Pyridine → 3-[4-(tert-Butyl-dimethyl-silanyloxy)-3,5-dimethyl-phenyl]-3-hydroxy-1-m-tolyl-1,3-dihydro-indol-2-one

Participants

Reaction Conditions

Reaction Steps

Using a method similar to Preparation 38, with 3-[4-(tert-Butyl-dimethylsilanyloxy)-3,5-dimethyl-phenyl]-3-hydroxy-1,3-dihydro-indol-2-one (11.51 g, 30 mmol), m-tolylboronic acid (8.16 g, 60 mmol), copper (II) acetate (5.45 g, 30 mmol), pyridine (4.9 ml, 60 mmol) and powdered 4A sieves (15 g) in dichloromethane (100 mL) and heat at 32° C. for 1 day stirring mechanically. Add more m-tolylboronic acid (4.08 g, 30 mmol), copper (II) acetate (2.73 g, 15 mmol), pyridine (5.0 ml, 62 mmol) and powdered 4A sieves (15 g) and continue heating for 1 day. Dilute with dichloromethane/ethyl acetate and filter slowly through a pad of Celite and silica gel. Use three such pads to filter the entire reaction washing liberally with ethyl acetate. After the filtration is complete stir the pads in additional ethyl acetate and refilter. Evaporate the organics in vacuo to obtain 17.55 g of a yellow oil. Purify by preparative HPLC (5% ethyl acetate/hexanes for 5 minutes and then use gradient up to 25% ethyl acetate/hexanes) to obtain 9.05 g (64%) of a yellow gum. MS (ES): m/z=474 (M+1); 1H NMR (DMSO-d6); δ7.47 (t, 1H), 7.30-7.23 (m, 5H), 7.09 (t, 1H), 6.77 (d, 1H), 6.72 (s, 1H), 2.39 (s, 3H), 2.14 (s, 6H), 0.99 (s, 9H), 0.17 (s, 6H).

Provenance & Evidence