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. The reaction mixture was then cooled to RT, and extracted with EtOAc (2×100 mL). The extracts were washed sequentially with water and brine, then dried (MgSO4), filtered and conventrated in-vacuo to afforded 13.3 g of crude product. This material 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, 4H) 1.77-2.01 (m, 6H) 2.80 (d, J=11.83 Hz, 1H) 3.02-3.18 (m, 1H) 3.89 (s, 3H) 6.49 (d, J=11.33 Hz, 1H) 7.34 (t, J=7.55 Hz, 1H) 7.46 (t, J=7.55 Hz, 1H) 7.62 (d, J=7.30 Hz, 1H) 7.66-7.74 (m, 2H) 7.77 (d, J=7.81 Hz, 1H) 8.21 (s, 1H).

Provenance & Evidence