反应详情

N-(3-Acetylthio-2-methylpropanoyl)-N-cyclopentylglycine t-butyl ester (80.1 g, 0.23 mol), trimethylsilyl chloride (37.9 g, 0.35 mol), and sodium iodide (52.5 g, 0.35 mol) were added to acetonitrile (300 ml), and the reaction mixture was stirred at 45° C.-50° C. for 30 minutes. Water (50 ml) was then added and the mixture was concentrated. The residue was dissolved in saturated aqueous sodium bicarbonate (400 ml) and was washed with ethyl acetate (3×400 ml). The aqueous portion was separated, acidified (conc. hydrochloric acid), and extracted with ethyl acetate. The organic extracts were combined, dried over Na2SO4 and MgSO4, filtered and concentrated yielding the crude desired product as a brown oil (60 g, 90%). When this material was eluted through a high pressure liquid chromatography column with ethyl acetate/hexane/acetic acid (60:40:2) a slightly yellow oil was obtained. This compound was characterized as its DCHA salt which was prepared by adjusting to pH 9 an acetonitrile solution of the compound with DCHA. The salt was obtained as a white crystalline solid, m.p, 172°-174° C.

1. concentrationthe mixture was concentrated
2. dissolutionThe residue was dissolved in saturated aqueous sodium bicarbonate (400 ml)
3. washwas washed with ethyl acetate (3×400 ml)
4. customThe aqueous portion was separated
5. extractionextracted with ethyl acetate
6. dry with materialdried over Na2SO4 and MgSO4
7. filtrationfiltered
8. concentrationconcentrated