p-Toluenesulfonic acid → HCID 66876645, compound

Participants

Reaction Steps

A solution of 8.526 mmol of (3R,4R,5S)-4-[4-((S)-3-methoxy-2-methyl-propoxymethyl) -phenyl]-3-[4-(3-methoxy-propyl)-3-oxo-3,4-dihydro-2H-benzo [1,4]oxazin-6-ylmethoxy]-5-trityloxymethyl-piperidine-1-carboxylic acid benzyl ester in 20 ml of tetrahydrofuran and 80 ml of methanol is treated with 12.789 mmol of toluene-4-sulfonic acid.monohydrate. After stirring for 15 hours, the reaction mixture is basified with saturated aqueous sodium bicarbonate solution and concentrated under reduced pressure to remove most of the methanol and tetrahydrofuran. The residue is extracted with dichloromethane (3×)—the combined organic layers are washed successively with water and brine, dried with sodium sulfate and evaporated. The title compound is obtained as a yellow oil from the residue by flash chromatography (SiO2 60F). Rt=4.86 (gradient I).

Provenance & Evidence