The TEG is just a solvent, other solvents should work, but that allows easy heating to high temps. The Sodium Dithionate is a reducing agent, which reduces the 3-nitro group to a 3-amino group. This could also be done with hydrogenation, tin or iron in HCl, or a variety of other reducing agents, but Sodium Diothionate is very safe and easy to use, with no heavy metals or major fire hazards. I did that reaction many years back myself. Gotta love glowing stuff. Do you oxidize the luminol with NaFe(CN)6 and hydrogen peroxide?
Bob