There are some interesting laboratory reactions that use liquid ammonia as a solvent (for example, the Birch Reduction where an alkali metal is dissolved in liquid ammonia).
There have also been some high volume industrial processes that use liquid ammonia as a solvent (the weedkiller paraquat has two, quite different, production routes using liquid ammonia producing thousands of tonnes a year). One uses dissolving sodium (like the Birch reduction):
But are there any other significant chemical manufacturing processes that use it?
NB I would include the production of pharmaceuticals or their ingredients as well as any bulk chemicals.