2-Formylphenylboronic acid → methyl 11-cyclohexyl-6-hydroxy-6H-isoindolo[2,1-a]indole-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of methyl 2-bromo-3-cyclohexyl-1H-indole-6-carboxylate (10.1 g, 30 mmol), 2-formylphenylboronic acid (5.4 g, 36 mmol), LiCl (3.8 g (90 mmol) and Pd (PPh3)4 (1.6 g, 1.38 mmol) in 1M Na2CO3 (40 mL) and 1:1 EtOH-toluene (180 mL) was heated under nitrogen at 85° C. for 3 hours. Reaction mixture was allowed to cool and then extracted with EtOAc (2×100 mL), washed with water, brine and then dried (MgSO4). Evaporation of solvents afforded 13.3 g of crude product which was triturated with DCM and hexanes to provide pure desired product (7.52 g, 70%). LC-MS: m/e 360 (M−H)−; 344 (M−17)+. 1H NMR (400 MHz, CHLOROFORM-D) δ ppm 1.33–1.60 (m, 4 H) 1.77–2.01 (m, 6 H) 2.80 (d, J=11.83 Hz, 1 H) 3.02–3.18 (m, 1 H) 3.89 (s, 3 H) 6.49 (d, J=11.33 Hz, 1 H) 7.34 (t, J=7.55 Hz, 1 H) 7.46 (t, J=7.55 Hz, 1 H) 7.62 (d, J=7.30 Hz, 1 H) 7.66–7.74 (m, 2 H) 7.77 (d, J=7.81 Hz, 1 H) 8.21 (s, 1 H).

Provenance & Evidence