Asymmetric synthesis of a neuroprotective and orally active N-methyl-D-aspartate receptor ion-channel blocker, CNS 5788

Asymmetric synthesis of N-(2-chloro-5-methylthiophenyl)-N'-(3-methylsulfinylphenyl)-N'-methyl-guanidine (CNS 5788) was achieved in high enantiomeric excess through condensation of the cyanamide derivative, 6 and the sulfinylaniline hydrochloride, 5. The key step involved the asymmetric oxidation of N-methyl-3-methylthioaniline using a Davis reagent. (C) 2000 Elsevier Science Ltd. All rights reserved.