Which listed precursor combines Lithium with Anhydrous Ammonia?

Which listed precursor combines Lithium with Anhydrous Ammonia?

• A. Phenylpropanolamine
• B. Pseudoephedrine
• C. Anhydrous Ammonia
• D. Lithium + Anhydrous Ammonia

Answer: (D)

The key idea is recognizing how certain methamphetamine precursors are produced using reductive chemistry. In a Birch-type reduction, lithium metal in liquid anhydrous ammonia provides solvated electrons that reduce pseudoephedrine or ephedrine into methamphetamine. Because this process requires both lithium and anhydrous ammonia together, the option that lists Lithium + Anhydrous Ammonia is the one describing the reagent system used for this synthesis. The other options refer to ingredients or precursors used in other routes, or describe components without the necessary combination to perform the Birch reduction.

The key idea is recognizing how certain methamphetamine precursors are produced using reductive chemistry. In a Birch-type reduction, lithium metal in liquid anhydrous ammonia provides solvated electrons that reduce pseudoephedrine or ephedrine into methamphetamine. Because this process requires both lithium and anhydrous ammonia together, the option that lists Lithium + Anhydrous Ammonia is the one describing the reagent system used for this synthesis. The other options refer to ingredients or precursors used in other routes, or describe components without the necessary combination to perform the Birch reduction.