反应详情

To 143 mg of 8-ethoxy-4-hydroxy-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-2-one in 1 ml of tetrahydrofuran are added 36 □l of pyridine and 53 □l of pivaloyl chloride. After stirring at room temperature for 20 hours, water and ethyl acetate are added and the phases separated. The aqueous phase is extracted with ethyl acetate, the combined organic phases dried with sodium sulfate, filtered and concentrated. Chromatography (heptane/ethyl acetate 2:1) yielded 117 mg of 2,2-dimethyl-propionic acid 8-ethoxy-2-oxo-3-(2,4,6-trimethyl-phenyl)-1,8-diaza-spiro[4.5]dec-3-en-4-yl ester as a solid, mp: 230-231° C.

1. customthe phases separated
2. extractionThe aqueous phase is extracted with ethyl acetate
3. dry with materialthe combined organic phases dried with sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated