[CH2:1]([N:8]1[CH:16]=[C:15]2[C:10]([CH:11]=[CH:12][C:13]3[C:19](=[O:20])[CH:18]([CH2:21][CH2:22][F:23])[CH2:17][C:14]=32)=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.N12CCCN=C1CCCCC2.[CH:35]([C:37]([CH3:39])=[O:38])=[CH2:36]>C1COCC1>[CH2:1]([N:8]1[CH:16]=[C:15]2[C:10]([CH:11]=[CH:12][C:13]3[C:19](=[O:20])[C:18]([CH2:21][CH2:22][F:23])([CH2:36][CH2:35][C:37](=[O:38])[CH3:39])[CH2:17][C:14]=32)=[N:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1To a solution of 2-benzyl-7-(2-fluoroethyl)-7,8-dihydrocyclopenta[e]indazol-6(2H)-one (11.8 g, 38.3 mmol) in dry THF (100 mL) were added 1,8-diazabicyclo[5.4.0]undec-7-ene (12 mL, 80 mmol) and methyl vinyl ketone (6.4 mL, 77 mmol) and the solution was heated to 55° C. After heating for 72 hours, analysis of an aliquot by 1H NMR showed the reaction to be complete. After cooling to room temperature, the solution was partitioned between 5% MeOH/CH2Cl2 and water and the organic phase was washed with 5% aqueous NaHCO3. The solvent was removed by evaporation under vacuum and the residue was purified by chromatography on silica gel (1:2 to 1:1 EtOAc/hexanes) to give 2-benzyl-7-(2-fluoroethyl)-7-(3-oxobutyl)-7,8-dihydrocyclopenta[e]indazol-6(2H)-one as an orange oil.
読み込み中…