15 N NMR spectra of pyrimidine and [1,3‐ 15 N 2 ]pyrimidine

The fully proton‐coupled 15 N NMR spectra of pyrimidine with natural isotope abundance and of bis‐labelled [1,3‐ 15 N 2 ]pyrimidine, obtained using single pulse experiments, are described. The 15 N and 1 H spectra are analysed for 2 J , 3 J and 4 J (NH) as well as N,N and H,H coupling constants.