反应详情

A solution of freshly prepared sodium methoxide (6.41 g, from 2.3 g of Na) in 100 ml of methanol was added to a solution of N-(aminosulfonyl)-DL-valine methyl ester (10.5 g; 0.05 mmol) in methanol (150 ml) and the resulting reaction mixture was stirred for 6 hours. The mixture was cooled, neutralized with BIO-RAD® 50W-X8 H+ ion exchange resin, and filtered. The filtrate was concentrated in vacuo to yield a solid residue which was crystallized from methanol/hexane to afford 16.4 g of a crude 4-isopropyl-1,2,5-thiadiazolidin-3-one 1,1-dioxide (Formula IV: R1 =H R2 =isopropyl, R3 =H).

1. customthe resulting reaction mixture
2. temperatureThe mixture was cooled
3. filtrationfiltered
4. concentrationThe filtrate was concentrated in vacuo
5. customto yield a solid residue which
6. customwas crystallized from methanol/hexane