Tetrahydrofuran → methyl 1-{1-[2-(7-methoxy-2,2-dimethyl-4-oxochroman-8-yl)ethyl]piperidin-4-yl}-1H-indole-6-carboxylate

Participants

Reaction Steps

28 mL of DME, 14 mL of tetrahydrofuran and 1.24 mL of acetic acid were added to 2.80 g of methyl 1-piperidin-4-yl-1H-indole-6-carboxylate and 3.16 g of (7-methoxy-2,2-dimethyl-4-oxochroman-8-yl)acetaldehyde. Although crystals precipitated, the reaction mixture was stirred for one hour as it was. The reaction mixture was cooled with an ice-water bath, and 2.75 g of sodium triacetoxyborohydride was added portionwise divided into three to the reaction mixture. The reaction mixture was warmed to room temperature and added with 3 mL of tetrahydrofuran and about 1.5 hours later, progress of the reaction was confirmed. The reaction mixture cooled with an ice-water bath again and added with 68 mL of toluene and 29 mL of water and, after clarification and filtration, added with 30 mL of toluene and the aqueous layer was discarded. The organic layer was washed with 29 mL of 1 N aqueous sodium hydroxide, 29 mL×2 of 5% sodium chloride solution and 29 mL of water. The solvent was evaporated and 5.62 g of the crude title compound was obtained.

Provenance & Evidence