DPT synth Q

[Bandil]

Hi!

Swim was dreaming of some legal DPT He followed TiHKAL to the letter, except he scaled up X5 with everything. The soln looked nice and reddish/brownish and kept getting darker by the hour. After 12 hours a LOT of white crystals suddenly precipated out of the soln and they just kept coming. At 40 hours reaction, the precipation has stopped, but the reaction vessel is quite full of pretty yellowish crystals. Now for the question:

TiHKAL does not mention precipation at this stage, but swim supposes that it is simply the diisoproylethylamine base, that has precipated as the iodide salt right? Swim was thinking og discarding the white sludge and exctracting on the remaing soln. Is this right, or should everything go into the A/B extraction?

Please resond ASAP, as swim is quite near the end of his dream!

Thanks a lot!

Regards
Peter

[Lilienthal]

Wrong!

Although diisopropylethylamine is the stronger base, the precipitate may not be elusively diisopropylethylammonium iodide. Do a B or B/A/B extraction and have fun removing the diisopropylethylamine...

[Bandil]

and how would i remove the diisopropylethylamine? Can it be distilled away?

[Rhodium]

Yes, diisopropylethylamine has a much lower boiling point (127°C at standard pressure) than DPT (145-155°C at 0.08 mmHg).