Ba. Kowalczyk et Nh. Dyson, HYDROGENATION OF A CHIRAL 1H-BENZ[DE]ISOQUINOLIN-1-ONE AND AN EQUILIBRATION USING PALLADIUM CATALYST, Organic process research & development, 1(2), 1997, pp. 117-120
The catalytic hydrogenation of a chiral 1H-benz[de]isoquinolin-1-one t
o palonosetron and the undesired diastereomer was optimized using a va
riety of conditions and catalysts, The most selective catalyst for the
production of palonosetron was an unreduced palladium on carbon catal
yst. The(+)- and (-)-camphorsulfonic acid salts of the 1H-benz[de]isoq
uinolin-1-one and the complex of the 1H-benz[de]isoquinolin-1-one with
Mg2+ upon catalytic hydrogenation gave the greatest preference for th
e undesired diastereomer, An equilibration of the undesired diastereom
er from hydrogenation and palonosetron as hydrochloride salts using hy
drogen-activated palladium on carbon catalyst under a nitrogen atmosph
ere was developed, The procedure was used to recycle the hydrochloride
salt of the undesired diastereomer from hydrogenation into pure palon
osetron hydrochloride.