| 摘要 |
<p>There is described a process for the preparation of 5-carboxyphthalide, which comprises adding terephthalic acid to fuming sulfuric acid containing at least 20% by weight of SO3, then adding formaldehyde to the mixture, heating the mixture at a temperature of 120-145 °C and isolating 5-carboxyphthalide from the reaction mixture.</p> |
