under what circumstances phenol forms phenolate with max yield
High pH - it is a weak acid.
I know it's a weak acid. I need to know circumstances of forming phenolate with max yield
High pH - add excess strong base.
I agree. If you are seeking extremes, you might want to add sodium hydride (a very strong base, not needed to prepare phenolate) instead of the commonly used sodium or potassium hydroxide in tetrahydrofuran under 10°C in a controlled manner.
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