The synthesis of novel crown ethers, part ix, 3‐phenyl chromenone‐crown ethers

Abstract

3-Phenyl-and 3-(p-methoxyphenyl)-7,8-dihydroxy and -6,7-dihydroxychromenones were prepared from ethyl 3-oxo-2-phenylpropanoate, ethyl 3-oxo-2-(4-methoxyphenyl)-propanoate and the trihydroxy benzenes in H 2 SO 4 . 3-Aryl-7,8-and 3-aryl-6,7-dihydroxy-2H-chromenones reacted with the bis-dihalides of polyglycols in DMF/MeCO 3 to afford 12-Crown-4, 15-Crown-4 and 18-Crown-6-chromenones. The products were identified with IR, 1H NMR, low and high resolution mass spectroscopy and elemental analysis. Some 1:1 cation association constants, K b , of the 3-phenyl chromenone crown ethers with Li + , Na + , K + and Rb + cations were studied by steady state emission fluorescence spectroscopy; K b chromenone-crown complexes displayed crown ether-cation binding selectivity rules properly in acetonitrile.

The synthesis of novel crown ethers, part X, 4‐propyl‐and 3‐ethyl‐4‐methylchromenone‐crown ethers

“…Compound 1a (3.15 g, 25 mmol) and 2b (3.96 g, 25 mmol) and CF 3 COOH, (20 mL, 99%) were placed in a flask (50 ml), refluxed for 6 h and then kept overnight at -10 o C. The raw product was collected by filtration, washed with water and dried under vacuum to afford 3b, 1 In a reaction flask (100 mL), 3b (1.10 g, 5.0 mmol), 4a (0.94 g, 5.0 mmol), Na 2 CO 3 (1.06 g, 10.0 mmol) and DMF (25 mL) were placed and heated at 70-80 o C for 70-80 h while stirring, then acidified (HCl, 2 %, 40 mL) and collected by filtration. The dissolved crude product, dissolved in CHCl 3 (25 mL), was purified by column chromatography ( 20-Ethyl-21-methyl-2, 3,5,6,8,9,11,12,14,15-nonahydro-18H- [1,4,7,10,13,16]hexaoxacyclo-octadecino[2,3-g]chromen-18one (5c).…”

“…We have previously synthesised various crown ethers and podands with different chromophore moieties and reported their cation-complex formation stabilities using steady state fluorescence spectroscopy in acetonitrile [9][10][11][12][13]. The macrocyclic ether derivatives of the 3-phenyl, 4-H, 4-methyl-6,7-dihydroxy-as well as -7,8-dihydroxycoumarins synthesised recently showed selective cation binding effects with steady state fluorescence emission spectroscopy.…”

A comparison for application time of electrical discharge onto 3-acetamidocoumarin molecule

“…Natural products like esculetin, fraxetin, daphnetin and other related coumarin derivatives are also recognised to possess anti-inflammatory as well as anti-oxidant activities. Coumarins and coumarin derivatives are also currently used in perfumes and agrochemicals production [25][26][27][28][29][30][31].…”

The synthesis of chromophore ended glycoles, part IV. Bis-coumarin derivatives ended polyglycols

“…Fluorescent supramolecules with strong polar groups are fast and practical for remote detection of cationic and molecular interactions [6][7][8]. The synthesis and the ionic recognition properties of the synthetic receptors of macrocyclic ethers and their noncyclic polyoxa initials with chromophore moieties have been our work of interest [8][9][10][11][12][13][14]. On the other hand, cation selectivity is the prime importance that very much depends on the analytical method [1][2][3].…”

“…Coumarins isolated from plants could be synthesized. Using the coumarin substituted crown ethers studied with steady state fluorescence spectroscopy significant results have been obtained [9][10][11]. Hydroxy coumarins were condensed with ketoesters in HCIO 4 , H 2 SO 4 or different methods [19].…”