反应详情

温度

70 °C

A round bottom flask was charged with 4-chloro-2-methylbenzoic acid (200 mg, 0.001 mol) and sulfuric acid (1 mL, 0.02 mol) and fuming nitric acid (0.05 mL, 0.001 mol) was added at −20° C. and the reaction stirred for 1 hour at 70° C. and poured into ice cold water wherein the mixture of 2- and 4-nitro compounds precipitated out. The precipitate was filtered and dissolved in ethylacetate (30 mL) and washed with saturated aqueous sodium bicarbonate solution, brine and dried over sodium sulfate. The solvent was reduced ¼ volume, and the undesired isomer precipitated out. The precipitate was filtered and the filtrate was dried to obtain a 1:1 mixture of isomers as a white solid. MS m/z=214.5 (M−H).

1. additionwas added at −20° C.
2. additionpoured into ice cold water wherein
3. customprecipitated out
4. filtrationThe precipitate was filtered
5. dissolutiondissolved in ethylacetate (30 mL)
6. washwashed with saturated aqueous sodium bicarbonate solution, brine
7. dry with materialdried over sodium sulfate
8. customthe undesired isomer precipitated out
9. filtrationThe precipitate was filtered
10. customthe filtrate was dried
11. customto obtain
12. additiona 1:1 mixture of isomers as a white solid