[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[S:6][C:5]2[CH:13]=[C:14]([C:17]([OH:19])=[O:18])[CH:15]=[CH:16][C:4]=2[NH:3]1.O1CCC[CH2:21]1>>[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[S:6][C:5]2[CH:13]=[C:14]([C:17]([O:19][CH3:21])=[O:18])[CH:15]=[CH:16][C:4]=2[NH:3]1Dissolve 1 gm of the acid of Example 22 with heating in 100 ml of tetrahydrofuran. Filter and cool the filtrate to room temperature. Add 500 mg. of diazomethane and stir at room temperature for 30 minutes. Strip to dryness and triturate the residue in methanol. Recover the title product by filtration. (m.p. 240°-257° C.).
Wird geladen…