Triethylamine → Phenyl (4-chloropyridin-2-yl)-N-(phenoxycarbonyl)carbamate

Participants

Reaction Steps

2-Amino-4-chloropyridine (5.00 g, 38.9 mmol, WO 02/32872) was dissolved in tetrahydrofuran (200 ml); and triethylamine (17.9 ml, 128 mmol) was added thereto. While stirring with a waterbath, phenyl chloroformate (14.6 ml, 117 mmol) was added thereto dropwise; the reaction mixture was stirred at room temperature for 1.5 hours. The reaction mixture was partitioned between water and ethyl acetate; the organic layer was washed with brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The obtained residue was filtered by silica gel; the crystals obtained after the concentration were suspended in diethyl ether, filtered off, washed with diethyl ether, and dried to yield the title compound (3.77 g, 10.2 mmol, 26.3%) as pale yellow crystals. The mother liquor was concentrated under reduced pressure, which was then treated by the similar methods to yield the title compound (3.98 g, 10.5 mmol, 27.1%) as pale yellow crystals (secondary crystals).

Provenance & Evidence