An expeditious in situ preparation of benzyl (S)-2-aziridinecarboxylate

The structure-activity relationship of the 3-oxy site in the anticonvulsant (R)-N-benzyl 2-acetamido-3-methoxypropionamide

Lacosamide ((R)-N-benzyl 2-acetamido-3-methoxypropionamide, (R)-1) is a low molecular weight anticonvulsant recently introduced in the United States and Europe for adjuvant treatment of partial-onset seizures in adults. In this study, we define the structure-activity relationship (SAR) for the compound's 3-oxy site. Placement of small nonpolar, nonbulky substituents at the 3-oxy site provided compounds with pronounced seizure protection in the maximal electroshock (MES) seizure test with activities similar to (R)-1. The anticonvulsant activity loss that accompanied introduction of larger moieties at the 3-oxy site in (R)-1 was offset, in part, by including unsaturated groups at this position. Our findings were similar to a recently reported SAR study of the 4'-benzylamide site in (R)-1 ( J. Med. Chem. 2010 , 53 , 1288 - 1305 ). Together, these results indicate that both the 3-oxy and 4'-benzylamide positions in (R)-1 can accommodate nonbulky, hydrophobic groups and still retain pronounced anticonvulsant activities in rodents in the MES seizure model.

Synthesis and anticonvulsant activities of N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide derivatives

Lacosamide has been submitted for regulatory approval in the United States and Europe for the treatment of epilepsy. Previous synthetic methods did not permit the elaboration of the structure-activity relationship (SAR) for the 3-oxy site in lacosamide. We report an expedient five-step stereospecific synthesis for N-benzyl (2R)-2-acetamido-3-oxysubstituted propionamide analogs beginning with D-serine methyl ester. The procedure incorporated alkyl (e.g. methyl, primary, secondary, and tertiary) and aryl groups at this position. The SAR for the 3-oxy site showed maximal activity in animal seizure models for small 3-alkoxy substituents.