- Reaction of some 2-quinolone derivatives with phosphoryl chloride: Synthesis of novel phosphoric acid esters of 4-hydroxy-2-quinolone
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3-Chloroquinoline-2,4-diones do not react with phosphoryl chloride, however, 2,4-dichloroquinolines and/or 4-chloroquinolin-2-ones are formed in the presence of N,N-dimethylaniline. Along with these compounds, small quantities of novel dihydrogen phosphates of 4-hydroxyquinolin-2-ones were isolated. We outline a simple procedure that allows for the preparation of these compounds in moderate to good yields. All compounds were characterized by 1H and 13C NMR, IR, EI-MS, and ESI-MS spectroscopy, and in select cases by 31P NMR spectroscopy.
- Rudolf, Ondrej,Mrkvicka, Vladimir,Lycka, Antonin,Rouchal, Michal,Klasek, Antonin
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p. E100-E110
(2013/06/04)
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- 4-Cyano-6,7-dimethoxycarbostyrils with solvent- and pH-independent high fluorescence quantum yields and emission maxima
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Highly fluorescent and stable 6,7-dimethoxy-2-oxoquinoline-4-carbonitriles (11) were synthesized starting from appropriate 4-hydroxyquinolones 3 via reactive 4-chloroquinolones 8 by using toluenesulfinates as catalysts. In contrast to the well-described 4-trifluoromethyl-substituted analogues 18, N-substituted derivatives 11 fluoresce in water, polar, and apolar solvents in a narrow 430-440-nm window with almost constant quantum yield of 0.5. Equal excitation is possible in the broad double maximum between 385 and 410 nm yielding identical data between pH 1 and 11. These properties could lead to a broadly usable fluorescence standard. N-Alkylation with bromoacetate yields ester 13 in good yields. Reactive succinimidoyl (OSu) ester 15 was prepared by saponification to acid 14. With amino acids or peptides, linking to labeled derivatives 17 was achieved under mild conditions in slightly basic aqueous media. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Ahvale, Appasaheb B.,Prokopcova, Hana,Sefcovicova, Jana,Steinschifter, Waltraud,Taeubl, Anna E.,Uray, Georg,Stadlbauer, Wolfgang
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p. 563 - 571
(2008/09/18)
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- Syntheses and binding affinities of 6-nitroquipazine analogues for serotonin transporter. Part 4: 3-Alkyl-4-halo-6-nitroquipazines
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On the basis of the structure-activity relationship (SAR) of 4-chloro-6-nitroquipazine (Ki = 0.03 nM) and 3-fluoropropyl-6- nitroquipazine (Ki = 0.32 nM), 3-alkyl-4-halo-6-nitroquipazines were synthesized and tested for their potenti
- Byung, Seok Moon,Byoung, Se Lee,Dae, Yoon Chi
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p. 4952 - 4959
(2007/10/03)
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- Regioselective Azidation of 2,4-Dichloroquinolines
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Reactions of 2,4-dichloroquinolines (2a-f) with sodium azide in DMF lead either regioselectively to 4-azido-2-chloroquinolines (3a-f) or with excess of sodium azide and catalysts to 5-azido-tetrazoloquinolines (4a-f). 2,4-Dichloroquinolines (2g-i) having electron donating substituents in 3-position react with sodium azide in DMF to a mixture of 4-azido-2-chloroquinolines (3g-i) and 5-chlorotetrazoloquinolines (5g-i).When the reaction of the 2,4-dichloroquinolines (2a-i) with sodium azide is carried out in ethanol with addition of methanesulfonic acid, regioselectively 5-chloro-tetrazoloquinolines (5a-i) are obtained.Structural assignments of 3 and 5 have been carried out by 13C-NMR spectra, IR spectra and degradation reactions of the azido- and tetrazolo group to aminoquinolines (7 and 10) via iminophosphoranes (8 and 9).It could be shown that in 2-azido/tetrazolo-quinolines (4 and 5) the tetrazole ring structure is the dominant species.
- Steinschifter, Waltraud,Stadlbauer, Wolfgang
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p. 311 - 318
(2007/10/02)
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