Combine 345 mL of toluene and 30 mL of disulfur dichloride, cool down to -10°C in a freezer. Then start to bubble 20 g of dry ammonia gas with stirring, until red fumes appear to form, keep the temperature below 0°C. Then filter to remove the precipitated sulfur and ammonium chloride. Remove the toluene with a rotovap in the vacuum, recrystallize the crude product with 350 mL of toluene.
S2Cl2 + 16 NH3 = S4N4 + 12 NH4Cl + 8 S