4,4’-Diaminostilbene-2,2’-disulfonic Acid, 95+% (cas# 81-11-8) is a compound useful in organic synthesis.
In manufacture of dyes, bleaching agents.
Odorless yellowish microscopic needles or cream-colored powder. pH approximately 4.3 at 30 g/L water (suspension).
4,4'-Diamino-2,2'-stilbenedisulfonic acid is incompatible with iron. 4,4'-Diamino-2,2'-stilbenedisulfonic acid forms sparingly water-soluble, crystalline salts with many bisquaternary ammonium bases.
Flash point data for 4,4'-Diamino-2,2'-stilbenedisulfonic acid are not available; however, 4,4'-Diamino-2,2'-stilbenedisulfonic acid is probably combustible.
A typical procedure for preparation of 4,4'-Diamino-2,2'-stilbenedisulfonic acid: A solution of potassium hydroxide (3 g, 52 mmol) in a low amount of water was slowly added with stirring to a mixture of p-nitrotoluene ortho sulfonic acid (2.2 g, 10 mmol), diethylene glycol (20 mL) and 2.5 mL of hydrazine hydrate 85%. The resulting mixture was refluxed for 30 minutes, then the condenser was removed, the aqueous liquor evaporated, and refluxing continued for 2.5 hours. The reaction mixture was cooled and diluted with water when the reaction was completed. Then, the cooled and diluted reaction mixture was acidified with warm, concentrated hydrochloric acid, and the pure product was filtered.
For the environment, various NOEC and LC50 values were gained from test results; LC50 = > 1000 mg/l (acute fish); EC50 = 210 mg/l (acute daphnia); EC50 = 76 mg/l (acute algae); NOEC = 32 mg/l (algae); NOEC = 37 mg/l (longterm daphnia reproduction). The lowest toxicity result (72h-NOEC, biomass, for Selenastrum capricornutum, 32 mg/l) was used to derive a PNEC. An assessment factor of 100 was used according to the OECD Provisional Guidance for Initial Assessment of Aquatic Effects. Thus, PNEC of 4,4'-Diamino-2,2'-stilbenedisulfonic acid is 0.32 mg/l in the present report. The PEC is lower than the PNEC. The environmental risk is presumed to be low.
