Nitrogen → 6'-Bromo-4-(difluoromethyl)spiro[cyclohexane-1,2'-inden]-1'(3'H)-one

Participants

Reaction Conditions

Reaction Steps

Methyl 1-(4-bromo-2-iodobenzyl)-4-(difluoromethyl)cyclohexanecarboxylate (Intermediate 90, 2.3 g, 4.72 mmol) was dissolved in THF (30 mL). The atmosphere was exchanged to N2 (g), and the solution was cooled to −20° C. Isopropylmagnesium chloride—lithium chloride (1.3M in THF, 4.00 mL, 5.19 mmol) was added dropwise over one h. The reaction mixture was stirred at −20° C. for 40 min. The reaction mixture was removed from the cooling bath, and left to warm up to r.t., while stirred for 1.5 h. The reaction was stirred at r.t. overnight and then heated at 40° C. for 3 h. The reaction was cooled to r.t. and quenched with sat. NH4Cl. The resulting mixture was stirred overnight. The organic layer was collected and dried over MgSO4, filtered, and concentrated. The residue was purified by flash chromatography (0-10% EtOAc in heptane) followed by preparative chromatography to give the title compound (0.562 g, 24% yield): 1H NMR (500 MHz, DMSO-d6) δ ppm 1.46-1.65 (m, 4 H), 1.75-1.96 (m, 5 H), 2.93 (s, 2 H), 6.00 (dt, 1 H), 7.51 (d, 1 H), 7.73 (d, 1 H), 7.83 (dd, 1 H).

Provenance & Evidence