What is the best way to do this reaction to form the dichloride as an reactive intermediate when the substituent R is acid sensitive?
In the literature the reaction is either performed with PCl5, a mixture of POCl3 and PCl5, SOCl2 or Oxalylchloride + TMSBr. This goes for ethyl or isopropyl moieties, I also saw an example for benzyl. I think my best shot would be SOCl2 which is as I know more reactive than oxalylchloride and because it is a liquid, while PCl5 (can't be evaporated so easy) is a solid and my compound may not be stable to TMSBr, because it is suspected to be sensitive to TMS+ cation.
All of these reagents will generate acid when they have contact to trace water. These reactions are all performed under schlenk conditions, still usually I see back reactions to the hydrolysis product. Is the only viable strategy to remove the excess of chlorination agent in vacuo or is there the possibility to perform a quenching step that does not release acid while keeping the dichloride intact?
For example when I use oxalyl chloride, to produce an phosphorus acid chloride, the removal at the rotivap is often not complete. I doubt, that there is the possibility to perform this reaction from the start under basic conditions?
