Synthesis and electronic spectra of 3‐hetaryl substituted coumarin derivatives 7‐hydroxy‐2H‐chromen‐2‐on and 9‐hydroxy‐2H‐benzo(f)chromen‐2‐on

Abstract

The synthesis of 3‐hetaryl substituted coumarin derivatives [7‐hydroxy‐2H‐chromen‐2‐on and 9‐hydroxy‐2H‐benzo(f)chromen‐2‐on] containing a hydroxyl group by reacting 2,4‐dihydroxybenzaldehyde and 2,4‐dihydroxynaphtaldehydes with 2‐cyanomethylbenzothiazole, 2‐cyanomethylbenzimidazole, 1‐methyl‐2‐cyanomethylbenzimidazole and 2‐cyanomethyl‐4‐phenylthiazole is presented. The absorption and steady‐state fluorescence characteristics of the synthesised 3‐hetaryl substituted 7‐hydroxy‐2H‐chromen‐2‐on and 9‐hydroxy‐2H‐benzo(f)chromen‐2‐on in a solution of ethanol and at different pH values are studied to assess their possible application as fluorescent probes for use in molecular biology and medicine.

New 3‐(Heteroaryl)‐2‐iminocoumarin‐based Borate Complexes: Synthesis, Photophysical Properties, and Rational Functionalization for Biosensing/Biolabeling Applications

“…We first focused on the synthesis of BF 2 complexes of known 3-(2-benzimidazolyl)-and 3-(2-benzothiazolyl)-7-hydroxy-2-iminocoumarins [14,15] (Scheme 2, left). This was achieved by treatment of these N,N-bidentate coumarinic ligandsw ith al arge excess of BF 3 ·Et 2 O( 10 equiv,a cting as both reagenta nd solvent) and 5equiv of triethylamine (TEA) and heating under reflux for 2-3 h. The resulting "Borico" dyes were isolated in good yields of 85 %b yf lash columnc hromatography on regulars ilica gel (for 1)o rr ecrystallization from CH 3 CN (for 2).…”

“…Aqueous buffers (PBS, aqueous 0.1 m acetate, and borate buffers used for thiolysis fluorescence assay and phenol pK a determination) and mobile phases for HPLC were prepared with water purified by means of aMilliQ system (purified to 18.2 MW cm). Triethylammonium acetate (TEAA, 2.0 m)a nd triethylammonium bicarbonate (TEAB, 1.0 m)b uffers were prepared from distilled TEA and glacial acetic acid or CO 2 gas, respectively.T he following starting materials were synthesized according to literature procedures:3 -(2-benzothiazolyl)-7-hydroxy-2-iminocoumarin, [14] 3-(2-benzimidazolyl)-7-hydroxy-2-iminocoumarin, [15] 3-(2-benzothiazolyl)-7-hydroxy-2-iminocoumarin-6-sulfonic acid, [12,17] tert-butyl 4-aminobenzylcarbamate, [36] and sodium thiophosphate (NaThioPi). [37] DOTA-NHS was synthesized and provided by the CheMatech company (Dijon, France).…”

Dual enzyme-responsive “turn-on” fluorescence sensing systems based on in situ formation of 7-hydroxy-2-iminocoumarin scaffolds

“…[23][24][25] See ESI † for the synthesis of Ac--PHBA and PhAc--PABA. [23][24][25] See ESI † for the synthesis of Ac--PHBA and PhAc--PABA.…”

Synthesis of novel water‐soluble fluorescent coumarins bearing sulphonic and hydroxyl groups

“…Going from ethanol to water, the position of the longest wavelength absorption band does not effectively change; this provides indirect evidence to support the idea that the addition of a sulphonic group to the coumarin moiety does not change the photophysical properties of the dyes [24,25] and that they might be used as water-soluble derivatives of coumarins. Going from ethanol to water, the position of the longest wavelength absorption band does not effectively change; this provides indirect evidence to support the idea that the addition of a sulphonic group to the coumarin moiety does not change the photophysical properties of the dyes [24,25] and that they might be used as water-soluble derivatives of coumarins.…”