Carbon Dioxide → 3-Isobutoxy-5-methyl-isoxazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 4-iodo-3-isobutoxy-5-methyl-isoxazole (669 mg, 2.38) in THF (10 mL) at −30° C. and under argon was added isopropylmagnesium bromide (1.49 mL of a 2.0 M solution in THF) dropwise. The reaction mixture was warmed to 0° C. and stirred for 1 h, then 1,3,5-trioxane (429 mg, 4.76 mmol) in THF (1 mL) was added and the reaction mixture warmed to 50° C. After 1.5 h to the reaction mixture was added further 1,3,5-trioxane (860 mg, 9.52 mmol) and the reaction mixture heated at 70° C. After 2 h the mixture was cooled to 0° C. and solid CO2 (˜10 g) added. After 1 h the reaction mixture was diluted with water (15 mL) then extracted with diethylether. The aqueous phase was acidified with HCl (1 N, 10 mL), then the resultant precipitate filtered off and washed with water (5 mL), then dried under vacuum (60° C.) to afford the title compound (152 mg, 32%) as a white solid. MS: m/e=198.4 [M−H]−.

Provenance & Evidence