Ethanol → 5-(2-Bromophenyl)-3-methyl-1,2,4-oxadiazole

Participants

Reaction Steps

To activated molecular sieves (2.0 g, 4 Å powdered) was added ethanol (20 ml) followed by sodium metal (0.435 g, 18.9 mmol), and the mixture heated at reflux for 15 min. After cooling to ambient temperature, acetamide oxime (1.4 g, 18.9 mmol) was added and the suspension stirred for 15 min. Methyl 2-bromobenzoate (1.32 ml, 9.5 mmol) was added and the mixture heated at reflux for 2 h. The reaction was poured into water and extracted with ethyl acetate. The organic phase was separated, dried over magnesium sulfate, filtered and evaporated to give a white solid. The crude product was purified by crystallisation from ethyl acetatelisohexane to give 5-(2-bromophenyl)-3-methyl-[1,2,4]oxadiazole as a white solid (0.76 g): δH (400 MHz, CDCl3) 2.52 (3H, s), 7.45 (2H, m), 7.76 (1H, dd, J 7.8 and 1.2), 7.97 (1H, dd, J 7.8 and 1.2); m/z (ES+) 239:241 (1:1) (M++H).

Provenance & Evidence