反应详情

温度

-70 °C

In an atmosphere of nitrogen, 1.97 ml of N,N-diisopropylamine was added to 10 ml of anhydrous tetrahydrofuran, to which was dropwise added 9.50 ml of a solution of n-butyllithium in hexane (1.58 mol/L) at −30° C. The mixture was stirred at the same temperature for 10 minutes and then cooled to −70° C., to which was dropwise added a solution of 1.56 g of 3-[8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-4-yl]-propionic acid in 20 ml of anhydrous tetrahydrofuran. After stirring the resulting mixture at the same temperature as above for 30 minutes, 0.89 ml of tert-butyl bromoacetate was dropwise added at the same temperature. After elevating the temperature to 0° C., the reaction mixture was poured into a mixture of ice water and ethyl acetate, pH was adjusted to 2.0 with 2 mol/L hydrochloric acid, and the organic layer was separated. The organic layer was washed successively with water and saturated aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. Thus, 2.23 g of 3-[2-[2-(tert-butoxy)-2-oxoethyl]-8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-4-yl]-propionic acid was obtained as a yellow oily product.

1. customat −30° C
2. additionwas dropwise added at the same temperature
3. customto 0° C.
4. customthe organic layer was separated
5. washThe organic layer was washed successively with water and saturated aqueous solution of sodium chloride
6. dry with materialdried over anhydrous magnesium sulfate
7. distillationthe solvent was distilled off under reduced pressure