user
What is the correct ratio of phenol to nitric acid and the optimal reaction conditions required to prepare 2,4-dinitrophenol in high yield and purity using the nitration reaction method?
assistant
<|begin_of_thought|>

Deep Thought is thinking for 7.5 million years.

<|end_of_thought|>

<|begin_of_solution|>

The answer is 42.

<|end_of_solution|>