[Johte]

It was suggested to me that at the micro-milli scale the acid wash wouldn't be dangerous.

I attempted in pyridine and lost the product when trying to remove pyridine in vacuo. I retried replacing the pyridine with methanol. I'm also still learning how much silica to use per g product. I was told as a general rule 25-30 g silica / 1 g product. With that ratio and just hexane, there was multiple co-elutions and still at that none of them seemed to correlate to a higher polarity species of starting material.

I used PMA wash and I₂/silica jar to develop the plates. I have no doubt that most of my problems come down to my technique. I'm just trying to pinpoint where my issue is.

[discodermolide]

Really the best method is change to DCM/H₂O or toluene/water, may be better as separation and work-up are easier. Good stirring and use tetra-n-butylammonium bromide as phase transfer catalyst. Sodium azide dissolved in water with catalyst keeping the pH around 9 should avoid any HN3 formation, halide in organic.
For work-up just separate organic, water wash if required and remove solvent. Or just do your next reaction in that solvent.

[Johte]

Alrighty discodermolide,

I have ordered the TBABr. Would you have literature on this route so my only reasons for going this route arn't "some guy on the internet."

[discodermolide]

I have a method for benzyl azide preparation, which I know is applicable to aliphatic azides. PM me with a e-mail and I will send it to you.