L-, D-, and DL-Ephedrine Phosphates
A. Larizza, G. Brancaccio, A. Segre
J. Med. Chem. 9, 966-967 (1966) (https://www.thevespiary.org/rhodium/Rhodium/pdf/meth.ephedrine.phosphate.pdf)
(https://www.thevespiary.org/rhodium/Rhodium/pdf/meth.ephedrine.phosphate.pdf)
Reaction of L-Ephedrine with POCl3 gave L-2-Chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazophospolidine 2-oxide, which upon hydrolysis yielded L-Ephedrine O-phosphate Hydrochloride. Catalytic hydrogenation of 2.8g of the ester salt using 0.28g 5% Pd-C (2h, 1 atm, 22°C) in 40 mL ethanol gave, after filtration, acid/base extraction and distillation of the freebase (bp 91-93°C/15 mmHg) 1.2 grams of product amine (84% yield).
It's from the reference list at the end of https://www.thevespiary.org/rhodium/Rhodium/chemistry/amphetamine.reduction.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/amphetamine.reduction.html)
I'm trying to link up the entire reference list to the original literature (or the pertinent sections from the referenced article).