Recently, the small editor is doing a reaction. The literature process is to mix the anhydrous tetrahydrofuran with three fluorohydronhydride and add another raw material at zero degrees Celsius, strictly according to the anhydrous and anaerobic operation, vacuum and nitrogen replacement, repeat 3-5 times, and then injecting anhydrous tetrahydrofuran into the syringe, and cooling the ice water bath to 0-5 degrees. Then three fluoromethanesulfonic anhydride was injected with a syringe.
But when three fluoromethylic anhydride is injected into the flask with a syringe, it is found that the heat release is very severe, the temperature rises rapidly and continues to stir, and the system becomes thicker and thicker, until the end is completely unstirred and turned into a solid, so that the thermometer can not be pulled out. The Internet search, not a definite answer, first suspected of anhydrous tetrahydrofuran open bottle time, high water, exchange a bottle of anhydrous reaction very good use of anhydrous tetrahydrofuran, no change, later suspected of three fluorometric anhydride have problems, the third experiment used new purchase of unsealed unsealed Water tetrahydrofuran (water 50ppm) and new purchase of no three fluoromethylic anhydride, but the final result is a solid, so that can not be stirred and can not continue to add raw materials, more hurried, no quiet heart to look up the literature.
Later, a friend was asked to know that this was a cationic ring opening polymerization of tetrahydrofuran under the catalytic condition of three fluorine sulfonic acid, and the reaction formed polybutanediol oligomers.