反应详情

50 g Of 2-(methylthio)ethanol was added dropwise over a 30-minute period to a stirred mixture of 3.0 g of 57% mineral oil dispersion of sodium hydride in 50 ml of dry dimethylformamide at 0°. The mixture was allowed to warm to room temperature and stirred for 1 hour. Then 6.1 g of 1A was added all at once and the mixture was stirred at room temperature overnight and extracted with ether and with methylene chloride. the aqueous layer was acidified and extracted with methylene chloride. The latter extract was washed with water, dried (MgSO4), decolorized and filtered and the solvent was evaporated under reduced pressure. The residue was crystallized from pentane, then recrystallized from ethyl acetate-ether to give the 2-(methylthio)ethyl ester of nitro(tetrahydro-2H-1,3-oxazin-2-ylidene)acetic acid (1B) as a pale yellow solid, m.p.: 88.5°-89.5°.

1. stirringwas stirred at room temperature overnight
2. extractionextracted with ether and with methylene chloride
3. extractionextracted with methylene chloride
4. extractionThe latter extract
5. washwas washed with water
6. dry with materialdried (MgSO4)
7. filtrationfiltered
8. customthe solvent was evaporated under reduced pressure
9. customThe residue was crystallized from pentane
10. customrecrystallized from ethyl acetate-ether