Author Topic: Borohydride Reduction Colours  (Read 1408 times)

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pooky

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Borohydride Reduction Colours
« on: September 20, 2003, 06:43:00 PM »
P decided to try LaBTop's borohydride reduction,following the protocols and updates found on TFSE.Was interesting,when NaBH4 was added,the colour of the solution would change from a red/burgundy to a pale yellow.When the bubbling stopped,it would go back to the wine colour.After all the NaBH4 was added, the flask was vented with a stopper and a tube, out the window,and remained wine coloured for a while before going back yellow.P put a little spit on the tube end,and gas is evolving slowly.After an hour,P decided to check the temperature, and the solution turned to wine within a few seconds.Hmmm.Within 15 minutes after putting the stopper and vent back in,it was yellow again.Six hours later,P repeated,and the same thing happened.P is guessing there is some sort of oxidation going on...is this a normal state of affairs??P will let it stir for a day or when the gas stops evolving,and see what happens.Anyone? Appreciate a clue..

pooky

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« Reply #1 on: September 21, 2003, 02:00:00 AM »
P finished the reduction, and did the workup.From 120g ketone,P got 100g of a clear (with the smallest hint of yellow)bitter tasting sharp smelling liquid,that distilled just a few degrees higher.Does this sound OK? Thanks..

abolt

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« Reply #2 on: September 22, 2003, 04:27:00 AM »
A wise Bee once told me that you never judge a reaction by it colors.