Dibenzoate5-(ethylsulfone)-2-(naphthalen-2- yl)benzo[d]oxazole (Ezotrumid) 5a:
5- (ethylthio)-2-(naphthalen-2-yl)Benzo[d]oxazole (30.5 mg, 0.1 mmol), UO2(OAc)2 . 2H2O (0.8 mg, 0.002 mol), H2O (10 equiv., 36 μL), o-xylene (8.3 equiv., 0.2 mL), CH3CN (1 mL) were stirred under oxygen atmosphere (1 atm, balloon) at room temperature until the total consumption of sulfide and sulfoxide under the irradiation of three 2 w blue LEDs in a paralleled reactor. 5a (27.3 mg, 81%) was obtained through column chromatography (PE/EA = 20/1-5/1) as a white solid, Rf = 0.6 (PE/EA = 2/1);
1H NMR (500 MHz, Chloroform-d) δ 8.82 (s, 1H), 8.37 (s, 1H), 8.32 (d, J = 8.5 Hz, 1H), 8.02 (d, J = 8.0 Hz, 2H), 7.99 – 7.89 (m, 2H), 7.84 – 7.76 (m, 1H), 7.61 (t, J = 7.3 Hz, 2H), 3.28 – 3.08 (m, 2H), 1.32 (dt, J = 7.3, 3.6 Hz, 3H)..
13C NMR (126 MHz, Chloroform-d) δ 165.57, 153.87, 142.86, 135.26, 135.14, 132.86, 129.09, 128.97, 128.37, 127.99, 127.19, 125.35, 123.87, 123.34, 121.00, 111.36, 51.04, 7.62.
IR (KBr) 2933, 1507, 1498, 1258, 1064, 1046, 756, 474 cm-1 .
HRMS (ESI) Calcd for C19H16NO3S 338.0851 (M+H), Found 338.0865.
