[benzeen]

Hopefully someone out there with more organic experience than me can help with this one (I am an inorganic chemist by training). Looking for a prep to protect 3-aminopropanol (NH₂CH₂CH₂CH₂OH) with a mono-BOC on the amine. Have read some general preps, but I need to do this at a 500g-1Kg size and don't really want to run columns etc... can anyone suggest a simple "bucket" chemistry prep for this [preferably with a little detail so that I would be able to figure out the prep]?

All suggestion gladly accepted.

Best
BZ

[democanarchis]

I don't think you're going to be able to do this on such a sca;e. Typical BOC protection procedure that I use- 15 ml of a 4:1 mix of anhyrdrous THF:anhydrous methanol per gram of amino alcohol, so for 1Kg you'd want 12L anhydrous THF : 3 L anhydrous methanol. Agitate under nitrogen in an ice bath until internal temperature is < 5 degrees C. Add 3 molar equivalents of Sodium Hydrogen Carbonate (for 1Kg, 40 mols = 3.36 Kg), then immediately add 1.5 molar equivalents of Di-tert-butyl-dicarbonate (for 1Kg, 19.95 mols = 4.354 Kg), and agitate in ice bath (Do not refil- allow to slowly warm to room temperature) until complete by TLC (on a 10g scale ususally left overnight / 16 hours). Concentrate in vacuo to an oil, then column.

To be honest, I would recommend extreme caution and I'd be very hesitant to do this on such a scale. My main concern is the Di-tert-butyl dicarbonate. That stuff is extremely toxic (Toxic +), by inhalation (LD50 mammal 4h 100mg/m3) and by skin contact (LD50 mammal dermal 2mg/kg). I weigh, clean, everything in a fumehood if I'm using it. And thats on a 10/20g scale. If you want to use 4.354 Kg of the stuff, you'd need a dedicated pilot lab with floor length walk in fumehoods, and a full body suit with a full face supplied air respirator.  

The fact that you say you aren't very experienced in organic chemistry also makes me very nervous. Aldrich sell your desired product http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en&N4=416444|ALDRICH&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC for $190 per 50ML. So, $3800 for 1Kg pure. The Di-tert-butyl-dicarbonate alone is going to set you back $234/kg fro mthe cheapest supplier I could find (over $1000, from apollo).

[cundi]

Mainly i agrees with democanarchis.
Have you considered other protecting groups?
How do you obtain the aminopropanol? If you buy it, as i supose, you could consider to buy the corresponding protected compound (not only Boc protection but Cbz, Bn,etc..)