Optical sensing of sulfate by polymethinium salt receptors: colorimetric sensor for heparin

Tomáš Bříza, Zdeněk Kejík, Ivana Císařová, Jarmila Králová, Pavel Martásek, Vladimír Král
2008 Chemical Communications  
Synthetic strategy Our syntetic strategy was based on our preliminary results. Bříza, T.; Kejík, Z.; Vašek, P.; Králová, J.; Martásek, P.; Císařová, I.; Král, V. Org. Lett. 2005, 17, 3661-3664 We have used derivatives of benzothiazolium iodide 2, 4 and 5, which were reacted with para-nitrophenylmalondialdehyde 6. In the first step, there was necessary to prepare the salts 2 and 4 5-hydroxy-2-methyl benzothiazole was reacted with propyl iodide under 100 °C for 3 days and corresponding iodonium
more » ... lt 2 was obtained in yield 84 %. In case of salt 4 at first, the hydroxybenzothiazole 1 was substituted with triethylene glycol chain by means of triethyleneglycol tosylate in presence of sodium hydride in dimethylformamide. The substitution afforded product 3 in high yield 91 %. Benzothiazole 3 was then treated with propyl iodide at 100 °C to obtain salt 4 in 68 % yield. Carefull NMR analysis confirmed the same geometry of the compound 7 in solution as well as in solit state. The analysis was based on NOE experiment. The assignment of individual hydrogens was accomplished by means of 1 H-NMR, 13 C-NMR, COSY, and NOE experiment. Assignment of hydrogens according 1 H NMR spectra. Compound 7 NO 2 N
doi:10.1039/b718492a pmid:18401512 fatcat:ogyfgkii4re5bk46nw2rtkwd2a