Phosgene → 7-(4-Chlorophenyl)-8-isopropyl-3H-chromeno[7,8-d]oxazole-2,6-dione

Participants

Reaction Steps

A stirred solution of 7-amino-3-(4-chlorophenyl)-8-hydroxy-2-isopropyl-chromen-4-one (0.0532 g, 0.16 mmol) in anhydrous methylene chloride (2 ml) is treated at room temperature with a 20% phosgene in toluene solution (0.08 ml). After 30 min, triethylamine (0.032 g, 0.045 ml, 0.32 mmol, 2 eq.) is added, and the reaction mixture is stirred at room temperature for 1 h, transferred to the head of an aminoalkylated silica gel column (Sepra NH2, 50 micrometer, Phenomenex) and purified by flash chromatography (cyclohexane/ethyl acetate=9:1 to 1% acetic acid in ethyl acetate) to afford the title compound.

Provenance & Evidence