Propargyl alcohol → 5-Chloro-2-(2-chlorophenyl)-7-(3-hydroxy-1-propynyl)-benzoxazole

Participants

Reaction Steps

A solution of 17.15 g (50 mmol) of 7-bromo-5-chloro-2-(2-chlorophenyl)-benzoxazole and 4.40 ml (75 mmol) of propargylalcohol in 32 ml of toluene and 64 ml of triethylamine was heated under nitrogen to 80-5° C. with 175.4 mg (250 μM) of bis(triphenylphosphine)palladium (II) chloride and 8.6 mg (4.5 μM) of copper (1) iodide. After 6 hours, the solid was filtered off and washed with dichloromethane. The solution was evaporated in vacuo. The residue was dissolved in ethyl acetate, washed with 1 N HCl, sodium bicarbonate solution, and water. The ethyl acetate was removed in vacuo, the residue (15.46 g) was dissolved in dichloromethane and filtered through 60 g of silica gel to give the title compound (13.64 g, 85.8%), mp 165-9° C.

Provenance & Evidence