HCID 20243492, compound → HCID 13619047, compound

Participants

Reaction Steps

A 1-l flask connected to a hydrogenation apparatus and placed on on air driven magnetic stirrer is charged with 4-(2-benzyloxyethyl)-3-ethyl-azetidin-2-one (19.5 g), glacial acetic acid (200 ml) trifluoroacetic acid (9.47 ml) and 10% Palladium on carbon (2.9 g). The mixture is hydrogenated at room temperature and pressure for about 3 hours, then the catalyst is removed by filtration under vacuum, washing with acetic acid. The solvent is evaporated under reduced pressure by heating to 40°-50° C. and the obtained residue is dissolved in methanol (150 ml). Anhydrous potassium carbonate (17.27 g) is added to the resulting solution and the obtained mixture is stirred for 30 minutes. The inorganic salts are removed by filtration and the filtrate is brought to pH 6 by the addition of dilute acetic acid. The residue which is obtained by evaporating the solvent is taken up with water (100 ml) and extracted with toluene (three 50-ml portions). The toluene extracts are washed with a small amount of water and then discarded while the mother liquors plus the aqueous washes are combined, saturated with (NH4)2SO4 (100 g) and extracted with ethyl acetate (five 50-ml portions). The organic extracts are dried over Na2SO4 and evaporated to dryness under vacuum yielding 9.7 g of 3-ethyl-4-(2-hydroxyethyl)-azetidin-2-one as a 6:4 cis/trans mixture.

Provenance & Evidence