反应详情

温度

-5 °C

Acetic anhydride (10 mL) at −10° C. was treated with concentrated nitric acid (>69% pure, 1 mL) and then treated portionwise with 2-chloro-4-methoxy-1-methylbenzene (0.78 g, 5 mmol) at a rate that maintained the internal temperature lower than −5° C. The solution was stirred for additional one hour while warming to room temperature, poured into an ice and water mixture, and extracted with ethyl acetate several times. The organic layers were combined, washed with 10% Na2CO3 and brine, dried (MgSO4), and concentrated under vacuum. The residue was purified by flash column chromatography on silica gel eluting with 9:1 hexanes/ethyl acetate to provide 0.75 g (71%) of the desired product. MS (DCI) m/e 219 (M+NH4)+; 1H NMR (CDCl3, 300 MHz) δ 7.78 (s, 1H), 7.09 (s, 1H), 3.94 (s, 3H), 2.35 (s, 3H).

1. temperaturewhile warming to room temperature
2. extractionextracted with ethyl acetate several times
3. washwashed with 10% Na2CO3 and brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated under vacuum
6. customThe residue was purified by flash column chromatography on silica gel eluting with 9:1 hexanes/ethyl acetate