Isoamyl Nitrite → Ethyl 5-chloro-1,3-thiazole-4-carboxylate

Participants

Reaction Steps

21 g (123 mmol) ethyl 2-aminothiazol-4-carboxylate (Example 30, step 1) was added to 150 ml acetonitrile, and 18.4 g (137 mmol) NCS was added portionwise, to carry out reaction at room temperature overnight; and then, 19 ml (137 mmol) isoamyl nitrite was added rapidly dropwise, followed by continuing the reaction for 2 hr after complete of addition. The resultant reaction mixture was concentrated, then ethyl acetate and water were added, and filtered to remove insoluble solids. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated to obtain 20 g ethyl 5-chlorothiazol-4-carboxylate 1H NMR (CDCl3) 1.42-1.45 (3H, t, J=7.0 Hz); 4.43-4.46 (2H, m, J=7.0 Hz); 8.68 (1H, s); MS (EI) 191.0 (M+).

Provenance & Evidence