Water → HCID 14461332, compound

Participants

Reaction Steps

A solution of 30 g (76.5 mmol) of the compound of example 5 in 200 ml of warm tetrahydrofuran is added dropwise to 19.1 ml (0.19 mol) of a 1N solution of borane acid in tetrahydrofuran at 0° C. under an argon atmosphere; 0.5 g (13.2 mmol) of sodium hydridoborate are then added and the mixture is stirred for 2 h at room temperature. Then 180 ml of cold water are added dropwise with care and the mixture is boiled for 1 h under reflux. The mixture is adjusted to a pH of 13 with 10 ml of 6N sodium hydroxide solution, extracted three times, each time with 200 ml of ethyl acetate and the combined organic phases are dried over sodium sulphate and evaporated to dryness. The residue is chromatographed on 500 g of silica gel (230 to 400 mesh) with dichloromethane, dichloromethane/methanol (10:1) and dichloromethane/methanol/concentrated ammonia (100:10:1) until the main product emerges with the lowest Rf -value.

Provenance & Evidence