Efficient One-Pot Synthesis of Thiazol-2-imine Derivatives through Regioselective Reaction Between Primary Amines, Phenylisothiocyanate, and α-Chloroacetaldehyde

Title:Efficient One-Pot Synthesis of Thiazol-2-imine Derivatives through Regioselective Reaction Between Primary Amines, Phenylisothiocyanate, and α-Chloroacetaldehyde

Volume: 20 Issue: 1

Author(s): Farough Nasiri and Leila Sabahi-Agabager

Affiliation:

Keywords: α-Chloroacetaldehyde, thiazol-2-imine, 1, 3-disubstituted thiourea, one-pot reaction.

Abstract: 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, CH₃CN, THF, CH₂Cl₂, and H₂O 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 excellent.

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.

Cite this article as:

Nasiri Farough and Sabahi-Agabager Leila, Efficient One-Pot Synthesis of Thiazol-2-imine Derivatives through Regioselective Reaction Between Primary Amines, Phenylisothiocyanate, and α-Chloroacetaldehyde, Combinatorial Chemistry & High Throughput Screening 2017; 20 (1) . https://dx.doi.org/10.2174/1568009617666161107093942

DOI https://dx.doi.org/10.2174/1568009617666161107093942	Print ISSN 1386-2073
Publisher Name Bentham Science Publisher	Online ISSN 1875-5402