反应详情

To a 4N sodium hydroxide solution (200 mL) was added S-methylisothioureasulfate (55.6 g, 0.2 mol), and after stirring for 30 min, at room temperature a solution of diethyl ethoxymethylenemalonate (80.8 mL, 0.35 mol) in ethanol (100 mL) was dropwise added slowly over 1 h. After stirring for 18 h, the precipitated crystals were collected by filtration, washed several times with cold ethanol and the obtained crystals were added to 1N hydrochloric acid (300 mL). The mixture was stirred for 30 min and the precipitated crystals were collected by filtration, washed several times with cold water and dried with heating under vacuum to give the title compound (26 g, 61%) as crystals.

1. additionwas dropwise added slowly over 1 h
2. filtrationthe precipitated crystals were collected by filtration
3. washwashed several times with cold ethanol
4. additionthe obtained crystals were added to 1N hydrochloric acid (300 mL)
5. stirringThe mixture was stirred for 30 min
6. filtrationthe precipitated crystals were collected by filtration
7. washwashed several times with cold water
8. customdried
9. temperaturewith heating under vacuum