2-naphthalenesulfonic acid, 6-Amino

Beilstein Handbook Reference) 5-Amino-2-naphthalenesulfonic acid 5-Amino-naphthalene-2-sulphonic acid 1-Amlno-6-sulfo-naphthalene 1-Amino-6-naphthalenesulfonic acid BRN 1819887 1,6-Qeve s acid Cleve s p-acid Oeve s acid-1,6 Cleve s acid, mixed EINECS 204-351-2 Kyselina 1-naftylamin-6-suifonova Kyselina cleve 2-Naphthalenesulfonic acid, 5-amino- 1-Naphthylamine-6-sulfonic acid 5-Naphthylamine-2-sulfonic acid NSC 31506. Intermediate in synthesis of dyestuffs. Solid slightly soluble in 1000 parts H2O (0.1 g/100 ml), insoluble in EtOH, EI2O. 

Amino-2-naphthalenesulfonic acid... - 8 Amino 2-naphthalenesulfonic acid... A-00266 - A-00270... 

EDANS = 5-[(2-aminoethyl)amino]naphthalenesulfonic acid DABCYL = 4- [4-(dimethylamino)phenyl]azo benzoic acid... 

Monoazo dyes with heterocyclic coupling components, such as pyrazolone or pyridone, are yellow to greenish yellow. Other suitable coupling components include aniline and naphthylamine derivatives. Substituted anilines or amino-naphthalenesulfonic acids are employed as diazo components. Examples are C.I. Reactive Yellow4, C.I. Reactive Yellow 17 (see Section 3.1.5). 

In the naphthol series direct sulfonation is usually restricted to / -naphthols, since a-naphtholsulfonic acids are generally obtained in other ways, such as from naphthalene-di- and -tri-sulfonic acids in an alkali meii or from 1-amino-naphthalenesulfonic acids by the Bucherer reaction. 

Another example of manufacture in this series is the sulfonation of an aminonaphthalenesulfonic acid, followed by selected desulfonation, to make 6-amino-l,3-naphthalenedisulfonic acid (21). Thus, 2-amino-l-naphthalenesulfonic acid made by amination of 2-hydroxy-1-naphthalenesulfonic acid is added to 20 wt % oleum at ca 35°C. At this temperature, 65 wt % oleum is added and the charge is stirred for 2 h, is then slowly heated to 100°C and is maintained for 12 h to produce 6-amino-l,3,5-naphthalenetrisulfonic acid. The mass is diluted with water and maintained for 3 h at 105°C to remove the sulfo group adjacent to the amino group. After cooling to ca 20°C and filtration, 6-amino-l,3-naphthalenedisulfonic acid is obtained in 80% yield (55). 

The manufacture of 4-hydroxy-6-amino-2-naphthalenesulfonic acid in ca 85% of the theoretical yield has been described (76). 

Manufacture of 3-hydroxy-4-amino-l-naphthalenesulfonic acid involves the nitrosation of 2-naphthalenol, bisulfite addition, and reduction of the nitroso to the amino group by sulfur dioxide generated in situ (47). 3-Hydroxy-4-amino-l-naphthalenesulfonic acid is obtained in 80% yield. 

By the alkaline hydrolysis of the sultone formed on boiling an aqueous solution of the diazonium salt of S-amino-l-naphthalenesulfonic acid or its appropriate derivatives. 

Sodium Bisulfite. Sodium bisulfite [7631-90-5] NaHSO, is occasionally used to perform simultaneous reduction of a nitro group to an amine and the addition of a sulfonic acid group. For example, 4-amino-3-hydroxyl-l-naphthalenesulfonic acid [116-63-2] C qH NO S, is manufactured from 2-naphthol in a process which uses sodium bisulfite (59). The process involves nitrosation of 2-naphthol in aqueous medium, followed by addition of sodium bisulfite and acidification with sulfuric acid. 

Acid Brown 14 (27) (2 mol of naphthionic acid, ie, 4-amino-1-naphthalenesulfonic acid 1 mol resorcinol) and Acid Black 1 (28). Two other azo acid blacks. Acid Black 52 (43) and Acid Black 63 (44) are both metallized with chromium. 

