Name | Benzidine |
Synonyms | Benzidine C.I. 37225 4,4'-bianiline benzydyna(polish) 4,4'-Diaminobiphenyl 4,4'-diamino-bipheny 4,4'-diaminodiphenyl biphenyl-4,4'-diamine Biphenyl,4,4'-diamino- 4,4'-biphenylenediamine biphenyl -4,4'-ylenediamine [1,1'-Biphenyl]-4,4'-diamine 4-(4-aminophenyl)benzenamine C.I. Azoic Diazo Component 112 |
CAS | 92-87-5 |
EINECS | 202-199-1 |
InChI | InChI=1/C12H12N2/c13-11-5-1-9(2-6-11)10-3-7-12(14)8-4-10/h1-8H,13-14H2 |
InChIKey | HFACYLZERDEVSX-UHFFFAOYSA-N |
Molecular Formula | C12H12N2 |
Molar Mass | 184.24 |
Density | 1.25 |
Melting Point | 127-128°C |
Boling Point | 402°C |
Flash Point | 11°C |
Water Solubility | Sparingly soluble. <0.1 g/100 mL at 22 ºC |
Solubility | Soluble in ethanol (U.S. EPA, 1985) and ether (1 g/50 mL) (Windholz et al., 1983) |
Vapor Presure | Based on the specific vapor density value of 6.36 (Sims et al., 1988), the vapor pressure wascalculated to be 0.83 at 20 °C. |
Appearance | neat |
Color | Grayish-yellow, crystalline powder; white or sltlyreddish crystals, powder |
Exposure Limit | Because it is a carcinogen and readilyabsorbed through skin, no TLV has beenassigned. Exposure should be at an absoluteminimum.Recognized Human Carcinogen (ACGIH);Human Carcinogen (MSHA); Carcinogen(O |
Merck | 13,1077 |
BRN | 742770 |
pKa | 4.66(at 30℃) |
Storage Condition | 2-8°C |
Stability | Stable. Combustible. Incompatible with strong oxidizing agents. |
Refractive Index | 1.6266 (estimate) |
Physical and Chemical Properties | White or reddish crystalline powder. Melting point 125 ℃, boiling point 400 ℃,(98.7kPa), relative density 1.250(20/4 ℃), soluble in boiling ethanol, acetic acid and dilute hydrochloric acid, slightly soluble in ether, slightly soluble in boiling water, very slightly soluble in cold water. The color darkens in the air and light. Analytical reagents are usually benzidine hydrochloride or acetate with higher solubility, and sulfate is usually used in industry. Benzidine acetate is white or nearly white crystals, soluble in water, acetic acid and hydrochloric acid, and used as an indicator [36341-27-2]. benzidine hydrochloride [531-85-1]. Benzidine sulfate is a white crystalline powder or small scale-like crystal, soluble in ether, very slightly soluble in water, dilute acid and alcohol [21136-70-9]. |
Risk Codes | R45 - May cause cancer R22 - Harmful if swallowed R50/53 - Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R52/53 - Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R39/23/24/25 - R23/24/25 - Toxic by inhalation, in contact with skin and if swallowed. R11 - Highly Flammable R36/37/38 - Irritating to eyes, respiratory system and skin. R20/21/22 - Harmful by inhalation, in contact with skin and if swallowed. R51/53 - Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R67 - Vapors may cause drowsiness and dizziness |
Safety Description | S53 - Avoid exposure - obtain special instructions before use. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S60 - This material and its container must be disposed of as hazardous waste. S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S36/37 - Wear suitable protective clothing and gloves. S16 - Keep away from sources of ignition. S7 - Keep container tightly closed. S36 - Wear suitable protective clothing. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
UN IDs | UN 1885 6.1/PG 2 |
WGK Germany | 3 |
RTECS | DC9625000 |
FLUKA BRAND F CODES | 8 |
HS Code | 29215900 |
Hazard Class | 6.1(a) |
Packing Group | II |
Toxicity | Acute oral LD50 for mice 214 mg/kg, rats 309 mg/kg (quoted, RTECS, 1985). |
colorless crystals. Turn yellow or reddish brown in light or in the air. Highly toxic. Soluble in acetic acid and dilute hydrochloric acid, soluble in hot water, slightly soluble in water, ethanol, ether. 1g of the Prolo in 2500ml of cold water, 107ml of boiling water, 5ml of boiling alcohol, 50ml of ether. Corresponding salts are formed with inorganic acids. Flammable in case of open flame and high heat. A chemical reaction may occur in contact with a strong oxidizing agent. Toxic nitrogen oxide smoke is released by thermal decomposition.
nitrobenzene is reduced in an alkali solution with zinc powder to be a symmetrical diphenylamine, and then the molecule is rearranged in a hydrochloric acid medium to be benzidine hydrochloride, and then liquid alkali is added to form a free radical.
used as a chain extender in the production of polyurethane rubber and fibers. It is also an intermediate of organic synthesis and azo dyes, which can be used to prepare Direct Dark Brown M, direct green, direct dark green B and azo comprehensive organic pigments. Also used in medicine and chemical reagents.
rat oral LD50;309mg/kg. Flammable, toxic, irritant. Benzidine can enter the body through the respiratory tract, gastrointestinal tract, skin. On the skin can cause contact dermatitis, irritation of the mucosa, long-term contact can cause hemorrhagic cystitis, recurrent papilloma of the bladder and bladder cancer. The International Center for Research on Cancer (IARC) has been identified as a carcinogen. Staff should be protected.
Henry's Law Constant | (x 10-11 atm?m3/mol):3.88 at 25 °C (estimated, Howard, 1989) |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
(IARC) carcinogen classification | 1 (Vol. 29, Sup 7, 99, 100F) 2012 |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
uses | important dye intermediates, benzidine and its derivatives can be used in the manufacture of direct dyes, acid dyes, vat dyes, ice dyes, sulfur dyes, reactive dyes and organic pigments. There are more than 250 dyes made from benzidine, the most important of which is direct black EW, which is a widely used organic pigment. |
production method | hydrogenated azobenzene is generated by reduction of nitrobenzene and then obtained by rearrangement. In industrial production, the hydrogenation of azobenzene rearrangement via benzidine hydrochloride, and then concentrated sulfuric acid obtained benzidine sulfate. |
category | toxic substances |
toxicity grade | high toxicity |
Acute toxicity | oral-rat LD50: 309 mg/kg; Oral-mouse LD50: 214 mg/kg |
flammability hazard characteristics | flammability; Thermal decomposition of toxic nitrogen oxide gas; Hemolysis due to poisoning, myelosuppression; Food Nausea, Vomit, injury to liver and kidney |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; It is stored separately from oxidants and food additives |
fire extinguishing agent | foam, water, carbon dioxide, sand |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |