Yield:3585-49-7 95.5%

Reaction Conditions:

with water;sodium hydroxide in ethanol at 20; for 3 h;

Steps:

3 Example 3: Preparation of Ibuprofen Impurity B
Add Intermediate 3 compound (1.64 g, 7 mmol, 1.0 eq) to a 100 mL single-necked flaskAnd ethanol (15mL),Add a solution of sodium hydroxide (0.56 g, 14 mmol, 2.0 eq) dissolved in water (2 mL) dropwise with stirring at room temperature,Continue to react for 3 hours after the addition is complete,TLC monitors that the 3 reaction is complete, adjust the pH to 3~4 with 1N HCl.Then extract with EA (20 mL×3),Combine the organic phases and wash with saturated brine,Separate the liquids, dry the organic phase with anhydrous Na2SO4,Concentrate to remove the solvent, and purify by silica gel column chromatography, the elution condition is: dichloromethane: methanol: acetic acid = 50:1: 0.1,Ibuprofen impurity B was 1.38 g, and the yield was 95.5%.

References:

CN112479855, 2021, A Location in patent:Paragraph 0026

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