[C:1]([C:3]1[CH:7]=[C:6]([CH2:8][CH3:9])[NH:5][C:4]=1[C:10]([OH:12])=[O:11])#[N:2].[CH3:13][Si](C=[N+]=[N-])(C)C.CCOCC>C1COCC1>[CH3:13][O:11][C:10]([C:4]1[NH:5][C:6]([CH2:8][CH3:9])=[CH:7][C:3]=1[C:1]#[N:2])=[O:12]3-Cyano-5-ethyl-1H-pyrrole-2-carboxylic acid (Intermediate 31) (500 mg) was dissolved in anhydrous THF (5 ml) and cooled to 0° C. (Trimethylsilyl)diazomethane/ether (2 ml) was added. The mixture was stirred at room temperature under nitrogen gas for 1 h. The solvent was removed in vacuo and MeOH was added. The mixture was stirred for a further 15 min, the solvent was removed in vacuo and the solid was dried under vacuum to give the title compound (580 mg).
Wird geladen…