Sodium hydride → 3-Methyl-5-(2-hydroxy-styryl)-isoxazole

Reaktionsgleichung

[H-].[Na+].[CH3:3][C:4]1[CH:8]=[C:7]([CH2:9]P(OCC)(=O)OCC)[O:6][N:5]=1.COC([O:22][C:23]1[CH:30]=[CH:29][CH:28]=[CH:27][C:24]=1[CH:25]=O)C>CS(C)=O>[CH3:3][C:4]1[CH:8]=[C:7]([CH:9]=[CH:25][C:24]2[CH:27]=[CH:28][CH:29]=[CH:30][C:23]=2[OH:22])[O:6][N:5]=1

Komponenten

Versuchsvorschrift

8.8 g (0.2 mole) of a 55% strength suspension of sodium hydride in paraffin oil are introduced into 100 ml of absolute dimethylsulfoxide. 47 g (0.2 mole) of diethyl (3-methyl-isoxazol-5-yl)-methanephosphonate are added dropwise at room temperature. The mixture is then stirred for 30 minutes, after which 36 g (0.2 mole) of o-(1-methoxyethoxy)-benzaldehyde are added dropwise, with continued stirring. The reaction mixture is then stirred for 24 hours at room temperature and is poured onto 1 liter of ice water, and the batch is extracted 3 times with 80 ml of methylene chloride at a time. The combined organic phases are dried with sodium sulfate and evaporated down on a rotary evaporator. The oily residue is dissolved in 80 ml of methanol and 10 ml of water, 2 ml of 5 N HCl are added, and the mixture is stirred for 10 minutes. Excess water is then added slowly until a precipitate forms. This is filtered off, washed with water and recrystallized from ethanol. 19 g (47% of theory) of colorless crystals, of melting point 236°-238° C., are obtained.