Purchased air pump and tried the method according to the patent:
Took the previous apparatus from my attempt using vacuum, disconnected the vacuum line from the suction trap & connected an air supply line to the reaction flask instead. Assumed most of the MeOH is still unreacted in flask, i.e. didn't make up new batch.
Filled suction trap with NH
4OH soln.
Heated up to ~ 105°C while bubbling air thru.
Suction trap contents started foaming excessively. Swapped the NH
4OH soln for hot water instead (to hydrolyze any DMS that makes it past the condenser, before it gets to my lungs).
Resumed operation at 100-118°C. Condensate came over v. v. slowly. Around 113°C seemed to be optimum.
After about 1.5 hrs there was two layers in the receiver, maybe about 5 ml of water floating on about 1 ml DMS (?).
Don't know exact amounts or yield cos when I transferred to sep funnel it simply left a puddle on the table cos I didn't realise the fucking drain valve was open
!
Also got some of the stuff splashed on me. If I grow another leg out of my waist I'll know why.
[Yes I know, my clandestine chemist's license should be revoked for such incompetence but please be patient with me; I may turn out to be the WOD's equivalent of a suicide bomber]
Okay so I'm gonna try this again, probably with a fresh batch of reactants & minus the idiocy. If it doesn't seem to work well I'll give vacuum another try. If that is also not v. effective, I'll try Halfapint's SO
2/CuCl
2 synth.
Note: Patent recommends an air flow of ~ 5 cubic ft/min/gallon of mixture. In decent units, this is ~ 31 l/min/l (Oz patent IIRC, so I assume UK gallons should be used).
According to the manufacture specs of my air pump, it should deliver 4 l/min. Volume of the reaction mixture ~ 160 ml, so that gives 25 l/min/l, which I think is probably close enough.
what if we take >100 C pet ether (distilled lighter fliud)?I think that the petr. ether may take up the DMS thereby driving the 2nd rctn, but there will still be a water build up, restricting the 1st rctn. Unless both can be removed using the Dean Stark goodie, dunno..