Richter Gedeon Vegyeszeti Gyar Rt

Chinoin Gyogyszer Es Vegyeszeti Termekek Gyara Rt.

Alkaloida Vegyeszeti Gyar

Elemer Fogassy

Laszlo Toke

Ferenc Faigl

Kalman Harsanyi

Rudolf Soos

Tibor Gizur

Jozsef Nemes

Rezso Kolta

Zsuzsanna Aracs Nee Tischler

Zsuzsanna Martonffy Nee Jaszay

Katalin Berki

Maria Cs

Jozsef Bozzay

Peter Bencsik

Maria Acs

Process for the resolution of

Diastereomer salts of phenylalanine and N-acyl derivatives thereof and

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

Growing community of inventors

Budapest, Hungary

Elemer Fogassy