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.
用碘甲烷将 t-丁基取代的嘧啶-4-醇中的阴离子甲基化。通过质子耦合 13C n.m.r.确定了甲基化的位点,并通过 1H n.m.r.确定了异构体的相对比例。环氮正交的叔丁基取代基明显降低了该氮的甲基化倾向,以至于观察到在这些条件下不常见的 O-甲基化。