Transmute: Primal Mana to Fire
From WoWWiki
Transmute: Primal Mana to Fire allows an alchemist to change a [Primal Mana] into [Primal Fire]. This requires a [Philosopher's Stone] and triggers a 20-hour transmute cooldown.
Source
This is a rare transmute that does not have a recipe. The only way to learn it is to "discover" it.
Alchemy Discovery:
You have a small chance to discover a recipe from a specific list of discoverable recipes every time that you perform a transmutation or that you make a potion, elixir, or flask that was introduced in the Burning Crusade. The discovered recipe is learned automatically. Non-factors include physical location, level, and skill level.

