Tripotassium phosphate

Tripotassium phosphate, also called tribasic potassium phosphate is a water-soluble salt with the chemical formula K3PO4.(H2O)x (x = 0, 3, 7, 9). Tripotassium phosphate is basic.

Production
Tripotassium phosphate is produced by the neutralization of phosphoric acid with potassium hydroxide:

Use in organic chemistry
Tripotassium phosphate has few industrial applications.

It is used as an inert, easily removed proton acceptor in organic synthesis. Some of the reactions are listed below:
 * 1) The hydrate  has been used to catalyze the deprotection of BOC amines. Microwave radiation is used to aid the reaction.
 * 2) As a catalyst for the synthesis of unsymmetrical diaryl ethers using [Bmim] as the solvent. Aryl methane-sulfonates are deprotected and then followed by a nucleophilic aromatic substitution (SNAr) with activated aryl halides.
 * 3) As a base in the cross-coupling reaction of aryl halides with terminal alkynes. It also plays a role in the deacetonation of 4-aryl-2-methylbut-3-yn-2-ol intermediates.
 * 4) As the base in the cross-coupling reaction between aryl halides and phenols or aliphatic alcohols.

Use in foods
Tripotassium phosphate can be used in foods as a buffering agent, emulsifying agent, and for nutrient fortification. It can serve as a sodium-free substitute for trisodium phosphate. The ingredient is most common in dry cereals but is also found in meat, sauces, and cheeses.

Hazards
It is somewhat basic: a 1% aqueous solution has a pH of 11.8.