3-ethylisoxazole-5-carboxylic acid synthesis

Yield:14633-21-7 59.9%

Reaction Conditions:

with ethanol;sodium hydroxide at 30; for 1 h;

Steps:

265 EXAMPLE 265: Compound 521B: 3-ethyl-N-{[3-(4-{[(3S,4R)-3-fluoro-1-methylpiperidin-4- yl]amino}-1-(2,2,2-trifluoroethyl)-1H-indol-2-yl)-1,2,4-oxadiazol-5-yl]methyl}-1,2-oxazole-5- carboxamide

To ethyl 3-ethylisoxazole-5-carboxylate (80 mg, 473 μmol, 1 eq) in ethanol (1 mL) was added sodium hydroxide (3 M, 1 mL, 1 eq). The mixture was stirred at 30 °C for 1 h. The reaction mixture was quenched by adding 1N HCl to pH=7 at 0 °C, then concentrated in vacuo to give the carboxylic acid product (200 mg, 59.9% yield) as a yellow solid. LC-MS (ES+, m:z): 139.9 [(M+H)⁺].

References:

WO2021/231474,2021,A1 Location in patent:Paragraph 01126