Difluoromethanesulfonic acid Part II. A two-step route to the free acid from monohydrated sodium difluoromethanesulfonate
作者:Bernard R. Langlois
DOI:10.1016/s0022-1139(00)80440-6
日期:1990.6
Anhydrous difluoromethanesulfonic acid (“diflic acid”) can be obtained, in a two-step procedure, from monohydrated sodium difluoromethanesulfonate, a very stable salt not easily dehydrated. In the first step, stable hydronium difluoromethanesulfonate is distilled from a mixture of CHF2SO3Na,H2O and pure sulfuric acid in a 86 % yield. In the second step, diluted oleum (10 % S03), containing a slight
无水二氟甲磺酸(“二氟酸”)可通过两步过程,由一水合的二氟甲磺酸钠(一种非常稳定的盐,不易脱水)制得。在第一步中,从CHF 2 SO 3 Na,H 2 O和纯硫酸的混合物中蒸馏出稳定的二氟甲烷磺酸水合盐,收率为86%。第二步,稀释的发烟硫酸(10%S0 3将含有稍微过量的三氧化硫的)缓慢滴入二氟甲磺酸氢盐中,并从生成的混合物中蒸馏出无水二氟甲磺酸,收率为51%。使用更浓的发烟硫酸和过量的三氧化硫会导致气态产物相当剧烈地分解,为此提出了链机理。调用相同的方法来解释用亚硫酰氯观察到的二氟甲烷磺酸氢盐的更剧烈的降解。该链反应似乎受α-酸性氢形成氢键的强大能力支配。