| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject compound useful as an intermediate for a cartilage-protection agent in high yield by reacting a specific esculetin derivative with a halogen compound in an organic solvent in the presence of a metal carbonate. SOLUTION: The objective esculetin derivative of the formula II having selectively protected 7-hydroxyl group can be produced by reacting an esculetin derivative of the formula I [R<1> is COOR<2> (R<2> is H, an alkyl or a cycloalkyl), H, OH, an alkyl, a cycloalkyl, an aryl or an aralkyl; the bonding site of R<1> is 3 or 4] with a compound of the formula R<3> -X<1> (R<3> is a protecting group of phenolic hydroxyl group; X<1> is a halogen) in an organic solvent in the presence of >=1mol (based on 1mol of the esculetin derivative) of a metal carbonate (preferably potassium carbonate).</p> |
