Inkjet technology using pigment requires pigment dispersity as well as the stability in solvents. New synergist PY-150ASA2 was synthesized by substituting 1,4-butane sultone in order to give the dispersity and the stability. The original pigments showed very low solubility in water and organic solvents. PY-150ASA2 has better solubility and stability in water compared to the pigment. Through the storage stability test, PY-150ASA2 disperses well in the pigment and has a smaller particle size than that of the solsperse 22000, a commercialized synergist. Synergest is expected to be applied to pigment inks for the improved performance.