1,3-Dimethoxy-2-propanol → Methyl 7-[2-methoxy-1-(methoxymethyl)ethoxy]-5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-1H-indole-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of methyl 7-hydroxy-5-{[6-(methylsulfonyl)pyridin-3-yl]oxy}-1H-indole-2-carboxylate (1.2 g), tributylphosphine (1.6 mL), 1,1′-(azodicarbonyl)dipiperidine (1.7 g), 1,3-dimethoxypropan-2-ol (0.8 g) and tetrahydrofuran (20 mL) was stirred at 50° C. for 13 h. Tributylphosphine (0.82 mL), 1,1′-(azodicarbonyl)dipiperidine (0.83 g) and 1,3-dimethoxypropan-2-ol (0.4 g) were added to the mixture again and the mixture was stirred at 70° C. for 5 h. Furthermore, tributylphosphine (1.64 mL), 1,1′-(azodicarbonyl)dipiperidine (1.66 g) and 1,3-dimethoxypropan-2-ol (0.8 g) were added to the mixture. After stirring at 70° C. for 3 h, the mixture was cooled to 0° C., and insoluble materials were removed by filtration. The filtrate was concentrated and the residue was purified basic silica gel column chromatography (ethyl acetate/hexane=20/80 to 85/15, volume ratio) to give the title compound (1.79 g, 84%) as an orange oil, MS 463 (MH−).

Provenance & Evidence