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The reason to use a PTC is to have the anion...
Lilienthal:
The reason to use a PTC is to have the anion in the organic phase aided by the PTC. Therefore is doesn't make sense to add the base dropwise.
Biphasic reactions have to be heavily stirred, otherwise the reaction rate will drop dramatically.
descent:
I know very well what is PTC, but I am sure that TEBA will easily extract the MONO-anion, but not so easily the DI-anion of hydroquinone. My idea is to start with 1 eq NaOH which is enough for the reaction to begin, and then gradually add more base for the second hydroxyl.
And I know that such reaction are usually - but not always - stirred, and I still hope to know: Did hest used mixing? Because my magnetic stirrer is far from being perfect.
hest:
Yes I used a MagStirr with a big magnet. Mixin is werye important.
Why tune a 80% reaction _ the starting materials is free. Use your pover on the grignard step.
descent:
Thanks! I will use my biggest magnet. I have the intention to mix a 1.5 l mixture, to prepare a suffisant amount of you know what, and use all my power on the cyclization step. I plan to try cyclization in a planetary ball mill with Mg, Zn, Li, Na ... It sounds crazy but "crazy experiments lead to Nobel or to nothing" (Erasmus Darwin).
hest:
I plan to try cyclization in a planetary ball mill with Mg, Zn, Li, Na
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Sodium in a ball mill, I would love to see that. Might add some permanganate ;)
Have fun
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