Chinoin Gyogyszer Es Vegyeszeti Termekek Gyara Rt.

Peter Bencsik

Rudolf Soos

Laszlo Toke

Jozsef Nemes

Ferenc Faigl

Elemer Fogassy

Rezso Kolta

Jozsef Bozzay

The invention relates to a process for the preparation of enantiomers of trans vinyl-cyclopropane carboxylic acids of the formula I, ##STR1## wherein R is a methyl group or chlorine atom, by resolution of racemic trans compound or mixture of racemic cis and trans compounds by using (+)- or (-)-N-(1-formamido-2,2,2-trichloroethyl)-piperazine as a resolving agent in a polar solvent then separating the crystallizing salt of (+)-trans carboxylic acid and (-)-resolving agent or (-)-trans carboxylic acid and (+)-resolving agent from the mother liquor by filtration and obtaining the enantiomers by acidifying the mother liquor or the salts suspended in water followed by extraction with a solvent and evaporation. The products so obtained may be used as starting materials for the preparation of insecticides.

Process for the preparation of optically active cyclopropane carboxylic

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Budapest, Hungary

Peter Bencsik