Tetrabutylphosphonium hydroxide (TBPH) can be used: • To convert poorly water-soluble acidic APIs into TBP ionic liquids (IL). • As a cation source in the synthesis of Good′s buffer ionic liquids (GB-ILs) via an acid−base neutralization reaction with Good′s buffer anions. • To synthesize tetrabutylphosphonium acetate, which along with Cu2O-nanoparticles forms an excellent catalyst system for protodecarboxylation reactions Tetrabutylphosphonium hydroxide (TBPH) can be used: • To convert poorly water-soluble acidic APIs into TBP ionic liquids (IL). • As a cation source in the synthesis of Good′s buffer ionic liquids (GB-ILs) via an acid−base neutralization reaction with Good′s buffer anions. • To synthesize tetrabutylphosphonium acetate, which along with Cu2O-nanoparticles forms an excellent catalyst system for protodecarboxylation reactions