Trifluoroacetic acid → 3-(2-(Methylthio)ethyl)piperazin-2-one

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Reaction Steps

Trifluoroacetic acid (30 ml.) is added at 0° to a stirred solution of 4-t-butoxycarbonyl-3-[2-(methylthio)ethyl]piperazinone (XVII, Example 43, 2.6 g., 0.0095 mole) in diethyl sulfide (20 ml.). After 1 hour the solvents are removed and the residual oil is partitioned between chloroform (300 ml.) and 5N sodium hydrochloride solution (10 ml.). The chloroform is washed with water (2×10 ml.) and the chloroform is removed under reduced pressure. The residual oil is chromatographed on silica gel eluted with methanol:chloroform (1:9), the appropriate fractions are pooled and concentrated to give a solid which upon recrystallization from ethyl acetate:SSB gives the title compound, m.p. 68°-70°.

Provenance & Evidence