Sciencemadness Discussion Board

Sulfuryl/Thionyl Chloride

Agari - 23-12-2015 at 10:09

Sulfuryl chloride is a useful reagent,one use of which is for converting thiols of disulfides into their corresponding sulfenyl chlorides. While it is available on the Internet through sellers such as EBay,it is relatively expensive, with the total price being 37 U.S. Dollars for 25 grams. I plan to prepare SO2Cl2 by first preparing carbon tetrachloride by setting up a TCCA/HCl chlorine gas generator,then bubbling the resulting chlorine through trichloromethane(Chloroform),then preparing sulfur trioxide using the procedure in a publication written by Garage Chemist. The sulfur trioxide will then be placed into an addition funnel connected to a flask containing the CCl4. The amounts will be calculated so that,ideally,the ratio of SO3 to CCl4 is 1:1.91 by mass. The flask will then be connected to another flask filled with a saturated solution of NaOH,and then that will be connected to yet another flask containing KMnO4 to (hopefully) neutralize toxic phosgene gas that is produced. The expected reactions are:
SO3 + CCl4 ---> SO2 + COCl2 + Cl2
SO2 + Cl2 ----> SO2Cl2
SO2 + COCl2 ----> SOCl2 + CO2

COCl2 + 4 NaOH----> 2NaCl + Na2CO3 + 2 H2O (Neutralization of phosgene)

SO2Cl2 and SOCl2 react violently with water,it is advised to dry the reagents before use.

Criticism is welcome.
Edit:Bubbling chlorine gas through chloroform produces hydrochloric acid,but can be removed by dissolving the HCl in water,carbon tetrachloride is denser than water,and so will sink,and can be separated.

[Edited on 23-12-2015 by Agari]

Magpie - 23-12-2015 at 10:22

I have made both SO3 and CCl4. The CCl4 synthesis is quite facile if you have the right equipment. You can read my post on this synthesis on this forum.

I think you are in for some adventures. Best wishes!

DraconicAcid - 23-12-2015 at 10:27

Wouldn't it be easier to directly react dry SO2 with dry Cl2?

Agari - 23-12-2015 at 11:08

After reading up on some older posts on the forum,I think I found a less toxic alternative for thionyl/sulfuryl chloride synthesis. Now that I know the method for SO2 and SCl2 generation,this method is no longer neccessary.