1,2 -phenylenediamine

Other Names o-Phenylenediamine 1,2-Diaminobenzene l,2-Phenylenediamine 2-Aminoaniline C.I. 76010 C.I. Oxidation Base 16 IK 3 IK 3 (amine) NSC 5354 Orthamine o-Aminoaniline o-Aminophenylamine o-Benzenediamine o-Diaminobenzene CA Index Name 1,2-Benzenediamine CAS Registry Number 95-54-5 Merck Index Number 7284 Chemical Structure 

Chemical/Dye Class Fluorescent Molecular Formula C6HgN2 Molecular Weight 108.14 pH Range 3.1. 4 

Solubility Slightly soluble in water freely soluble in ethanol, ether, chloroform Melting Point 103-104°C Boiling Point 256-258°C Synthesis Synthetic methodsi  

Major Applications Bottom antireflective coatings, saniconductor devices, hair dyes, detecting antibody,glucose,i streptomycm,i4 penicillm,i5 sulfonamide,i neuroglobin,i2 substrate for horse radish peroxidasei  

Safety/Toxicity Acute toxidty,i aquatic toxicity,2o carcmogenicity,2i chemical toxicity, hepato-toxicity,23 cytotoxicity,23 genotoxicity, mutagenicity,25.26 oral toxicity, percutaneous toxicity, phytotoxicity29 

Compounds containing two primary amino groups attached to a benzene ring can be prepared by the reduction of dinitro compounds and of nitroanilines, usually with tin or stannous chloride and hydrochloric acid or with iron and very dilute hydrochloric acid. Pam-diamines may also be obtained by the reduction of aromatic amino-azo compounds (e.g., p-aminodimethylaniline from methyl orange, see Section IV,78). p-Phenylenediamine may also be prepared from p-nitroacetanilide reduction with iron and acid yields p-amino-acetanilide, which may be hydrolysed to the diamine. 

Experimental details are given for o-phenylenediamlne, which is conveniently prepared by the reduction of o-nitroanUine in alcoholic sodium hydroxide solution wi zinc powder  

MISCELLANEOUS COMPOUNDS DERIVED FROM PRIMARY AMINES 

Thiocarbanilide is prepared by heating a mixture of aniline and carbon disulphide in absolute ethyl alcohol  

In a 1 litre round-bottomed flask provided with an efficient double surface condenser, place 40 g. (39 ml.) of aniline, 50 g. (40 ml.) of carbon sulphide CAUTION inflammable) (1), and 60 g. (63-6 ml.) of absolute ethyl alcohol (2). Set up the apparatus in the fume cupboard or attach an absorption device to the top of the condenser (see Fig. II, 8, 1) to absorb the hydrogen sulphide which is evolved. Heat upon an electrically-heated water bath or upon a steam bath for 8 hours or until the contents of the flask sohdify. When the reaction is complete, arrange the condenser for downward distillation (Fig. II, 13, 3), and remove the excess of carbon disulphide and alcohol (CAUTION inflammable there must be no flame near the receiver). Shake the residue in the flask with excess of dilute hydrochloric acid (1 10) to remove any aniline present, filter at the pump, wash with water, and drain well. Dry in the steam oven. The yield of crude product, which is quite satisfactory for the preparation of phenyl wo-thiocyanate (Section IV,95), is 40-46 g. RecrystaUise the crude thiocarbanihde by dissolving it, under reflux, in boiling rectified spirit (filter through a hot water funnel if the solution is not clear), and add hot water until the solution just becomes cloudy and allow to cool. Pure sym.-diphenylthiourea separates in colourless needles, m.p. 154°. 

Upon heating thiocarbanilide with concentrated hydrochloric acid, it is partly converted into phenyl tso-thiocyanate  

A little hydrogen sulphide is evolved in the reaction and triphenylguanidine is formed as a by-product, probably in accordance with the following scheme  

The 2003 ACGIH threshold limit value-time-weighted average (TLV-TWA) for phenol is 5 ppm (19mg/m ) with a notation for skin absorption. 

National Institute for Occupational Safety and Health Criteria for a Recommended Standard... Occupational Exposure to Phenol. DHEW (NIOSH) Pub No 76-1967, pp 23-69. Washington, DC, US Government Printing Office, 1976 

Foxall PJD, Bending MR, Gartland KPR, et al Acute renal failure following accidental cutaneous absorption of phenol Application of NMR urinalysis to monitor the disease process. Hum Toxicol 9 491-496, 1989 

Bruce RM, Santodonato J, Neal MW Summary review of the health effects associated with phenol. Toxicol Ind Health 3 535-568, 1987 

Reacimj.—Dissolve a few ciystals in water, acidify with dilute hydrochloric acid, and add a drop of sodium nitrite solution. A deep biown solution (Bismarck brown) is obtained. See Appendix, p. 279. 

The cli tiicthylaniline is dissolved in the dilute hydiochloiic acid, in n. Ijeaker and cooled in a free/.ing mi.xture. The sodium 

Reactions.—X. Dissolve a few crystals in dilute hydrochloric acid and add a little zinc dust. The solution is decolourised through the formation of dimethyl -phenylenediaiTiinc, (CH,),N.QHjNHo. 

