Phthalocyanines are highly photostable dyes with strong absorption in the red/near-infrared region, making them promising candidates for deep-tissue optical imaging and phototherapy. However, their strong tendency to aggregate in both aqueous and organic media limits practical use. To address this, a non-aggregating phthalocyanine was designed and synthesized by extending the isoindole units with arylmaleimide groups. The incorporation of 2,6-substituents in the aryl groups forces them into an orthogonal orientation relative to the macrocycle, effectively preventing π-stacking and aggregation. In addition to reducing aggregation, maleimide fusion stabilizes the macrocycle’s two-photon active gerade states, resulting in significantly enhanced two-photon absorption (2PA) near 980 nm. A scalable synthetic route to this novel phthalocyanine was developed, and its photophysical properties, including high fluorescence quantum yield and strong 2PA, were characterized. These features establish the new phthalocyanine as a promising platform for developing brain multiphoton imaging probes.