| 摘要 |
<p>NEW MATERIAL:A 4-hydroxy-2-quinolone derivative of formula I [R<1>-R<5> are H, 1-8C alkyl, halogen, 1-5C alkoxyl, nitro, cyano, 1-3C halogenated alkyl or COOR<6> (R<6> is H or 1-3C alkyl) except when R<1>-R<5> are H at the same time] and a salt thereof. EXAMPLE:4-Hydroxy-3-(2,3,4-trimethoxybenzoyl)-2-quinolone. USE:A medicine such as an antiallergic agent, antitussive and expectorant, remedy for asthma, etc., orally administrable, and having a prolonged duration of drug efficacy. The dose thereof is 1-100mg/day for the oral administration once - in divided three portions. PROCESS:A compound of formula II (R<7> is lower alkyl) is subjected to the ring closing reaction in the presence of a base, e.g. a sodium alkoxide, in a suitable solvent under heating at 50-130 deg.C for 1-10hr to give the aimed compound of formula I .</p> |
