Dichloromethane → HCID 16037701, compound

Participants

Reaction Steps

In a flame-dried flask filled with argon, the silyl ether 8-[dimethyl-1,1,2-trimethyl-propyl)-silanyloxy]-7-[(3R)-3-hydroxy-3-phenyl-propyl]-2,3-dimethyl-imidazo[1,2-a]pyridine-6-carboxylic acid dimethylamide (2.10 g, 4.1 mmol, sample contained 6 mol-% of the (3S)-enantiomer) was dissolved in dry THF (30 ml). At room temperature, a solution of tetrabutylammonium fluoride in THF (1 M, 420 ml, 4.2 mmol) was added slowly. A brown solution was obtained, which was stirred for 5 hours at room temperature. The reaction mixture was poured onto a mixture of saturated ammonium chloride solution (30 ml) and dichloromethane (50 ml). The phases were separated and the aqueous phase was extracted with dichloromethane (3×15 ml). The combined organic phases were washed with water (20 ml), dried over sodium sulfate, and concentrated under reduced pressure. A grey solid (2.6 g) remained which was treated with a mixture of acetone (I ml) and diethyl ether (10 ml). The suspension was filtered, the residue was washed with diethyl ether and dried in vacuo. This afforded 1.6 g of the title compound still containing traces of impurities. After crystallization from ethyl acetate (100 ml) and isopropanol (10 ml), the spectroscopically pure title compound (1.3 g, 86% yield) was obtained as a grey crystalline solid. The optical purity was confirmed by capillary electrophoresis (85.2% ee).

Provenance & Evidence