反应详情

Sec-Butyl lithium (9.25 ml of 1.35 M solution in cyclohexane) was added to a stirred solution of (S)-3-[[(1,1-dimethylethoxy)carbonyl]amino]-2-oxoazetidine (2.33 g) in 250 ml of dry tetrahydrofuran at -75° C. under nitrogen. After stirring for 2 minutes, (methylsulfonyl)-isothiocyanate (1.75 ml) was added, and the solution was stirred for 25 minutes at -75° C. and poured into 125 ml of 0.5 M pH 5.5 monobasic potassium phosphate buffer. Ethyl acetate and water were added, and the pH was adjusted to 2.5 (3N hydrochloric acid). The ethyl acetate layer was washed with water, dried with sodium sulfate, and evaporated to a residue (3.69 g), which was recrystallized from ethyl acetate to give 2.04 g of the title compound. Recrystallization of a portion from ethyl acetate gave crystals, melting point 181° C.,dec.

1. stirringthe solution was stirred for 25 minutes at -75° C.
2. washThe ethyl acetate layer was washed with water
3. dry with materialdried with sodium sulfate
4. customevaporated to a residue (3.69 g), which
5. customwas recrystallized from ethyl acetate