反应详情

To a solution of 2 mmol of the diester obtained in Example 1 (step D) dissolved in a THF/H2O (75/25) mixture, are added, at 0° C. and under an argon atmosphere, 8 mmol of LiOH with stirring for 2 hours. The THF is evaporated off and the aqueous phase is washed with ether and acidified with aqueous 3N HCl solution. It is extracted with ether and the ether extract is washed with saturated aqueous NaCl solution and dried over MgSO4. It is filtered and evaporated. Yield: 63% (after flash chromatography, eluent: ether) m.p. 80° C. IR (nujol): 3340, 1700, 1630, 1610 cm-1. 1H NMR (acetone D6): 10.90 to 10.60 (m, 1H); 7.65 (m, 1H); 7.45 to 7.35 (m, 5H); 7.20 (s, 1H); 3.75 to 3.50 (m, 4H); 2.60 (t, 2H, J=6.75 Hz); 2.30 (t, 1H, J=7.50 Hz) Microanalysis: C13H15O3NS Calc. % C=58.85 H=5.70 N=5.28 Found. % C=58.68 H=5.78 N=5.17

1. additionare added, at 0° C. and under an argon atmosphere
2. customThe THF is evaporated off
3. washthe aqueous phase is washed with ether
4. extractionIt is extracted with ether
5. extractionthe ether extract
6. washis washed with saturated aqueous NaCl solution
7. dry with materialdried over MgSO4
8. filtrationIt is filtered
9. customevaporated