| 摘要 |
Preparation of pure, halogen-free O-phthalaldehyde (OPA) involves hydrolyzing tetrahalo-o-xylene at 155 - 160[deg]C and at a pressure of 2 - 5 bar in presence of phase-transfer catalyst to form o-phthalaldehyde, which is converted in an acidic alcoholic solution at 0 to reflux temperature into corresponding dialkoxyphthalane and, subsequently an acetal cleavage is effected by acid hydrolysis at a pH of 1.5 - 7, resulting in high-purity, halogen-free o-phthalaldehyde. |
