Hydrochloric Acid → Isopropyl 2-[4-[2-(tert-butoxy)-2-oxoethyl]-8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-2-yl]-acetate

Participants

Reaction Steps

In 10 ml of N,N-dimethylformamide was dissolved 1.0 g of 2-[4-[2-(tert-butoxy)-2-oxoethyl]-8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-2-yl]-acetic acid. After adding 0.42 ml of 2-iodopropane and 0.67 g of anhydrous potassium carbonate at ambient temperature, the resulting mixture was stirred at ambient temperature for 17 hours. 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 thus obtained was washed successively with water, saturated aqueous solution of sodium hydrogen carbonate 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: hexane:ethyl acetate=17:3] gave 1.0 g of isopropyl 2-[4-[2-(tert-butoxy)-2-oxoethyl]-8-(3-methylbutylidene)-3-oxo-1-thia-4-azaspiro[4.5]decan-2-yl]-acetate as a light yellow oily product.

Provenance & Evidence