A small quantity of aluminum
chloride (2.7g) was mixed with a 6-fold excess of lithium hydride (4g) under
dry nitrogen in a small round bottomed flask, which was then attached through a
standard ground glass joint to a vacuum system, and evacuated. About 15 ml of
ether was condensed on the reaction mixture at liquid nitrogen temperature. The
reaction, which began as the flask was warmed slowly, was allowed to proceed
vigorously, but was kept under control by cooling the flask with liquid
nitrogen from time to time. The reaction was usually completed in about five
minutes. Filtration of the resulting mixture and removal of the solvent from
the filtrate as previously described yielded a sample of lithium aluminum
hydride adequate for initiation of the reaction of larger batches.
No comments:
Post a Comment