Water → Methyl 2-chlorodibenzo[b,f]oxepin-11-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 415.23 g (2.33 mol) of pyrophosphoric acid and 22.14 g of water at 0° C. was added over methyl 2-(5-chloro-2-phenoxyphenyl)-3-hydroxyacrylate (compound IXa) as obtained in Example 16. The reaction mixture was stirred at 60° C. for 2 hours. After cooling to 20° C., 500 mL of water and 1.4 L of methyl tert-butyl ether were added. The aqueous layer was extracted and washed with 200 mL of methyl tert-butyl ether. The organic phases were combined, washed with 400 mL of an aqueous saturated solution of sodium bicarbonate and 400 mL of saturated sodium chloride, dried over anhydrous sodium sulfate and concentrated to dryness under reduced pressure. The residue was suspended in 400 mL of n-butanol and stirred at room temperature for 1 hour, and at 0° C. for 2 hours. The resulting suspension was filtered, and the solid was dried until constant weight to obtain 161 g of methyl 2-chlorodibenzo[b,f]oxepin-11-carboxylate (compound Xa) as an off-white solid. Yield: 77.7%.

Provenance & Evidence