The solid-state thermal reactions of 2,6-diamino-4-chloropyrimidine, 3,3-dimethoxybenzidine and of thiosemicarbazide with
each of 2-hydroxy-1-naphthaldehyde and 2,4-dihydroxybenzaldehyde in a mole ratio of 1∶1 produced (1+1) condensation products
(‘half units’). These solid state reactions have been studied by means of differential thermal analysis (DTA). The products
of the reactions were identified using elemental analysis and IR spectroscopy. Some kinetic parameters such as orders and
activation energies of the reactions were evaluated form the DTA curves.