Reaktion #1944130

Reaktionsgleichung

2-[(3-methyl-4-methoxyphenyl)methylene]-6-hydroxy-3(2H)-benzofuranone

potassium carbonate

dimethylformamide

methyl p-toluenesulfonate

→

desired compound

Ausbeute 74.2%

2-[(3-methyl-4-methoxyphenyl)methylene]-6-methoxy-3(2H)-benzofuranone

Ausbeute 74.2%

Lösungsmittel

hexane

water

ethyl acetate

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   ExtraktionThe resulting compound was extracted with ethyl acetate 50 ml twice
3. 3
   WaschenThe ethyl acetate solution was washed with a saturated sodium chloride solution 50 ml twice
4. 4
   Einengenconcentrated at a temperature of 40° C. under reduced pressure
5. 5
   Sonstigeto obtain crude powder
6. 6
   WaschenThe residue was fractionated by silica gel column chromatography (silica gel: 50 g, eluted with solvent 500 ml of hexane:ethyl acetate=1:1)
7. 7
   Einengenthe fraction was concentrated to dryness at a temperature of 40° C. under reduced pressure
8. 8
   Sonstigeto obtain crystals
9. 9
   FiltrationThe precipitated crystals were filtered
10. 10
    Trocknendried over phosphorous pentoxide at a temperature of 60° C. for four hours under reduced pressure

Vorschrift

To a solution of 2-[(3-methyl-4-methoxyphenyl)methylene]-6-hydroxy-3(2H)-benzofuranone 0.477 g, potassium carbonate 0.583 g and dimethylformamide 5 ml, methyl p-toluenesulfonate 0.314 g was added. After the mixture was stirred for two hours at a temperature of 60° C., water 100 ml was added. The resulting compound was extracted with ethyl acetate 50 ml twice. The ethyl acetate solution was washed with a saturated sodium chloride solution 50 ml twice, dehydrated with anhydrous magnesium sulfate, and concentrated at a temperature of 40° C. under reduced pressure to obtain crude powder. The residue was fractionated by silica gel column chromatography (silica gel: 50 g, eluted with solvent 500 ml of hexane:ethyl acetate=1:1) and the fraction was concentrated to dryness at a temperature of 40° C. under reduced pressure to obtain crystals. The crystals were dissolved in ethyl acetate 2 ml and hexane 10 ml, and the solution was allowed to stand at room temperature for two hours. The precipitated crystals were filtered and dried over phosphorous pentoxide at a temperature of 60° C. for four hours under reduced pressure to obtain the desired compound 371.6 mg.

Quelle