tag:blogger.com,1999:blog-8964719845369935777.post8412341774429178284..comments2024-03-27T21:23:40.339-04:00Comments on Chemjobber: Process Wednesday: hexafluoroisopropanol as a reaction solventChemjobberhttp://www.blogger.com/profile/15932113680515602275noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8964719845369935777.post-87640502021396824962012-08-01T22:04:13.029-04:002012-08-01T22:04:13.029-04:00The price of HFIP: we were looking into using it a...The price of HFIP: we were looking into using it as a analytical chromatography solvent (GPC of polymers - it did not unfortunately dissolve our stuff) and the least expensive source on lab scale we found was Oakwood, USD165/kg (the density is 1.6). With distillation -based recycling using heptane as a non-miscible chaser: I would worry about water (from H2O2 - maybe thats why they use anhydrous urea adduct) accumulating in the HFIP after few recycles and slowing down the reaction.<br />A cheaper alternative would be 5:1 formic-acetic acid at 0C, and slightly sub-stoechiometric H2O2 very gradually added, maintaining temperature control is essential for good selectivity and safety (the formic acid -peroxide mix is unstable when heated and can run away). Allyl group epoxidation with a peracid at 0C is quite slow - I have done some peracid oxidations in the presence of allyl protecting group and it survived unmolested.milkshakehttp://orgprepdaily.wordpress.comnoreply@blogger.comtag:blogger.com,1999:blog-8964719845369935777.post-58733302401784413442012-08-01T11:20:29.630-04:002012-08-01T11:20:29.630-04:00First I don't think there is anything that can...First I don't think there is anything that can be called "Green Chemistry".<br />Fluorinated compounds are certainly not green. The water purification system cannot handle them. So if they get into the ecosystem you are %&ç*ed. <br />They may increase reaction rate etc. but I would not entertain them as my first choice.Quintusnoreply@blogger.com