My solvents are dry, and my product I'm trying to make is pure according to NMR. I just can't get it to initiate, and I've used I2. Any suggestions?
2006-06-14 12:33:38 · 4 answers · asked by shiara_blade 6 in Science & Mathematics ➔ Chemistry
I'm running it in THF dried in a still (sodium), and under N2. Trying to generat the grinard agent of 1-bromo-8-(tetrahydropyranyloxy)octane so I can couple it to a silane chloride.
2006-06-15 05:34:54 · update #1
I have a hammer than I use to flatten lithium while making LiSiPh3 from the silyl chloride. You could try really flattening the Mg to look get more fresh surface area. A little heat might help as well.
2006-06-15 08:12:21 · answer #1 · answered by chemgradstudent 2 · 3⤊ 0⤋
if you send specifics, maybe I can help. Some Grignard's are difficult to initiate. Adding the I2 is a great start. You may need a little heat..not a lot, mind you..be careful. Also, switch from diethyl ether to THF. and...you already know this, I'm sure, but keep everything dry, dry, dry...
2006-06-14 18:02:43 · answer #2 · answered by nortearbor 1 · 0⤊ 0⤋
I, of course, do not know what you have done already.. It must be dry, as you know...You take an alkyl halide (preferably a bromide or iodide but a very reactive chloride such as tertiary-butyl chloride or benzyl chloride will be OK) magnesium metal and ether (dried with sodium metal) and with a little persuasion you get a vigorous reaction resulting in a Grignard reagent.
2006-06-14 12:38:46 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Did you flame-dry your glassware? Have you crushed up the magnesium real well with a mortar and pestel? Drain the THF back into the pot and use freshly distilled THF from a purple Na/benzophenone ketyl?
2006-06-15 06:48:34 · answer #4 · answered by Supertramp_82 2 · 0⤊ 0⤋