钝化萘衍生物的磺化反应研究

研究了带吸电子取代基的一系列钝化萘衍生物与SO~3进行的磺化反应, 用^1H NMR分析反应混合物的组成.1-萘磺酸以71:20:9的比例产生1,5-, 1,6-和1,7-萘二磺酸, 进一步磺化得到1,3,5-, 1,3,6-萘三磺酸和1,3,5,7-萘四磺酸. 1-萘甲醛的单硫化得到比例为55:9:6:30的5-, 6-,7-和8-磺酸取代物. 1-苯甲酮萘则以83:11:6的比例得到5-,6-,和7-磺酸取代物. 1-硝基萘仅得到5位磺化产物. 1-萘甲酸和1-萘甲酸甲酯得到5位和8位取代产物. 所有的2位取代萘衍生物均先得到5和8位取代产物. 提出了生成SO~3络合物及迫位磺化的历程.

Sulfonation of deactivated naphthalene derivatives

The reaction of sulfur trioxide with deactivated naphthalene derivatives containing an electron withdrawing substituent, viz. -SO3H, -CHO, -COPh, -CO2H, and -CO3Me, in diehloromethane as solvent has been studied by analysis of the resulting mixtures of the sulfo derivatives with 1H NMR. Monosulfonation of naphthalenesulfonic acid yields 1,5-disnlfonie acid (1,5-S2), 1,6-S2 and 1,7-S2. On using a large excess of SO3, the eventual products are 1,3,5-S3, 1, 3,6-S3 and 1,3,5,7-S4. Monosulfonation of 1-formylnaphthalene yields 5-S, 6-S, 7-S and 8-S, in a 55 : 9: 6: 30 ratio, that of 1-benzoylnaphthalene 5-S, 6-S and 7-S in a ratio of 83: 11:6, and 1-nitro naphthalene only 5-S. 1-naphthoic acid and its methyl ester upon SO3 sulfonation and aqueous workup both yield 5- and 8- sulfonaphthoic acid in a ratio of 65: 35 and 77: 21 respectively. The initially formed peri substituted product is the intramolecular anhydride of 8-sulfo-1-naphthoic acid. All the 2- substituted naphthalenes upon SO3 sulfonation yield 5-S and 8-S, of which the former sulfoisomer is far in excess.