反应详情

The crude 6-ethoxy-5,6-dihydro-2-[3-(trifluoromethyl)phenyl]-4H-1,3,4-oxadiazine-4-carboxylic acid ethyl ester (17 g) from Step C above, was mixed with 12 g of KOH, 20 g of ethanol, and 40 g of water to create a reaction mixture. The reaction mixture was refluxed for 6 hours and then cooled. 50 ml of water was then added to the reaction mixture, followed by extraction with ethyl acetate (4×100 ml). The ethyl acetate extracts were conbined, dried (MgSO4) and the solvent removed, to give 7 g of crude 6-ethoxy-5,6-dihydro-2-[3-(trifluoromethyl)phenyl]-4H-1,3,4-oxadiazine, which was not purified and was used in Step E below.

1. temperatureThe reaction mixture was refluxed for 6 hours
2. temperaturecooled
3. extractionfollowed by extraction with ethyl acetate (4×100 ml)
4. dry with materialdried (MgSO4)
5. customthe solvent removed