morsagh
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alcohols test
I need test for secondary alcohols but i can´t use KMnO4 because of positive result on double bond, I don´t have chromates, and there is only a
little of sample so esterification can´t be used too. Please help me.
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gdflp
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Depending on how sensitive you need the test to be, you could try oxidizing the alcohol with a mild reagent, then using 2,4-DNPH to precipitate the
ketone. Won't work if you are expecting the presence of a primary alcohol, ketone, or aldehyde though. Of course, an NMR or IR spectrum would work
as well, depending on what facilities you have access to.
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alexchim
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Lucas's reagent, concentrated solution of ZnCl2 in hydrochloric acid. It is used to identify alcohols, in a test tube, R-OH gives no reaction,
R1R2C-OH gives a slow formation of milky alkyl chloride, R1R2R3C-OH gives an instantaneous reaction of formation of tertiary alkyl chloride.
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Magpie
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Vogel's 3rd edition (forum library) gives some tests for alcohols. Two of them are: 1) make an acetate w/acetyl chloride, and 2) react with Na to
give H2 bubbles.
The single most important condition for a successful synthesis is good mixing - Nicodem
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blogfast25
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Surely unless your suspected alcohol is bone dry that's just begging for a false positive?
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Nicodem
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Thread Moved
25-2-2016 at 07:55 |
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