[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][C:11]([C:13]([O:15]C)=[O:14])=[CH:12][C:7]=2[S:6][C:5]2[CH:17]=[CH:18][CH:19]=[CH:20][C:4]=2[NH:3]1.[OH-].[Na+]>O1CCCC1>[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][C:11]([C:13]([OH:15])=[O:14])=[CH:12][C:7]=2[S:6][C:5]2[CH:17]=[CH:18][CH:19]=[CH:20][C:4]=2[NH:3]1Dissolve 1.49 gm of the ester of Example 2 in 50 cc of tetrahydrofuran. Add 40 cc of 10% sodium hydroxide and stir at room temperature for 3 hours. Evaporate the tetrahydrofuran and extract the aqueous residue with ethyl acetate. Acidify and separate the precipitate by filtration. Wash the precipitate well with water and dry in vacuo to obtain the title product (m.p. 362°-364° C.).
불러오는 중…