... The proton magnetic resonance ('H (C) 1989 Pharmaceutical Society of Japan NIT—Electronic Library Service ... A o 0 R1 c=NR' CHNHRZ 4k r—“—> NHR2 0 N NH <-—— 2 Chart 4 Vol. ... Chemical shifts are quot— ed in parts per million (s=singlet, d=doublet, t=triplet, m=mu1tiplet ...