Phosphorus pentachloride → Methyl 2-chlorobenzo[d]oxazole-4-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of the thione from Step B (0.65 g, 3.11 mmol) and phosphorus pentachloride (0.65 g, 3.11 mmol) in phosphorus oxychloride (6 mL) was heated to 95° C. for 2.5 h. After cooling to room temperature, the reaction mixture was concentrated and dried on vacuum to give methyl 2-chlorobenzoxazole-4-carboxylate (0.66 g, quantitative) as a brown solid: 1H NMR (300 MHz, CDCl3) δ 8.05 (dd, J 8.1, 1.2 Hz, 1H), 7.72 (dd, J 8.1, 1.2 Hz, 1H), 7.45 (t, J=8.1 Hz, 1H), 4.04 (s, 3H); MS (ESI+) m/z 212 (M+H).

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