimides" exceeded our leadML3000 (3) in potency. The most promising compound, the tolylsulfonimide 11f, revealed an IC50 of 2.1 μM and is equipotent to the literature reference molecule MK886 (1). Selected compounds also potently reduced 5-LOX product formation in intact cells. Inhibition of isolated COX was occasionally remarkably cut down.
- Liedtke, Andy J.,Keck, Peter R. W. E. F.,Lehmann, Frank,Koeberle, Andreas,Werz, Oliver,Laufer, Stefan A.
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scheme or table
p. 4968 - 4972
(2010/03/03)
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- PROCESS FOR THE PREPARATION OF 6-(4-CHLOROPHENYL)-2,2-DIMETHYL-7-PHENYL-2, 3-DIHYDRO-1H-PYRROLIZIN-5-YL ACETIC ACID AND ITS INTERMEDIATES
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The present invention relates to a process for the preparation of 6-(4-chlorophenyl)-2,2-dimethyl-7-phenyl-2, 3-dihydro-1H-pyrrolizin-5-yl acetic acid, in which the key intermediate, 5-Benzyl-3,3-dimethyl-3,4-dihydro-2H-pyrrole is obtained by the hydrogenation of 2,2-dimethyl-4-oxo-5-phenyl-nitropentane. The invention also relates to the preparation of the intermediates occurring in the above process.
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Page/Page column 9-10
(2010/11/28)
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- POLYMORPHIC FORM OF 6- (4-CHLOROPHENYL) -2, 2-DIMETHYL-7-PHENYL-2, 3-DIHYDRO-LH-PYRROLIZIN-5-YLACETIC ACID
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The present invention relates to a new crystalline modification of 6- ( 4-chlorophenyl) -2, 2-dimethyl-7- phenyl-2, S-dihydro-lH-pyrrolizin-S-ylacetic acid which is referred to as polymorph B. It has a peak in the solid state 13C-NMR spectrum (with adamantane as external reference standard; CH group d = 29.45 ppm) in the range from 179.8 to 180.2 ppm and can be processed directly to a pharmaceutical formulation.
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Page/Page column 11-14
(2008/06/13)
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