terbutycatechol (TBC) reaction with sulphuric acid

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HARI - 20 Jun 2005 07:50 GMT

i reacted TBC (terbutylcatecol) with NaOH and obtained a phenoxide
salt. the phenoxide salt was then reacted with sulphuric acid in order
to obtain TBC back. what i got was 2 phase separated layers. one was
orange in color and the other was clear liquid. i did an FTIR analysis
and found that the orange layer was TBC and the liquid was natrium
sulphate.

my question is ....

1) can i recover the TBC in a crystal form ?
2) the pH of both the phase separated liquid were around 0.54. why is
it so high ? pH of TBC is 5.5 and the natrium sulphate liquid shouldnt
it have a pH of 7?

if anyone out there have any solution pls reply me at
hariharan.tpm@pengroup.com.my

thank u.

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news - 21 Jun 2005 10:02 GMT

> i reacted TBC (terbutylcatecol) with NaOH and obtained a phenoxide
> salt. the phenoxide salt was then reacted with sulphuric acid in order
[quoted text clipped - 14 lines]
>
> thank u.

1. p-tert-Butyl Catechol is low melting (50C), I would suspect it's also
has a affinity for water (and thereby lowing the melting point), and thus
your layer is a TBC/water one. Test for water content, and if damp then dry
it (azeo dry with toluene maybe)
2. pH is obviously due to excess acid, and if you get a pH reading easily in
the TBC layer then that just confirms the presence of water (pH only works
in water). Sodium sulphate should be 7.

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Namast? - 21 Jun 2005 10:03 GMT

HEY! You've added sulfuric acid, what other pH than 0,5 you expect to
find? I think that this is a good pH. Beside this, what you meassure in
the the TBC phase wasn't pH because the pH is related to the proton
activity in aqueos solution.

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Natural Science Forum / Chemistry / Organic Synthesis / June 2005

terbutycatechol (TBC) reaction with sulphuric acid