Pyridine → 2-Carbomethoxy-5-tert-butyl-3-furyl isocyanate

Participants

Reaction Steps

To a solution of phosgene (1.93M in toluene, 9.7 mL, 18.6 mmol, 3.0 equiv) in CH2Cl2 (80 mL) at 0° C. was added a solution of methyl 3-amino-5-tert-butylfuran-2-carboxylate (1.23 g, 6.2 mmol) and pyridine (1.97 g, 24.9 mmol, 4.0 equiv) in CH2Cl2 (20 mL). The reaction mixture was allowed to slowly warm to room temp. and rapidly form a precipitate. The resulting slurry was stirred at room temp. for 1 h, then concentrated under reduced pressure to give 2-carbomethoxy-5-tert-butyl-3-furyl isocyanate and pyridinium hydrochloride. 2-Carbomethoxy-5-tert-butyl-3-furyl isocyanate: 1H NMR (CDCl3) δ1.25 (s, 9H), 4.85 (s, 3H), 5.90 (s, 1H). The mixture was used in the next step without further purification.

Provenance & Evidence