Synthesis
GENERAL METHODOLOGY: General procedure for the preparation of ethyl 2-((4-chlorophenyl)amino)thiazole-4-carboxylate: a mixture of ethyl 3-bromopyruvate (2.14 g, 11 mmol) and 1-(4-chlorophenyl)thiourea (0.75 g, 10 mmol) was milled in the presence of Na2CO3 (0.50 g) for 5-6 min. The reaction process was monitored by TLC. After completion of the reaction, water (20 ml) was added to the reaction mixture and subsequently extracted with chloroform (20 ml). The separated organic layer was dried with anhydrous sodium sulfate. Excess solvent was removed by distillation. The crude product was filtered and crystallized from aqueous ethanol to give pure solid product in 83% yield. Similarly, other derivatives can be prepared according to the above method and their structures were confirmed by comparison of melting points with literature values.
References
[1] Journal of Medicinal Chemistry, 2015, vol. 58, # 15, p. 5742 - 5750
[2] European Journal of Medicinal Chemistry, 2016, vol. 123, p. 718 - 726
[3] Bioorganic and Medicinal Chemistry Letters, 2013, vol. 23, # 17, p. 4979 - 4984