/sci/ - Science & Math

>>7419140
This seems so much better than the barbaric nonsense I had in mind. My idea is more similar to the sublimator you linked. I have two more concerns though:

1) I normally do this reaction on a 20-30g scale, so there will be a lot of material collecting. I intend on just periodically emptying the collection vessel quickly as it fills up -- is this viable?

2) I'm not too familiar with sublimation, but from what I've seen people seem to use it to purify things that are already solid. Would it be problematic if I had my mixture dissolved in some sort of solvent? I've observed this thing subliming at 70C, so I reason that if I use a solvent with a boiling point much higher than 70C then I wouldn't need to worry about it evaporating into the rotovap bump trap.

I'm going to go in today and see if I can try this shit, I'll keep you guys posted. I'm going to be completely ecstatic if this works; I've fucked around with so many methods of purifying this shit and so far the only thing I've found to consistently work was column chromatography, which is not fun at all with large scale reactions like this. It doesn't help that silica slowly decomposes my compound. The first time I did this I had to column 80g, pic related.

>work in a small group, in a cozy but under-funded lab
>our current project basically relies on this precursor galactoside (phenyl β-D-thiogalactoside) as the starting point for all our syntheses
>until now we've been using this big batch that was cooked by this post-doc who left a while ago
>we ran out last month
>I've been tasked with figuring out how to make more
>been trying to get these fucking reactions to work for the past three weeks but the thing keeps anomerizing on me and giving me this disgusting sticky α/β mixture
>everyone's main projects are brought to a halt until we have more of this stuff, they switch to side-projects until I finish this
>pressure is mounting, it's killing me
>ungodly amounts of thiophenol are involved, this shit smells disgusting
>decide to suck it up and run the reactions on a fucking 80 gram scale, finish it off by running my product through this fat column as big as my dick
>Been letting this shit recrystallize in the fridge for a day now, I finally have nice pure fluffy crystals

feels good guys
pic related, monstrous silica column I had to run to separate the α and β. My mixture was about 66% β, and the rest of the reactions were high-yielding so it wasn't too bad (and we have unlimited galactose so it's all good). The rest of the α might come in handy later.