H-3 LABELING OF PROKINETIC MOTILIDE ABT-229 FOR BIODISTRIBUTION AND METABOLISM STUDIES

The prokinetic drug candidate, ABT-229, has been successfully [H-3]-la beled in the marolactone ring. This was accomplished with [H-3]-NaBH4 reduction of the 11-ketone analog in a four step synthetic sequence be ginning with the drug candidate. The H-3-labeled drug was obtained wit h specific activity of 9.0 Ci/mmol and radiochemical purity >99%. This constitutes the first methodology for H-3-labeling of the macrolacton e in an erythromycin derivative.