IPA and peroxides

Friendlycat · Sun Jul 03, 2005 2:29 pm

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,

FC

Vitus · Psychoscientist

isopropanol? peroxides??

You probably are referring to isopropyl ether, which forms peroxides fast. no?

Vitriodor · Tue Jul 05, 2005 3:46 am

Hmm, Android closed this topic at Wetdreams....

joe_aldehyde · huxleys associate

i had nothing to say so i posted here

braindamage · Tue Jul 05, 2005 8:24 pm

^chill.i think that he may have read that evaping ipa WITH peroxides is dangerous,you can often see this in the eng manuals,peroxides&heat&air=boom,blah,blah
its better to ask than to think youre smarter than jove and go for a darvin award

bio · Working Bee

Organic Reactions
VOLUME II

EDITORIAL BOARD
ROGER ADAMS, Editor-in-Chief
WERNER E. BACHMANN JOHN R. JOHNSON
LOUIS F. FIESER H. R. SNYDER

ASSOCIATE EDITORS
T. A. GEISSMAN
CLIFF S. HAMILTON
ALBERT L. HENNE
A. W. INGERSOLL
ERNEST L. JACKSON
WILLIAM S. JOHNSON
NATHAN KORNBLUM
D. STANLEY TARBELL
A. L. WILDS

5. REDUCTION WITH ALUMINUM ALKOXIDES (THE MEERWEIN-PONNDORF VERLEY
REDUCTION)—A. L. Wilds ' 178

198 REDUCTION WITH ALUMINUM ALKOXIDES

Recovery of the -Isopropyl Alcohol

Because of the low cost of isopropyl alcohol it is usually not economical
recover the solvent. However, .if the isopropyl alcohol is to be recov

ered, caution must be exercised in working with it, particularly if it had
been allowed to stand for several days. It is essential to test for the
presence of peroxides, which form readily in the impure isopropyl
alcohol-acetone mixture.61' * The literature records 62 a serious explosion
during the distillation of a mixture of isopropyl alcohol and acetone
(recovered from the reduction of crotonaldehyde) which had aged for
a year. Any peroxides that are present can be removed conveniently by
using stannous chloride M before drying and distilling the recovered
isopropyl alcohol, f

* To test for peroxides add 0.5 cc. of the isopropyl alcohol to 1 cc. of a 10% potassium
iodide solution acidified with 0.5 cc. of dilute (1 : 5) hydrochloric acid. The test is positive
if the yellow color of liberated iodine appears in one minute; it is still more sensitive if a
few drops of 2% starch solution are added to this iodine solution to give the blue-black
starch-iodine color.
t To remove the peroxides add 10 to 15 g. of solid stannous chloride for each liter of
recovered isopropyl alcohol and reflux for one-half hour. A portion of the solution on
cooling should no longer give a positive test with acidified potassium iodide even on the
addition of starch solution. If any iodine is liberated additional 5-g. portions of stannous
chloride should be added and refluxing continued until the test' le completely negative.
Calcium oxide is then added; the mixture.is dried by refluxing for several hours and distilled.
The first portion of the distillate is discarded until the test for acetone is negative
(p. 200). Peroxides usually redevelop in this purified isopropyl alcohol in several days.
t Adapted (reference 37) from procedures by Lund (reference 5) and Young, Hartung,
and Crossley (reference 13).
61 For the formation of peroxides in pure isopropyl alcohol see Redemann,*/. Am. Chem.
Soe., 64, 3049 (1942). The possibility that the peroxide is trimolecular acetone peroxide
has been pointed out by Acree and Haller, ibid., 65, 1652 (1943).
" Wagner-Jauregg, Angew. Chem., 52, 709 (1939).
68 Stannous chloride has been used to remove peroxides from dioxane and ether, Fisher
and Baxter, Colo. School Mines Mag., 30, 447 (1940)[C. A., 34, 8111 (1940)].
M Wislicenus and Kaufmann, Bar., 28, 1323 (1895).
85 Adkins, J. Am. Chem. Soe., 44, 2178 (1922-).

Star-light · Blacklight bulb

primathon · modified

Joe, I think you'd better re-check your sources, as you flat-out contradict Google on this one: isopropyl alcohol peroxide formation. We wouldn't want anybody blowing their ass up and pointing the finger, now would we?

Vitriodor · Wed Jul 13, 2005 1:32 am

bio · Working Bee

Hmmmmmmmm....... seems like I better test the RA IPA 99.5% .2% water I just picked up for less than the tech grade price!

It has been sitting, unopened, at the suppliers for about 18months. He gave me a deal I couldn't refuse so picked up a few gallons.

Didn't quite realize how sensitive this stuff really is until a couple weeks ago when reading the OR article in preparation for making some Al Isopropoxide.

A little off topic but I think maybe CCl3 could be used in lieu CCl4 which is the recomended catalyst in this reaction?? Anyone have experience with this?? Have to do something with all this granulated Aluminum! Wink

hahas · Fri Jul 15, 2005 8:54 am

i see that in the rush to call bullshit, no one bothered to actually look in Vogel (p 886 3rd ed), like FC said.

the articles mentioned above...the first page of JACS articles prior to 1996 are free, as OCR'd pdf. i could give the direct link to the pdf, but if you didn't know that, you'll probably like this link better:

http://pubs3.acs.org/acs/journals/toc.page?incoden=jacsat&indecade=6&involume=64&inissue=12

most of the article is on page 3049, and note that you can get page 3050 as well, just as another pdf. the later AP article is available in full also - both articles are very short.

it's hilarious that you can get page 2968 this way from the above link, and the last page of the article, 2970 - and read them without having any clue that P2P is made twice. but the yields were only <13-16%, based on the Grignard reagent.

note that the same first page thing, from the beginning to 1995, also applies for:

Accounts of Chemical Research
Analytical Chemistry
I&EC Analytical Edition (1929-1946)
Biochemistry
Bioconjugate Chemistry
Biotechnology Progress
Chemical & Engineering News
Chemical Research in Toxicology
Chemical Reviews
Chemistry of Materials
Energy & Fuels
Environmental Science & Technology
Industrial & Engineering Chemistry Research
I&EC (1909-1970)
I&EC Fundamentals (1962-1986)
I&EC Process Design and Development (1962-1986)
I&EC Product Research and Development (1962-1986)
Inorganic Chemistry
Journal of Agricultural and Food Chemistry
Journal of Chemical & Engineering Data
I&EC Chem and Eng Data Series (1956-1958)
Journal of Chemical Information and Modeling
(formerly Journal of Chemical Information and Computer Sciences)
Journal of Chemical Documentation (1961-1974)
Journal of Medicinal Chemistry
Journal of Natural Products
The Journal of Organic Chemistry
The Journal of Physical Chemistry (1896-1996)
Langmuir
Macromolecules
Organometallics

http://pubs.acs.org/about.html