Chemical Properties
GREY TO DARK BROWN POWDER. 1,5-Naphthalenediamine [2243-62-1]. 1,5-diaminonaphthalene, Alphamin, C10H10N2, Mr 158.2: oxidation of 97 with iron (III) chloride in water produces a blue-violet color. Treatment with boiling aqueous sodium bisulfite followed by addition of alkali gives a mixture of 1-amino-5-hydroxynaphthalene and 1,5-dihydroxynaphthalene. Sulfonation (5 % oleum, 100℃) gives 1,5-diaminonaphthalene2-sulfonic acid, and nitration in acetic acid produces 2,4,6,8-tetranitro-1,5-diaminonaphthalene. Coupling with diazo compounds takes place in the 2-position; reduction of the resulting azo compound with SnCl2– HCl produces 1,2,5- triaminonaphthalene.
Uses
Aromatic amines likely to have high carcinogenic potency. QSARs of aromatic amines.
Uses
1,5-Naphthalenediamineis an important raw material and intermediate used in organic synthesis, pharmaceuticals, agrochemicals and dyestuffs. The reducing properties of 1,5-diaminonaphthalene (1,5-DAN) as a MALDI matrix ( matrix-assisted laser desorption ionization) to amino acid sequencing and disulfide bond mapping of human urotensin II possessing one disulfide bond, and human guanylin possessing two disulfide bonds.
Uses
1,5-naphthalenediamine be used as intermediates for the synthesis of materials.
Production Methods
1-Nitronaphthalene can be nitrated further to give a 40 : 60 mixture of 1,5- and 1,8-dinitronaphthalenes. Similar results are obtained by direct nitration of naphthalene with H2SO4– HNO3 under careful control of temperature over the range 40 – 80℃. Although separation of the isomers by fractional crystallization or solvent extraction is usually carried out at this stage, the mixed isomers can also be reduced and the resulting diamines separated. Reduction of the dinitronaphthalenes is achieved by treatment of a nonaqueous solution with iron or hydrogen in the presence of a catalyst. An alternative process for 1,5-naphthalenediamine involves amination of 1,5-dihydroxynaphthalene with ammonia and ammonium bisulfite. Although less efficient on a stage basis it offers an economical alternative to nitration and reduction if the 1,8-naphthalenediamine is not also required.
Definition
ChEBI: A naphthalenediamine compound having amino substituents in the 1- and 5-positions.
General Description
Colorless to pale purple crystals or lavender powder.
Air & Water Reactions
1,5-Naphthalenediamine is sensitive to prolonged exposure to air. Insoluble in water.
Reactivity Profile
1,5-Naphthalenediamine neutralizes acids in exothermic reactions to form salts plus water. May be incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen may be generated in combination with strong reducing agents, such as hydrides.
Hazard
Questionable carcinogen.
Fire Hazard
Flash point data for 1,5-Naphthalenediamine are not available. 1,5-Naphthalenediamine is probably combustible.
Safety Profile
Suspected carcinogen
with experimental carcinogenic,
neoplastigenic, tumorigenic data.
Experimental reproductive effects. Mutation
data reported. When heated to
decomposition it emits toxic fumes of NOx.
Purification Methods
Recrystallise the amino-naphthalene from boiling H2O, but this is wasteful due to poor solubility. Boil it in chlorobenzene (charcoal), filter hot and cool the filtrate (preferably under N2). This gives colourless crystals. Dry it in a vacuum till free from chlorobenzene (odour), and store it in sealed ampoules under N2 away from light. [Beilstein 13 IV 340.]
