Yields and physical properties of imidazo[1,2-a]pyridine-N-glycinyl-hydrazone derivatives 1a–k.

aThe analytical results for C, H and N were within 0.4% of the calculated values for all N-acylhydrazone derivatives 1a–k. The purity of N-acylhydrazone derivatives 1a–k was also determined by reversed-phase HPLC.bThe yields refer to the condensation step of hydrazides 8a–b with the corresponding aromatic aldehydes (see Figure 2).cObtained as a yellow oil (see Material and Methods).