Potassium Carbonate → Ethyl 2-[4-(hydroxymethyl)phenyl]-1,3-oxazole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a suspension of tris(dibenzylideneacetone)dipalladium (0) (0.025 eq) and tri-tert-butylphosphonium tetrafluoroborate (0.05 eq) a mixture of dioxane and 1N aqueous potassium carbonate (3:1) degassed with nitrogen was added chlorooxazole carboxylate (1 eq) followed by a suspension of 4-hydroxymethylphenylboronic acid (1 eq) in a mixture of dioxane and 1N aqueous potassium carbonate (8:1) continuing to degas with nitrogen and the resulting reaction mixture was stirred at 86° C. (reflux) until determined complete by HPLC (about 2 h). The reaction mixture was allowed to cool to room temperature and filtered through celite, the organic layer separated, and the aqueous layer extracted with ethyl acetate. The dioxane layer was concentrated (avoiding total evaporation to dryness) and combined with the ethyl acetate extract and washed with aq. sodium bicarbonate, brine, dried over sodium sulphate, filtered, evaporated, and triturated with MTBE. The isolated yield of the target compound was 68%. m.p. 99-101° C.; 1H NMR (300 MHz, CDCl3, δ): 8.27 (s, 1H), 8.10 (d, 2H, J=8.2 Hz), 7.47 (d, 2H, J=8.2 Hz), 4.77 (s, 2H), 4.43 (m, 2H, J=7.4 Hz), 1.41 (t, 3H, J=7.4 Hz).

Provenance & Evidence