Influence of trimethoxy-substituted positions on fluorescence of heteroaryl chalcone derivatives

Abstract

Three series of heteroaryl chalcones, (E)-1-(2-pyridyl)-3-(X)prop-2-en-1-one (Ia-Ic), (E)-1-(2-thienyl)-3-(X)prop-2-en-1-one (IIa-IIc), and (E)-1-(2-furyl)-3-(X)prop-2-en-1-one (IIIa-IIIc), where X = 2,4,5-trimethoxyphenyl (for series a), X = 2,4,6-trimethoxyphenyl (for series b), and X = 3,4,5-trimethoxyphenyl (for series c) were synthesised using basic catalysed aldol condensation and characterised using 1H NMR and FT-IR spectroscopies. Compound IIa was also characterised by single crystal X-ray analysis. The absorption and fluorescence emission spectra of these compounds revealed that the absorption and fluorescence depended on the heterocycle rings and trimethoxysubstituted phenyl rings linked to the enone system. The position of methoxy groups substantially affected the fluorescent properties. Compounds Ia-IIIa containing the 2,4,5-trimethoxyphenyl moiety exhibited the red-shift phenomenon and strong emission fluorescence.

Synthesis, Cyclooxygenase Inhibition, Anti‐Inflammatory Evaluation, and Ulcerogenic Liability of New 1,3,5‐Triarylpyrazoline Derivatives Possessing a Methanesulfonyl Pharmacophore

“…The propen‐1‐one derivatives ( 11a–l ) were prepared via base catalyzed condensation of the appropriate aromatic aldehyde and the corresponding ketone in methanol using reported procedures . Cyclocondensation of the appropriate chalcone ( 11a–l ) with 4‐methanesulfonylphenylhydrazinehydrochloride ( 12 ) in aqueous ethanol afforded the respective triarylpyrazolines ( 13a–l ) as racemic mixtures in good yields (62–88%) (Scheme ).…”

“…All other reagents, purchased from the Acros Chemical Company, were used without further purification. The propen‐1‐one derivatives ( 11a–l ) and 4‐methanesulfonylphenylhydrazine hydrochloride ( 12 ) were prepared according to reported procedures.…”

1,5-Bis(thiophen-2-yl)-3-(2,4,5-trimethoxyphenyl)pentane-1,5-dione

“…The title compound (I) is a symmetrical 1,5-diketone compound which was alternatively synthesized by the stirring of (E)-1-(2-thitenyl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (0.57 g, 1.5 mmol) (Suwunwong et al, 2011) in methanol (15 ml) with a freshly prepared sodium methoxide (1.5 mmol of sodium in 40 ml of methanol). Excess malononitrile (0.20 g, 3.0 mmol) was then added with continuous stirring at room temperature until the precipitate separated out.…”

“…For background and applications of 1,5-diketone compounds, see: Alagarsamy et al (2007); Favaro et al (2002); Harrowven & Hannam (1999); Pillai et al (2004); Rai et al (2008). For the preparation of the title compound, see: Suwunwong et al (2011). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 Table 1 Hydrogen-bond geometry (Å , ).…”

(E)-1-(Furan-2-yl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one

“…For background to and applications of chalcones, see: Cheng et al (2008); Jung et al (2008); Lee et al (2006); Liu et al (2011); Nerya et al (2004); Suwunwong et al (2011); Tewtrakul et al (2003). For related structures, see: Fun et al (2010aFun et al ( ,b, 2011.…”