Bromine → 5'-Bromo-1',2'-dihydrospiro[cyclohexane-1,3'-indole]-2'-one

Participants

Reaction Steps

To a solution of spiro[cyclohexane-1,3′-[3H]indol]-2′(1′H)-one (17.6 g, 0.09 mol) in acetic acid (300 cm3) was added sodium acetate (8.0 g, 0.1 mol) and bromine (14.6 g, 0.091 mol) with stirring. After 30 min. at room temperature, the reaction mixture was partitioned between water and EtOAc. The aqueous phase was extracted twice with EtOAc. The combined organic layers were washed with water, dried (MgSO4) and evaporated and the residue was triturated with hexane. The precipitate was collected, and dried in vacuo to obtain the title compound (16.5 g, 67%) as off-white crystals: mp 196-199° C.; 1H NMR (DMSO-d6) δ 1.62 (m, 10H), 6.8 (d, 1H, J=6.8 Hz), 7.36 (d, 1H, J=8.2, 1.8 Hz), 7.58 (dd, 1H, J=8.2, 1.8 Hz), 10.44 (s, 1H).

Provenance & Evidence