4335-77-7

31197-69-0

4335-77-7

General procedure for the synthesis of 2-cyclohexyl-2-hydroxyphenylacetic acid from oxybutynin impurity 2: To a solution of methanol (20 mL) containing cyclohexyl-hydroxy-phenylacetic acid (1.04 g, 3.96 mmol) was added a 1N NaOH solution (8 mL). The reaction mixture was heated to 80 °C and stirred continuously for 3.5 hours. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently extracted with ether. The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate and finally concentrated under reduced pressure to give the crude product as a white solid. Purification of the crude product by recrystallization from a solvent mixture of hexane and dichloromethane afforded 900 mg of 2-cyclohexyl-2-hydroxyphenylacetic acid in 97% yield. The structure of the product was confirmed by 1H-NMR (CDCl3).