Reaktion #60563

Reaktionsgleichung

methyl iodide

2-hydroxy-4-nitro-benzoic acid methyl ester

sodium hydride

→

2-methoxy-4-nitro-benzoic acid methyl ester

Ausbeute 47.4%

Lösungsmittel

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturis heated for 1 hour to 50° C
2. 2
   Temperaturheated for 4 hours to a bath temperature of 80° C
3. 3
   EinengenAfter concentration
4. 4
   Sonstigeby evaporation, it
5. 5
   Extraktionextracted three times with 25 ml each of ethyl acetate
6. 6
   WaschenThe ethyl acetate phase is washed with water
7. 7
   Sonstigedried
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated by evaporation
10. 10
    SonstigeThe residue is chromatographed on 5 g of Isolute SI

Vorschrift

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.

Quelle