Acetic Acid → HCID 90003425, compound

Participants

Reaction Conditions

Reaction Steps

rac-N-((4aR,11bS)-11b-ethyl-10-methyl-1,2,4,4a,5,6,7,11b-octahydrospiro[dibenzo[a,c][7]annulene-3,2′-[1,3]dioxolan]-9-yl)acetamide (25, R2=Ethyl) (0.125 g, 0.350 mmol) in CHCl3 (8 mL) was treated with potassium acetate (0.069 g, 0.699 mmol), AcOH (0.042 g, 0.699 mmol), 18-Crown-6 (15 mg, 0.057 mmol), acetic anhydride (0.071 g, 0.699 mmol) and isopentyl nitrite (0.123 g, 1.049 mmol). The mixture was warmed to about 70° C. for about 3 h then a second portion of isopentyl nitrite (0.200 g, 1.707 mmol) and acetic anhydride (0.110 g, 1.077 mmol) were added. After about 11 h the mixture was cooled to rt and treated with sat. aq. NaHCO3 (3 mL) and water (10 mL). The mixture was extracted with DCM (30 mL) then the organic layer was dried over MgSO4, filtered and concentrated under reduced pressure. The residue was purified on silica gel (12 g) using a gradient of 0-20% EtOAc in DCM. Product fractions were combined and concentrated under reduced pressure to yield rac-1-((4aR,12bS)-12b-ethyl-4a,5,6,7-tetrahydro-1H-spiro[benzo[6,7]cyclohepta[1,2-f]indazole-3,2′-[1,3]dioxolan]-9(2H,4H,12bH)-yl)ethanone (26, R2=Ethyl) (0.083 g, 64%); LC/MS, method 3, Rt=2.87 min, MS m/z 369 (M+H)+. 1H NMR (400 MHz, DMSO) δ 8.37 (d, J=0.6 Hz, 1H), 8.06 (s, 1H), 7.75 (s, 1H), 3.95-3.68 (m, 4H), 3.11-3.04 (m, 1H), 2.98-2.92 (m, 1H), 2.69 (s, 3H), 2.57-2.48 (m, 1H), 2.32-1.13 (m, 12H), 0.59 (t, J=7.4 Hz, 3H).

Provenance & Evidence