Hydrochloric Acid → (spiro[cyclopentane-1,3'-[3H]indol]-2'(1'H)-one-5-yl)boronic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-bromo-spiro[cyclopentane-1,3′-[3H]indol]-2′(1′H)-one (13.1 g, 53 mmol) in anhydrous THF (300 cm3) under N2, was added sodium hydride (60% in mineral oil, 2.1 g, 53 mmol). After 30 minutes, the reaction mixture was cooled to −78° C. and butyl lithium (2.5 M in hexanes, 22 cm3, 53 mmol) was added slowly. After 30 minutes, tris-iso-propylborate (34 cm3, 146 mmol) was added, and the reaction mixture was slowly brought to room temperature, and stirred for 14 hours. The reaction mixture was poured into 1N HCl and extracted with EtOAc (×3). The organic layers were collected and washed with 1N HCl, water, dried (MgSO4) and evaporated to give the subtitled compound (7.8 g, 64%) as a tan solid which was used without further purification. 1H NMR (DMSO-d6) δ 10.3 (s, 1H), 7.9 (s, 1H), 7.7–7.6 (m, 2H), 6.8 (d, 1H, J=7.7 Hz), 3.4 (s, 1H), 2.0–1.7 (m, 8H); MS (FI-POS) m/z @231.

Provenance & Evidence