Scheme 1
Synthesis of 5,6,7,8-tetrahydro-imidazo [1,2-a]pyrimidine-hydrazone derivatives 8a–k. Reagents and conditions: a 1,1,3-trichloro acetone, NaHCO3, EtOH, reflux, 10 h; b CaCO3, water, reflux, 1 h; c oxone, DMF, 5°C, 2 h; d Conc; H2SO4, ethanol, reflux, 16 h; e 10% Pd–C, Ethanol, H2, 30 psi, 3 h; f hydrazine hydrate, Ethanol, reflux, 6 h; g benzaldehydes a–k, ethanol, reflux, 6 h.