Trifluoroacetic acid → HCID 14732723, compound

Participants

Reaction Steps

Trifluoroacetic acid (18 ml) was added to a solution of the product of Stage (a) (2.4 g) in anisole (18 ml) at 0°. The mixture was stirred at room temperature for 2 hours and concentrated. The residue was dissolved in ethyl acetate and extracted with saturated sodium bicarbonate solution. The pH of the aqueous extracts was adjusted to 6, and the solution washed with ethyl acetate. The aqueous phase was acidified to pH 1.5 under ethyl acetate, saturated with sodium chloride, and extracted with ethyl acetate. The combined organic extracts were washed with saturated brine, dried and evaporated. The residue was dissolved in warm 50% aqueous formic acid (20 ml) and allowed to stand for 2 hours. The mixture was diluted with water (50 ml). and filtered. The filtrate was concentrated. The residue was taken up in water (50 ml), refiltered, and lyophilized to give the title compound (920 mg), λmax (pH 6 buffer) 236 nm (E1 cm1% 250), λinf 255 nm (E1 cm1% 235), 296 nm (E1 cm1% 103); [α]D20 +20.0° (c 1.0, DMSO).

Provenance & Evidence