[CH2:1]([O:3][C:4]([C:6]1[C:11]2[C:12](=[O:27])[N:13]([CH3:26])[CH2:14][C:15]3[N:16]([CH:17]=[N:18][C:19]=3[C:20]3[N:24]=[C:23]([CH3:25])[O:22][N:21]=3)[C:10]=2[CH:9]=[CH:8][CH:7]=1)=[O:5])[CH3:2].C(O)C[OH:30]>S(=O)(=O)(O)O>[OH:30][CH2:2][CH2:1][O:3][C:4]([C:6]1[C:11]2[C:12](=[O:27])[N:13]([CH3:26])[CH2:14][C:15]3[N:16]([CH:17]=[N:18][C:19]=3[C:20]3[N:24]=[C:23]([CH3:25])[O:22][N:21]=3)[C:10]=2[CH:9]=[CH:8][CH:7]=1)=[O:5]7-Ethoxycarbonyl-5,6-dihydro-5-methyl-3-(5-methyl-1,2,4-oxadiazol-3-yl)-6-oxo-4H-imidazo(1,5-a)(1,4)benzodiazepine (500 mg) was dissolved in ethylene glycol (20 ml) and 3 drops of concentrated sulphuric acid were added. The solution was then stirred at 130° C. for 24 hours, cooled and partitioned between water (150 ml) and CHCl3 (150 ml). The organic phase was separated, dried over Na2SO4, and evaporated to give the title compound as white crystals.
Wird geladen…