Warm a few of the crystals with yellow ammonium sulphide solution for a few minutes, acidify with hydrochloric acid, und finally add a little feiric chloride. A deep blue colouration Ls produced, due to the formation of methylene blue. 

Dissolve 6 grams of caustic soda in 250 c.c. of water und heat to boiling. Add 5 grams of the hydrochloride of nitroso-dimethylanilinegradually. The free base, which separates out in oily drops, is allorved to dissolve before each fresh addition. The boiling is continued until the dark gieen colour of the liquid 

Also termed phenyl mustard oil or phenyl tliiocarbimide. 

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Dipping solution Dissolve 50 mg 1,2-phenylenediamine in 50 ml 10% ethanolic trichloroacetic acid. 

Unlike 1,2-diaminoethane, 1,2-phenylenediamine does not add to 1-dialky-laminobut-l-en-3-ynes in the presence of sulfuric acid (84DIS). An attempt to carry out the reaction in an aqueous medium under the conditions of hydroxyl-amine addition resulted in the isolation of 4-dialkylaminobut-3-en-2-one (84DIS). 

Quinoxalines are obtained when esters of 2-keto 3-fluoroacid derivatives (86BSF864) and 3,3-dicyano-2-(trifluoromethyl)acrylic acid [91-JFC(51)323] are treated with 1,2-phenylenediamine. 

For the preparation of CoSalophen Y the Co—Y was impregnated by salicy-laldehyde, and 1,2-phenylenediamine in methanol was added slowly to the mixture.107 This was a successful encapsulation of a salen-type complex with larger diamine than the ethylenediamine, a successful preparation of an encaged metal-salen complex by the intrazeolite ligand synthesis method, and a successful intrazeolite synthesis using two different precursor molecules. 

When 2-anisidine, p-acetylaniline, 1,2-phenylenediamine, and 2-trifluro-methylaniline were used, the above procedure gave oifly monosubstituted or A-phenylglycine derivatives. 

A free-radical mechanism has been suggested for the nitrosation of 1,2-phenylenediamine (22) by peroxynitrite PN/CO2. 1,2,3-Benzotriazole (26) was formed as a result of an intramolecular nucleophilic displacement on the diazo hydroxide (25) by the neighbouring amine group. The authors suggest that the mechanism involves an initial H-atom abstraction or one-electron oxidation from (22) by CO3 , followed by the reaction of the product (23) with NO. The inhibitory effects of azide support a free-radical mechanism of the reaction. 

As observed, aromatic hydrocarbons gave products of protonation on dissolution in hydrofluoric acid. Oxidation into aromatic cation-radicals did not take place (Kon and Blois 1958). Trifluoro-acetic acid is able to transform aromatics into cation-radicals. This acid is considered a middle-powered one-electron oxidant (Eberson and Radnor 1991). Its oxidative ability can be enhanced in the presence of lead tetraacetate. This mixture, however, should be used carefully to avoid oxidation deeper than the one-electron removal. Thus, oxidation of 1,2-phenylenediamine by the system Pb(OCOCH3)4 -I- CE3COOH -P CH2CI2 leads to the formation of either primary or secondary cation-radicals. The primary product is the cation radical of initial phenylenediamine, whereas the secondary product is the cation radical of dihydrophenazine (Omelka et al. 2001). Sulfuric acid is also used as an one-electron oxidant, especially for aromatic hydrocarbons. In this case, generation of cation radicals proceeds simultaneously with the hydrocarbon protonation and sulfonation (Weissmann et al. 1957). 

Ligand (233) contains two 1,2-phenylenediamine domains that can be independently oxidized, and this is observed in the complex [(NH3)4Ru(/i-233)Ru(NH3)4] " " which undergoes two, two-electron ligand-oxidation processes further oxidation generates Ru -containing... 

Reaction of 4-benzoyl-3-hydroxy-2(5H)-furanone with 1,2-phenylenediamine results in a low yield of diazepine 251 (Eigure 3 (1991JHC1501)). 

An alternahve method had been reported in the literature [12] to prepare [1,2,4] triazolo[4,3-a]piperazines (Route B, Scheme 5.9) via the condensahon of a chloromethyl oxadiazole with 1,2-phenylenediamine to afford the benzo fused compounds. The reachon condihons reported for this approach were harsh and the yields were low, presumably due to the poor nucleophilicity of 1,2-phenylenedi-amine. However, we felt that the synthesis of 3 could potentially be accomplished under milder reachon condihons because of the enhanced nucleophilicity of... 

As already described, with the exception of iodo, all halogens have proved useful DMGs in the pyridine series for the preparation of potential intermediates and final products related to biologically interesting molecules (Schemes 36, 41-47, 57). As specific applications, the reaction of chloro ketones 524 with ethylene diamine and 1,2-phenylenediamine give, respectively, pyrido[4,3-c]-l, 4-diazepines 525 and pyrido[4,3-6]-1,5-benzodiazepines 523 in good yields (Scheme 160) (87AP704). 

Vasudevan, D., and A. T. Stone, Adsorption of catechols, 2-aminophenols, and 1,2-phenylenediamines at the metal (hydr)oxide-water interface Effects of ring substituents on the adsorption onto Ti02 , Environ. Sci. Technol., 30, 1604-1613 (1996). 

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