| 摘要 |
<p>Disclosed herein is an improved process for preparing 1RS-3 min -RS epimer of aminophthalideisoquinolines represented by the general formula (I): <CHEM> wherein R<1> and R<2> independently represent hydrogen atom or a lower alkoxy group, R<3> is a lower alkyl group, and R<4>, R<5> and R<6> independently represent a lower alkoxy group. The improvement comprises, in the first step of reacting trihydroxybenzoic acids with dialkyl sulfates, maintaining the pH of aqueous reaction media in the range of from 8.5 to 11, inclusive, by the addition of a caustic alkali.</p> |
