Hydrochloric Acid → HCID 67312850, compound

Participants

Reaction Steps

To a solution of methyl 3-({2-[(cyclopropylcarbonyl)amino]-1,3-benzooxazol-6-yl}oxy)benzoate (8.2 g) in methanol (300 mL) was added 8N aqueous sodium hydroxide solution (50 ml), and the mixture was stirred at room temperature for 2 days. To the reaction mixture was added 6N hydrochloric acid to adjust the pH to about 6.0, and the reaction mixture was concentrated under reduced pressure to about 100 mL. Ethyl acetate (200 mL) was added to the residue, and the mixture was washed with water (150 mL×2). The collected aqueous layer was extracted with ethyl acetate (100 mL×2), and the combined organic layers were dried over anhydrous magnesium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure to give a brown amorphous substance. The obtained crude product was dissolved in toluene (150 mL) and 2-methylpropan-2-ol (100 mL), and the solvent was evaporated under reduced pressure. An azeotropic operation with toluene and 2-methylpropan-2-ol was further repeated twice to remove water from the crude product. The obtained brown amorphous substance (8.6 g) was used as the title compound in the next operation without a further purification.

Provenance & Evidence