Fig. 5. Direct red dyes, (a) Direct Red 81 described ia text (68) (b) Direct Red 2 (o-toLidiae coupled to two moles of naphthionic acid) (69) (c) Direct Red 23 (aniline coupled to 6,6 -ureylenebis-l-naplitliol-3-sulfonic acid with a second coupling with j aminoacetanilide) (70) and Direct Red 80 (2 mol 6-amino-3,4 -azobenzenedisulfonic acid coupled twice to 6,6 -ureylenebis-l-naphthol-3-sulfonic acid) (73). Direct Red 24 (4-aniino-y -toluenesulfonic acid coupled under acidic conditions to 6,6 -ureylenebis-l-naphthol-3-sulfonic acid followed by an alkaline coupling of o-anisidine) (71) (d) Direct Red 72 (Broenner s acid, ie, 6-artiino-2-naphthalenesulfonic acid coupled under acidic conditions to 6,6 -ureylenebis-l-naphthol-3-sulfonic acid followed by an...

FD C Red No. 40. This monoa2o dye (5) is manufactured by coupling dia2oti2ed 5-amino-4-methoxy-2-toluenesulfonic with 6-hydroxy-2-naphtha-lenesulfonic acid. FD C Red No. 40 is also known as Allura Red or Cl Food Red 17. Its chemical identity is principally the disodium salt of 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl)a2o]-2-naphthalenesulfonic acid, which has the formula C gH 4N20gS2Na2, and mol wt 496.43. 

Interesting regioselectivities have been known for more than 100 years for azo coupling reactions with aminonaphthol derivatives such as 6-amino-4-hydroxy-2-naphthalenesulfonic acid (12.136, y-acid), 7-amino-4-hydroxy-2-naphthalenesulf-onic acid (J-acid), and 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid (H-acid). They give two types of isomeric azo compounds depending on the pH-value of the... 

Extrinsic fluorescence is used whenever the natural fluorescence of a macromolecule is inadequate for accurate fluorescence measurement. In this case, one can attach a fluorescent reporter group by using the reactive isocyanate or isothiocyanate derivatives of fluorescein or rhodamine, two intensely fluorescent molecules. One can covalently also label a protein s a- and e-amino groups with dansyl chloride (/.e., A,A-dimethylaminonaphtha-lenesulfonyl chloride). Another useful reagent is 8-ani-lino-l-naphthalenesulfonic acid (abbreviated ANS). This compound is bound noncovalently by hydrophobic interactions in aqueous solutions, ANS is only very fluorescent, but upon binding within an apolar environment, the quantum yield of ANS becomes about 100 times greater. 

Chemicals and Materials. Boric Acid and Methanol from Riedel-de Haen (Seelze, Germany). All peptides from Sigma (St. Louis, MO). 4-Amino-l-Naphthalenesulfonic acid (A.N.S.A.) from Aldrich (Steinheim, Germany). Sodium Nitrite and Cuprous Bromide, 98%, from Acres (Geel, Belgium) and HBr, 48%, from Fluka (Buchs, Switzerland). Used chemicals as received. (Adapted from Kuijt et al., 2001)... 

Probtem 18.63 Synthesize from naphthalene and any other reagents (a) naphthionic acid (4-amino-l-naphthalenesulfonic acid), (b) 4-amino-l-naphthol, (c) 1,3-dinitronaphthalene, (d) 1,4-diaminonaphthalene, (e) 1,2-dinitronaphthalene. Do not repeat the synthesis of any compound. ... 

Naphthoresorcinol has been prepared by heating l-amino-3-hydroxy-4-naphthalenesulfonic acid or its salt in water or slightly acidic solution2 and by cyclization of ethyl phenylacetylmalo-nate 3 or of ethyl phenylacetoacetate.4 Phenylacetylmalonic ester has been prepared by condensing phenylacetyl chloride and malonic ester in ether with sodium.3... 

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