甲醇盐

In the second step K2SO4 can be obtained from potassium bisulfate by means of desalting with methanol.

第二步就可以使用甲醇对硫酸氢钾脱盐，然后从中获取硫酸钾。

Optimum conditions are as follows: DMF is used as solvent, compound quaternary ammonium salt as catalyst, n(p-nitrochloro benzene):n=1: 1.2, m:m(p-nitrochloro benzene)=4%, m:m(p-nitrochloro benzene)1:1, and reacted under 155~160℃ for 18 h; reduction reaction is carried out in methanol with Raney nickel, which is used as catalyst; the raw product is added an antioxidant, and distilled simply under reduced pressure to obtain 4-fluoroaniline with excellence quality, purity is over 99.5%, total yield is 89.3%.

实验结果表明，氟化反应的最佳条件为：二甲基甲酰胺为溶剂、复合季铵盐为催化剂，n：n=1：1.2，m（催化剂：m=4%，m：m=1：1，于155~160℃下反应18h；还原反应在甲醇中进行，以阮内镍为催化剂；粗产品加入抗氧剂，减压条件下简单蒸馏得高品位的对氟苯胺。

I can not make it blossom and suits me

我不能让树为我开花

When temperatures are above approximately 80 °C discolouration of the raceways or rolling elements is a frequent feature.

当温度高于 80 °C 左右时，滚道或滚动元件褪色是很常见的特征。