Lawesson's reagent → Ethyl 5-amino-2-phenyl-1,3-thiazole-4-carboxylate

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Reaction Steps

To a stirred solution of compound ethyl 2-benzamido-2-cyanoacetate (0.46 g, 2 mmol) in pyridine (20 mL) was added Lawesson's reagent (0.81 g, 2 mmol). The reaction mixture was heated at reflux for 15 hr. It was then concentrated and diluted with EtOAc (40 mL). The diluted mixture was washed with water (3×20 mL), brine (10 mL), dried over Na2SO4, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (10:1 PE/EtOAc) to afford ethyl 5-amino-2-phenylthiazole-4-carboxylate (0.2 g, 40%) as yellow solid: 1H-NMR (CDCl3, 500 MHz) δ (ppm): 7.80 (d, J=6.5 Hz, 1H), 7.36-7.41 (m, 3H), 4.43 (q, J=7.0 Hz, 2H), 1.44 (t, J=7.0 Hz, 3H); MS (ESI) m/z: 249 [M+H+].

Provenance & Evidence