Solutions
B PhNH3Cl 2.115 mol/L
PhNH3Cl 16.4338g, H2O 40mL, HCl(conc. aq) 20mL
C NaNO2 4.890mol/L
NaNO2 10.1222g, H2O 30mL
D NaBF4 4.793mol/L
NaBF4 15.6696g, H2O 30mL
Consumption
B 30mL, 0.06345mol PhNH3Cl
C 14.3mL, 0.06980mol NaNO2
D 13.2mL, 0.06345mol NaBF4
Procedure
1. Diazotization
A conical flask contains 30mL B, is equiped with a magnetic stirrer and an ice bath, adjust the bath temperature below 5°. Then add 14.3mL C dropwisely within 15 minutes, drop ice pieces every 5 minutes in order to keep the temperature below 10°. After the adding complete, stir the solution for 7 minutes, and pour in 13.2mL D at once. A layer of light yellow laminar crystals(diazonium fluoroborate) appear. Then stir for another 15 minutes. Filter the precipitates by suction, and leach it with 20mL ethanol and 20mL of aether in turn. 3.5912g of light yellow solid is obtaind, with the yield of 29.6%.
2. Decomposition
Contain the solid obtained in the last step with a 150mL round bottom flask, which is equiped with a condenser and receving apparatus. Heat on one point near the edge of the solid layer with an small flame (eg. alcohol burner). Withdraw the flame as soon as the reaction is initiated. The reaction proceeds spontaneously and smoothly while the solid is melting, bubbling and white smog generating. After the disappearance of the solid, heat the flask and distill the dark-red liquid residue. 1.4mL of colourless, benzene-smelled liquid(fluorobenzene) is obtained, with the yield of 79.9%. The total yield over two steps is 23.6%.


反应式

1、重氮化实验装置 药品（编号和2楼对应）

2、反应进行中 （我放下滴管拍的）
锥形瓶内已有冰块，浴温超过5°也无大碍。

3、加入D溶液（NaBF4）后，析出氟硼酸重氮苯片状晶体

4、用乙醇、乙醚洗涤过并抽干的氟硼酸重氮苯

5、热分解反应装置
用碱液吸收三氟化硼气体

（热分解过程见视频）
6、重氮盐平稳地分解留下的液体
里面总有点水除不干净，有点苯酚夹杂在里面

7、把氟苯蒸出来
液体中还溶有很多三氟化硼，加热的时候还在冒烟。

8、馏出的粗氟苯（量筒测得体积1.4mL）



视频
氟硼酸重氮苯分解反应引发后开拍→固体消失


Discussion
Being stirred with water for long, the newly generated diazonium salt may suffer from nucleophilic attacks in aqueous solution. This may result in the low yield in the 1st step.
Reference
[1]Furniss BS, Hannaford AJ, Smith PWG, Tatchell AR. Vogel's Practical Organic Chemistry [M] 5ed. Vol2, p939
[2]Flood DT, Fluorobenzene, Organic Synthesis [J] Vol2 p295 (1943)


推荐参考读物
[1]Kirsch P. Moden Fluoroorganic Chemistry[M] Wiley-VCH 2004
全文完

SF……
表示外语无力寻求在线翻译中

...看不懂 555

我觉得我还是个小学生。。。。

赞扬有机合成实验 虽然我什么都看不懂……6
三氟化硼挺可怕的…………

[C6H5-N≡N ]+[BF4]-    是一种盐吗、？？

回复：12楼
是盐，称为重氮盐

GJ

赞!今天上午是属于实验党的时间吧!我希望化吧有更多这样的上午!