反应详情

788 mg (4 mmol) of 2-hydroxy-4-nitro-benzoic acid methyl ester is mixed in 20 ml of absolute dimethylformamide with 177 mg of sodium hydride (60%; 4.4 mmol), and it is heated for 1 hour to 50° C. After cooling to room temperature, it is mixed with 625 mg (4.4 mmol) of methyl iodide and heated for 4 hours to a bath temperature of 80° C. After concentration by evaporation, it is taken up in 50 ml of water and extracted three times with 25 ml each of ethyl acetate. The ethyl acetate phase is washed with water, dried, filtered and concentrated by evaporation. The residue is chromatographed on 5 g of Isolute SI. (50 μm) with a gradient from cyclohexane to cyclohexane:ethyl acetate=80:20 as an eluant, and 400 mg (47% of theory) of 2-methoxy-4-nitro-benzoic acid methyl ester is obtained as an oil.

1. temperatureis heated for 1 hour to 50° C
2. temperatureheated for 4 hours to a bath temperature of 80° C
3. concentrationAfter concentration
4. customby evaporation, it
5. extractionextracted three times with 25 ml each of ethyl acetate
6. washThe ethyl acetate phase is washed with water
7. customdried
8. filtrationfiltered
9. concentrationconcentrated by evaporation
10. customThe residue is chromatographed on 5 g of Isolute SI