反应详情

To a conc. H2SO4 (90 mL) was added portionwise 5-chloro-2-methylbenzoic acid (13.2 g, 77.6 mmol) at −5-0° C. Then a mixture of conc. HNO3 (10.5 g, 1744 mmol) in conc. H2SO4 (15 mL) was added dropwise at −5-0° C. over a period of about 1.5 hr. After the addition, the mixture was stirred at this temperature for 2 hr. The mixture was poured into crashed ice with vigorous stirring and the precipitate was collected by filtration. The precipitate was dissolved in EtOAc, washed with brine, dried over anhydrous Na2SO4, and concentrated to give a crude title compound (13.2 g), which was used in the next step without further purification.

1. additionwas added dropwise at −5-0° C. over a period of about 1.5 hr
2. additionAfter the addition
3. additionThe mixture was poured
4. stirringwith vigorous stirring
5. filtrationthe precipitate was collected by filtration
6. dissolutionThe precipitate was dissolved in EtOAc
7. washwashed with brine
8. dry with materialdried over anhydrous Na2SO4
9. concentrationconcentrated