| 摘要 |
PURPOSE: Title compounds are prepared which are useful as an intermediate of pharmaceutical compound. CONSTITUTION: Title compounds (formula 1; R1 is lower alkyl or lower cycloalkyl group; R2 is bound by N atom, contained or not N, O and (or) S, SO or SO2 as a supplemental ring; one or two carbon atoms adjacent in N atom are substituted by oxo) are prepared. Thus, 5.6 g of potassium hydroxide, 71.1 g of 1,5,5-trimethyl-imidazolidin-2,4-dione and 78.1 g of (RS)-2-tert-buthoxymethyl-oxime are reacted at 70 degree C for 4 hours, cooled to room temperature. Obtained product and 20.0 g of potassium bicarbonate are added in 11.2 ml of 48 % hydrobromic acid and 500 ml of dichloromethane, cooled to 0 degree C. 0.4 g of 2,2,6,6-Tetramethyl-piperidine-1-oxyl is added in the solution, followed by the addition of 472 g of 10.5 % aqueous sodium hypochlorite at 0 degree C for 2 hours, at 0 degree C for 0.5 hour to give 122.8 g of 3-(3-tert-buthoxy-2-oxo-propyl)-1,5,5-trimethyl-imidazolidin-2,4-dione.
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