Kern J R, Lokensgard D M, Yang T Y
Analytical and Environmental Research, Syntex Research, Palo Alto, CA 94304.
J Chromatogr. 1988 Dec 21;457:309-16. doi: 10.1016/s0021-9673(01)82078-1.
The diastereomeric components of the calcium channel antagonist RS-93522-004 are separated as the bis-3,5-dinitrobenzoate ester by reversed-phase high-performance liquid chromatography. The diastereomer ratio determination is shown to be precise, accurate and sensitive, and is not affected by the reaction yield of the derivatization with 3,5-dinitrobenzoyl chloride. The four individual stereoisomers of RS-93522-004 were independently shown to have equal reactivity toward 3,5-dinitrobenzoyl chloride.
