Ethyl 5-formylisoxazole-3-carboxylate synthesis

Yield:22667-24-9 80%

Reaction Conditions:

with 2-iodoxybenzoic acid in ethyl acetate at 90; for 17 h;

Steps:

22.2; 34.2; 69.2; 135.2 Step 2:

Step 2:
Preparation of ethyl 5-formylisoxazole-3-carboxylate
To a solution of ethyl 5-(hydroxymethyl)isoxazole-3-carboxylate (4.5 g, 26.3 mmol) in ethyl acetate (80.0 mL) was added 2-iodoxybenzoic acid (22.1 g, 78.9 mmol).
After addition, the reaction mixture was heated to 90° C. and stirred for 17 h, then cooled to room temperature.
The reaction mixture was filtered and concentrated in vacuo.
The residue was purified by column chromatography (silica, petroleum ether/ethyl acetate=6/1) to give ethyl 5-formylisoxazole-3-carboxylate (3.5 g, 20.7 mmol, 80%) as a yellow oil.

References:

US2019/330198,2019,A1 Location in patent:Paragraph 0680; 0782; 1070; 1377