Acetic Acid → 3-acetyl-7,8-dihydrocyclopenta[e]indazol-6(3H)-one

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of N-(4-methyl-1-oxo-2,3-dihydro-1H-inden-5-yl)acetamide (20.00 g, 98.40 mmol), potassium acetate (19.32 g, 197 mmol), acetic acid (11.3 mL, 197 mmol), acetic anhydride (18.6 mL, 197 mmol) and 1,4,7,10,13,16-hexaoxacyclooctadecane (5.20 g, 19.7 mmol) in 600 mL of chloroform was heated at 65° C. and isopentyl nitrite (33.0 mL, 246 mmol) was added during 10 minutes. The mixture was stirred at 65° C. for 23 hours and was then allowed to cool to room temperature. The reaction mixture was diluted with chloroform and washed successively with saturated NaHCO3 (2×), water and brine. After drying over Na2SO4, the solution was concentrated to low volume under vacuum and flash chromatographed on silica gel eluting with EtOAc/dichloroethane (0:100 to 10:90) to give 3-acetyl-7,8-dihydrocyclopenta[e]indazol-6(3H)-one as a yellow solid.

Provenance & Evidence