Abstract A series of 1-acylated and 1, 3-diacylated (acyl= acetyl or benzoyl) ureas and thioureas have been prepared and their proton-coupled and proton-decoupled 15 N, 13 C, and 1 H NMR spectra have been measured. All the signals have been assigned. The 15 N NMR chemical shifts in 1-acylated ureas and thioureas are shifted downfield as compared with δ (15 N) of urea and thiourea, resp. This shift is greater for N-1 than for N-3 nitrogen ...
