- Synthesis of 2-Phosphaindolizine and [1,3]Azaphospholo[1,5-a]quinoline
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The reaction of (chloromethyl)dichlorophosphine (1) with 2-[(trimethylsilyl)methyl]pyridine (6) and 2-[(trimethylsilyl)methyl]quinoline (12) in THF affords unsubstituted parent 2-phosphaindolizine (5) and [1,3]azaphospholo[1,5-a]quinoline (7). Multinuclear low-temperature NMR spectroscopy was used to investigate the reaction mechanism; a cascade of substitution and cyclization steps involving transient picolylphosphines and phosphorus heterocycles was identified. The molecular and crystal structures of two heterocyclic intermediates and of 7 were determined by single-crystal X-ray diffraction. Moreover, all intermediates and products were characterized by multinuclear 1H, 13C and 31P NMR spectroscopy.
- Hettstedt, Christina,Mayer, Robert J.,Martens, J?rn F.,Linert, Sarah,Karaghiosoff, Konstantin
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p. 726 - 735
(2016/03/01)
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- Synthesis and SAR of a novel, potent and structurally simple LTD4 antagonist of the quinoline class
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The two geminal ethyl groups in the succinic acid moiety of CGP57698 (4- [3-(7-fluoro-2-quinolinylmethoxy)phenyl-amino]-2,2-diethyl-4-oxo-butanoic acid) are responsible for the high in vitro and in vivo potency of this peptidoleukotriene antagonist of the quinoline type. The synthesis and structure activity relationships of CGP57698 and its analogs are described.
- Von Sprecher, Andreas,Gerspacher, Marc,Beck, Andreas,Kimmel, Sabine,Wiestner, Hansruedi,Anderson, Gary P.,Niederhauser, Ulrich,Subramanian, Natarajan,Bray, Michael A.
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p. 965 - 970
(2007/10/03)
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- Studies on Tertiary Amine Oxides. LXXV. Reactions of Aromatic N-oxides with Meldrum's Acid in the Presence of Acetic Anhydride
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Reactions of quinoline, lepidine, 4-chloro-, 4-methoxy- and 4-morpholino-quinoline 1-oxides (1a-e) with Meldrum's acid (2) in acetic anhydride smoothly occurred at room temperature to afford the corresponding 5-(2-quinolyl)-Meldrum's acids (3a-e) in good yields.On the other hand, when the reactions were carried out in dimethylformamide containing 1.2 eq acetic anhydride the N-ylides (4a-e) were produced; while the reactions of 1a, d, e yielded only N-ylides 4a, d, e, 4b, c were formed along with smaller amounts of 3b, c in the reactions of 1b, c. 3-Bromoquinoline 1-oxide (1f) gave only the N-ylide (4f) and isoquinoline 2-oxide (6) gave the 1-substituted isoquinoline (7) independently of the reaction conditions.Further, 5-alkyl-Meldrum's acids (8a-c) also reacted readily with 1a in acetic anhydride to give the corresponding 2-substituted quinolines (9a-c) in good yields.Heating of 3a, b with conc. hydrochloric acid, 10percent hydrochloric acid or methanol containing 10percent hydrogen chloride gave 2-methylquinolines (10a, b), 2-quinolineacetic acids (11a, b) or their methyl esters (12a, b), respectively.Similarly, 9a-c afforded 2-alkylquinolines (14a-c) in good yields upon being refluxed with conc. hydrochloric acid.Keywords--aromatic N-oxide; Meldrum's acid; 5-(2-quinolyl)-Meldrum's acid; quinolinium-5-Meldrum's acid ylide; 5-(1-isoquinolyl)-Meldrum's acid; 2-alkylquinoline; 2-quinolineacetic acid; nucleophilic reaction; regioselectivity
- Yousif, Mohammed Mohammed,Saeki, Seitaro,Hamana, Masatomo
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p. 1680 - 1691
(2007/10/02)
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