From: Herb Hedgecock (h.hedgec$##$morehead-st.edu)
Date: Thu Jul 01 1999 - 14:31:25 EDT
On Thu, 1 Jul 1999, Matthew J Dowd wrote:
> > I know this is a basic query but any suggestions are appreciated. In
> > our lab, we seem to have difficulty in obtaining dry THF on a consistent
> > basis.
Page 256 of "Organic Syntheses Via Boranes," by H.C.Brown
(Wiley-Interscience) has the following:
Pre-dry the THF over Molecular Sieves (5 A) or calcium hydride for 1-2 d.
Transfer the THF into an inert-atmosphere still by double-ended needle.
Lithium aluminum hydride is added under a blanket of nitrogen in small
quantities using a plastic spatula. Use enough LAH so that a 1-mL aliquot
shows vigorous hydrogen evloluion on hydrolysis with a drop of water.
The THF is heated to reflux with a slow flow of nitrogen through the
system. The nitrogen needle is placed in the bubbler to provide a static
pressure of nitrogen and the THF is collected in the normal manner.
I recommend that you get the book for more details and pictures of the
apparatus. That was the way we purified our THF for hydroboration
solvent, and it stayed pure as long as you excluded oxygen. We had
septum inlet storage flasks and syringes to transfer the material.
Herb Hedgecock, PhD |)runrun |)
Dept of Physical Sciences || run ||
Morehead State University || run ||
Morehead KY 40351 ||run run||
h.hedgec$##$morehead-st.edu || run ||
606-783-2928 ||____run||____
606-783-5002fax (______) (______)
http://www.morehead-st.edu/people/h.hedgec runrunrunrunrunrun
__________________
ORGLIST - Organic Chemistry Mailing List
Website and Archive: http://www.orglist.net/
List coordinator: Joao Aires de Sousa (jas$##$mail.fct.unl.pt)
This archive was generated by hypermail 2.1.4 : Fri Sep 19 2003 - 12:15:04 EDT