Formic Acid → (1S,2R)-2-amino-1-phenylpropan-1-ol

To remove the benzyl group, 3.9 mmol of (1R,2S)-1-phenyl-2-(N,N-dibenzylamino)-1-propanol are dissolved in 5 ml of methanol. This solution is added to a mixture of 40 ml of methanol, 10.6 g of formic acid and 50 mg of palladium black. The air is displaced from the reaction vessel using hydrogen. After hydrogenation for 1 hour, the palladium catalyst is filtered off, and the solution is concentrated in vacuo. The residue is taken up in 10 ml of methanol and stirred with 1 g of silica gel and 5 drops of concentrated hydrochloric acid at room temperature for 1 hour. The residue obtained after removal of the silica gel by filtration and concentration of the filtrate is purified by chromatography. 243 mg (=60% of theory) of analytically pure norephedrine are obtained.

1. filtrationthe palladium catalyst is filtered off
2. concentrationthe solution is concentrated in vacuo
3. customThe residue obtained
4. customafter removal of the silica gel
5. filtrationby filtration and concentration of the filtrate
6. customis purified by chromatography

ORD-Eintrag

ord-4dffb0f709fb45c9ae0eaf63e77339f3

Quelldatensatz

uspto-grants-1991_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04990669