A previously reported protocol for the synthesis of the commercial dye [Bu₄N]₂[Ru(4-carboxy-4′-carboxylate-2,2′-bipyridine)₂(NCS)₂] (N719) was thoroughly optimized in terms of the amount of input materials needed, reaction times and temperatures achieving significant reductions in all the three synthetic steps. This optimization allowed a 81% reduction of the Sheldon's E factor of the overall process.