... via NMR Tomihiro Nishiyama, Yoshiaki Iwasaki, Takeshi Nishikawa, Shinji Miyatake and Fukiko Yamada* Department of Applied Chemistry, Faculty of ... 1369 J. Heterocyclic Chem., 28, 1369 (1991). ... 80 -С 1b 1 1 1— 5 4 6 3 Figure 1. The pmr spectra of the heterocyclic protons of ...