| 摘要 |
<p>A process for producing an alkyl ester of 6,7-difluoro-4-hydroxy-2-mercaptoquinoline-3-carboxylic acid, represented by general formula (I), efficiently in a fewer steps by the ring closure of a compound represented by general formula (II) in the presence of a base, wherein R?1 and R2¿ may be the same or different from each other and each represents alkyl.</p> |
