I want to convert GO-COOH to CO-COCl by reacting with thionyl chloride. According to literature, 500 mg GO is dispersed in 100 mL thionyl chloride and heated at 70 degree for 12 hour in the presence of 1 mL DMF.
My problem is after reaction is done, how can I get ride of the thionyl chloride? If I use vacuum dry, will it damage the vacuum pump?
Thionyl chloride (SOCl2) can be distilled off the reaction mixture under vacuum, say, by around 40 ºC. As guideline for the required level of vacuum, I have estimated the vapour pressure of SOCl2 as 29 kPa at 40 ºC. You may consider bubbling the non-condensed SOCl2 vapour trough a trap containing cold (or icy) alkaline brine (e.g. NaOH aq.), where both SO2 and HCl can quantitatively dissolve and be neutralized after being generated by the following reaction: SOCl2 + H2O → 2 HCl + SO2. I would suggest to further protect the vacuum pump (e.g. by a filtering system with good adsorption capability). Alternatively, we could dispense such additional protection by substituting a water aspirator (*) for the vacuum pump, as that seems enough to attain a sufficient level of vacuum.
(*) https://en.wikipedia.org/wiki/Aspirator_(pump)
Kangjia, Can you please send me the article for the synthesis?
Thank you.
In my veiw the easy and best way to remove thionyl chloride is by vacuume distillation at temperature lower than 50 degree. Once thionyl chloride is removed again add small volume of toluene and distilled it off so as to remove any traces of socl2.
hi Kangjia Lu
i also did reactions of thionyl chloride by converting R-OH to R-Cl. In my case i was removed excess amount of thionyl chloride by heating up to 80-90 temp. but i always trap the toxic gas.
thank you
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