反应详情

温度

0 °C

Dissolve 5-nitro-3H-benzooxazole-2-thione (10.58 g, 53.9 mmol) in anhydrous THF (300 mL). Cool the mixture to 0° C. in an ice bath. Add NaH (4.90 g, 60% dispersion in mineral oil) slowly. Stir the resulting mixture at 0° C. for 10 min. Add iodoethane (20.0 mL, 0.250 mmol) to the stirring mixture. Allow the mixture to warm to room temperature and stir overnight. Adsorb the reaction mixture onto silica gel and subject to flash column chromatography in 2 batches (330 g, 120 g columns, eluting with 10-50% ethyl acetate/n-hexane both times) to yield the desired product (4.93 g, 41%). 1H NMR (400 MHz, DMSO-d6): δ 8.47 (d, J=2.4 Hz, 1H), 8.23 (dd, J=9.2, 2.6 Hz, 1H), 7.88 (d, J=8.8 Hz, 1H), 3.37 (q, J=6.8 Hz, 2H), 1.45 (t, J=7.6 Hz, 3H).

1. temperatureAllow the mixture to warm to room temperature
2. stirringstir overnight
3. washeluting with 10-50% ethyl acetate/n-hexane both times)