Aim and Objective: Thiazol-2-imine derivatives are interested for their pharmaceutical and
biologic activities. A literature survey reveals that there have been no any reports on the synthesis of
thiazol-2-imine derivatives without substituents in position C-4 and C-5 via one-pot reaction. Herein
we report an efficient one-pot route for synthesis of these compounds in good to high yields.
Materials and Method: To a stirred mixture of amine (1 mmol) and phenylisothiocyanate (1 mmol) in
EtOH (2 ml), KI (0.1 mmol) and DABCO (0.2 mmol) were added under reflux condition. Then α-
chloroacetaldehyde (2 mmol) was added drop wise to the reaction mixture. After completion of the
reaction, the product was purified over a silica gel short column (EtOAc/n-Hexane, 1:9).
Results: One pot reaction of primary amine, phenylisocyanate, and α-chloroacetaldehyde was carried
out in the presence of various base and KI in different solvents. It was found that the maximum yield
was obtained when the temperature reaches to the boiling point of EtOH. Comparing the reaction
results in EtOH, CH3
CN, THF, CH2
, and H2
O at reflux in the presence of various base, demonstrate
that the yield of reaction in EtOH in the presence of DABCO was the most effective. When the reaction
runs at the 20 mol% of the DABCO and 10 mol% of the KI, the yield and the time of the reaction were
Conclusion: One-pot procedure can be used for the synthesis of thiazol-2-imine derivatives via the
reaction of primary amines, α-chloroacetaldehyde, and phenylisothiocyanate in the presence of a
catalytic amount of DABCO and potassium iodide in ethanol.