Phenol, 2,4-dinitro-, sulfurized, leuco derivs.

Preparation

2,4-Dinitrophenol?or its Sodium salt (by?1-Chloro-2,4-dinitrobenzene?alkaline hydrolysis)??and Sodium polysulfide heating, in 110 ~ 120 ℃ reflux heating 48 to 72 hours, or in 130 ~ 140 ℃ under pressure to short time heating, then dilution melt, adding acid or air oxidation make dye completely precipitated out. In the molten material to the intermediate Sodium polysulfide proportion must be appropriate, such ability in reaction end solution almost no dye residual.

Properties and Applications

green black and blue black. Black uniform powder. Insoluble in water and Etanol. In the Sodium sulfide solution solubility is good, for green black; Add Sodium hydroxide and Sodium sulfide solution of colour and lustre is blue; Add hydrochloric acid Sodium sulfide solution to have green black precipitation; In the cold part of concentrated sulfuric acid solution, after heating for deep green light blue, further heating into dark blue; In 25% of fuming sulfuric acid for black blue, dilution after green black precipitation.