PCT No. PCT/US98/01413 Sec. 371 Date Sep. 29, 1999 Sec. 102(e) Date Sep. 29, 1999 PCT Filed Jan. 27, 1998 PCT Pub. No. WO98/32759 PCT Pub. Date Jul. 30, 1998Racemic (+/-)-1-azobicyclo[2.2.1]heptan-3-one may be efficiently resolved into its (1S,4R)- and (1R,4S)-1-azabicyclo[2.2.1]heptan-3-one isomers by formation of di-p-toluoyl hemitartrate salts by combination with di-p-toluoyl-L-tartaric acid and di-p-toluoyl-D-tartaric acid, respectively. Selective crystallization using one of the di-p-toluoyltartaric acids in less than stoichiometric amount in a suitable solvent mixture allows isolation of the desired isomer as its respective di-p-toluoyl hemitartrate in high isomeric purity. The isolated hemitartrates are storage stable and may be used as such in the preparation of pharmaceuticals and other biologically active compounds, or may be used to provide the free base of the respective 1-azabicyclo[2.2.1]heptan-3-one isomer.
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