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U ovom radu opisana je sinteza novih derivata benzoksazola i njihova strukturna karakterizacija 1H- i 13C-NMR spektroskopijom. Reakcijom 4-hidroksibenzaldehida i odgovarajućih alkilirajućih reagenasa pripravljeni su O-alkilirani benzaldehidi (1-6) kao prekurosri koji su zatim s različito supstituiranim ortho-aminofenolima prevedeni u derivate Schiffovih baza (7-19). Oksidativnom ciklizacijom Schiffovih baza sintetizirani su derivati benzoksazola (20-32). Mikrovalno potpomognutim O-propargiliranjem 4-(5-metoksibenzo[d]oksazol-2-il)fenola (32) s propargil-bromidom uz kalijev karbonat kao bazu sintetiziran je 5-metoksi-2-(4-(prop-2-in-1-iloksi)fenil)benzo[d]oksazol (33) koji je potom klik reakcijom 1,3-dipolarne cikloadicije katalizirane bakrovim(I) jodidom s prethodno dobivenim azidima (34-36) preveden u 1,2,3-triazolne derivate benzoksazola (37-39). Strukture svih novopripravljenih derivata benzoksazola potvrđene su 1H- i 13C-NMR spektroskopijom. This work describes the synthesis of new benzoxazole derivatives and their structural characterization by 1H- and 13C-NMR spectroscopy. The reaction of 4-hydroxybenzaldehyde and the corresponding alkylating reagents prepared O-alkylated benzaldehydes (1-6) as precursors which were then converted into derivatives of Schiff bases (7-19) with variously substituted ortho-aminophenols. Oxidative cyclization of Schiff bases benzoxazole derivatives (20-32) were synthesized. Microwave-assisted O-propargylation of 4-(5-methoxybenzo[d] oxazol-2-yl)phenol (32) with propargyl bromide using potassium carbonate as a base synthesized 5-methoxy-2-(4-(prop-2)-in-1-yloxy)phenyl)benzo[d]oxazole (33) which was then converted to 1,2,3-triazole benzoxazole derivatives (37-39) by the click reaction of 1,3-dipolar cycloaddition catalyzed by copper (I) iodide with previously obtained azides (34-36). The structures of all newly prepared benzoxazole derivatives were confirmed by 1H- and 13C-NMR spectroscopy. |
