Methylation of Some Deprotonated Sterically Hindered Pyrimidin-4-ols

Abstract

Anions derived from t-butyl-substituted pyrimidin-4-ols were methylated with iodomethane . The site of methylation was determined by proton-coupled ¹³C n.m.r. and the relative proportions of isomers were determined by ¹H n.m.r. A t-butyl substituent ortho to a ring nitrogen markedly reduced the propensity for methylation at that nitrogen to the point where O-methylation, uncommon under these conditions, was observed.