Water → 3-[8-(3-Methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-4-yl]-propionic acid

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Reaction Steps

In 40 ml of dioxane was dissolved 4.11 g of benzyl 3-[8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-4-yl]-propionate. Then, 20.5 ml of 1 mol/L aqueous solution of sodium hydroxide was added at 0-5° C., and the resulting mixture was stirred at ambient temperature for one hour. The reaction mixture was poured into a mixture of chloroform and water, the aqueous layer was separated, ethyl acetate was added to the aqueous layer, 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. Purification of the residue by column chromatography (eluent: chloroform:ethanol=50:1) gave 2.72 g of 3-[8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-4-yl]-propionic acid as a light yellow oily product.

Provenance & Evidence