... The residue was crystallized from ethanoliwater (4:l) to give 1.3 g (84%) of Vb, mp 129-131'. Table I 'H NMR Chemical Shifts (6) and IR Data (cm-') Compound Aromatic Piperazine CH,CH, Others cm-' ... 1131 E. Eichler, CS Rooney and HWR Williams, J. Heterocyclic ...