Patent ID: 8158795

Claim:
A process for the preparation of neuromuscular blocking agents with isoquinoline structure by chromatographic purification of their isomeric mixtures characterized by the use of silica modified by treatment with a tertiary amine of formula NR 1 R 2 R 3 or with its corresponding quaternary ammonium compound N + R 1 R 2 R 3 R 4 X − wherein R 1 , R 2 , R 3 and R 4 , the same or different, are linear or branched C 1 -C 4 alkyl groups or —CH 2 —Ar groups or two among R 1 , R 2 , R 3 and R 4 form a 5- or 6-membered cycle, optionally substituted with a —CH 2 —Ar group or condensed with an Ar group, Ar being an aryl optionally substituted with one or more electrodonating groups, and X − being a suitable anion.