CHROMATOGRAPHY OF METHYL-DERIVATIVES OF 5-ETHYL-5-PHENYL-2-THIOBARBITURIC ACID

Methylation of 5-ethyl-5-phenyl-2-thiobarbituric acid yields two pairs of monomethyl and dimethyl derivatives which are constitutional isome rs differing in the N- vs. S-methyl substitution. These products were separated by column chromatography on silica gel and also by TLC and H PLC. The chiral methyl derivatives and closely related compounds were resolved using beta-cyclodextrin in the mobile phase as a selector. Th e order of the eluted enantiomers was established by chemical transfor mation and correlation with enantiomers of known configuration.