Sciencemadness Discussion Board

IPA and peroxides

FriendlyFinger - 3-7-2005 at 01:35

What's the story here? How dangerous is IPA? Swim has some IPA that was used to recrystalise MeNH2.HCL and want's to recycle by drying and distilling. Vogles points out that IPA should have peroxides removed before dehydrating. So is the peroxide story the same with every solvent; dangerous to distill to dryness?

Swim tried this; disolved 200mg KI and made up to 2ml with dH2O, mixed this with 1ml of dilute HCL (1;5) added 6 drops of starch solution then imediately dropped in 1ml IPA that was sitting in a beaker for 3 days and used to extract MeNH2.HCL. It did not turn purple, why not? It turned light gold.

Swim tried it on an older batch, but same thing. Was the test not performed properley?

How about just drying with MgSO4, filtering and using this IPA to recrystalise. Will some MgSO4 get through to contaminate the MeNH2.HCL?

Kind regards,

FF

Madandcrazy - 10-7-2005 at 07:01

Whats the IPA FriendlyFinger ?

The chemical MeNH2.HCL seems to be of interest for normal chemical reaktions.
(looking for 1,3-chloroamidoethylene ;) )

Polverone - 10-7-2005 at 12:23

IPA is isopropyl alcohol. It has been reported to form peroxides, but it does not do so easily. The negative test for peroxides on old IPA is unsurprising.

Sandmeyer - 19-7-2005 at 19:31

what, is this true? i didn't know IPA can form peroxides, shouldn't in that case alcohols generally do so, how is this supposed to happen?

[Edited on 20-7-2005 by Sandmeyer]

S.C. Wack - 19-7-2005 at 20:55

Alter ego post:

https://www.synthetikal.com/synthforum/about1265.html