| 摘要 |
PURPOSE:To obtain a compound useful as a raw material for dye intermediates and condensation resin monomer in high purity and yield, by sulfonating 2- methylnaphthalene with an almost equimolar amount at a high temperature and subsequently carrying out steam distillation, cooling and separation of a crystallized material. CONSTITUTION:One mol 2-methylnaphthalene is reacted with 0.8-1.3mol, preferably 0.9-1.1mol concentrated sulfuric acid at 120-170 deg.C for 1-5hr, preferably at 130-150 deg.C for 2-3hr to give a sulfonated material containing 2- methylnaphthalene-6-sulfonic acid at >=85% formation ratio in >=85% conversion. The resultant sulfonated material is then subjected to steams distillation at 110-130 deg.C for 1-2hr to distil away the unreacted 2-methylnaphthalene and the residual solution is cooled to separate the crystallized material and afford the aimed substance.
|
