Figure 1.

(a) Possible mechanism for the synthesis of 2NH₂Ox and 2NH₂Im. The initial formation of α-aminoacetaldehyde is thought to be a potential intermediate on the path to 2NH₂Im, although this exchange reaction may also occur after addition of cyanamide. (b) Partial ¹H NMR spectrum (400 MHz, D₂O) showing the H4/H5 aromatic resonances for 2NH₂Ox (red) and 2NH₂Im (blue) after reaction of glycolaldehyde, cyanamide, sodium phosphate and ammonium chloride, all at 1 M, for 3 h at pH 7 and 60 °C.