Stilbene sulfonates

So-called optical bleaches, such asBlankophor BA, a substituted amino stilbene sulfonic acid, like auramine O will show enhanced fluorescence in viscous media or when bound to polymers. The strong blue emission tends to give the dyed fabric, especially when viewed under sunlight illumination, an apparent whiteness to the fabric. This stilbene derivative is... 

Gascowhitener. [Gaston] Stilbene sulfonates cotton and polyester qptical whiteners. 

Isothiocyanate derivatives of stilbene sulfonates have been utilized with marked success as affinity labels for an anion transport protein of the erythrocyte membrane by Rothstein and his associates, - and glucosyl isothiocyanate has been employed to label a glucose transport protein of the human erythrocyte membrane. Both proteins fall in the 90,000-100,000 dalton range (band 3 in the terminology of Fairbanks et oZ. ). In both cases, transport has been reconstituted using phospholipid vesicles and a band 3 preparation - after aflBnity labeling with the appropriate isothiocyanate had provided preliminary evidence that this protein class might be involved in transport. 

Stilben-4-yl)naphthotriazoles (2) are prepared by diazotization of 4-amino-stilbene-2-sulfonic acid or 4-amino-2-cyano-4 -chlorostilbene, coupling with an ortho-coupling naphthylamine derivative, and finally, oxidation to the triazole. 

Condensation dyes from 4-nitrotoluene-2-sulfonic acid are the most important of the stilbene dyes. Direct YeUow 11 (Cl 40000), discovered in 1883 and commonly known as Sun YeUow [1325-37-7] is widely used in the paper industry (2,4). 

Miscellaneous Dyes. Other classes of dyes that stiU have some importance are the stilbene dyes and the forma2an dyes. Stilbene ( es are in most cases mixtures of dyes of indeterminate constitution that are formed from the condensation of sulfonated nitroaromatic compounds ia aqueous caustic alkah either alone or with other aromatic compounds, typically arylarnines (5). The sulfonated nitrostilbene [128-42-7] (79) is the most important nitroaromatic, and the aminoa2oben2enes are the most important arylarnines. Cl Direct Orange 34 [2222-37-6] (Cl 40215-40220), the condensation product(s) of (79) and the aminoa2oben2ene [104-23-4] (80), is a typical stilbene dye. 

Electrochemical reduction of 2,3-diphenylthiirene 1-oxide yields acetylene (80%) and benzil (10%). Electrolysis of 2,3-diphenylthiirene 1,1-dioxide in DMF gives trans-stilbene (30%) but in the presence of acetic acid, 1,2-diphenylvinylmethyl sulfone (27%) is obtained in addition to the stilbene (40%) (81CC120). 

Remarkable solvent effects on the selective bond cleavage are observed in the reductive elimination of cis-stilbene episulfone by complex metal hydrides. When diethyl ether or [bis(2-methoxyethyl)]ether is used as the solvent, dibenzyl sulfone is formed along with cis-stilbene. However, no dibenzyl sulfone is produced when cis-stilbene episulfone is treated with lithium aluminum hydride in tetrahydrofuran at room temperature (equation 42). Elimination of phenylsulfonyl group by tri-n-butyltin hydride proceeds by a radical chain mechanism (equations 43 and 44). 

Wahrend (2-Hydroxy-2-phenyl-athyl)-phenyl-sulfon in Gegenwart von Protonen-Do-natoren zu Stilben gespalten wird (s.S. 633), erhalt man bei Abwesenheit der Donatoren unter C—C-Spaltung 7,2-Diphenyl-glykol und Athyl-phenyl-sulfon (s.S. 633). 

Finally, an electrochemical reduction of bis-a-bromobenzyl sulfone to stilbene and a spectacular, so-called bis-homoconjugative, version of the Ramberg-Backlund reaction, which converts the a-chlorosulfone 100 into the bridged cyclooctatriene derivative 101 (equation 63) , have also been published. 

The procedure described is essentially that of Ballard and Dehn.1 Stilbene has also been prepared by reduction of desoxy-benzoin,20 benzaldehyde,23 and benzil 2o-2c by dehydrogenation of ethyl benzene,30 toluene,30- 33- 3, and bibenzyl 33-3alkaline reduction of phenylnitromethane,40 phenylnitroacetonitrile,40 and desoxybenzoin 43 by distillation of benzyl sulfone,50 benzyl sulfide,60-63 calcium cinnamate,5 cinnamic acid,5d phenyl cinna-mate,6e-6/ and diphenyl fumarate ie by dehydrohalogenation of a,a -dichlorobibenzyl60 and benzyl chloride 63 by dehalogenation of a,a,c/,a -tetrachlorobibenzyl70 and benzal chloride 73 by the coupling of cinnamic acid and phenyldiazonium chloride 8 by de-... 

Stilbenes, photocyclization of, 30, 1 StiUe reaction, 50, 1 Stobbe condensation, 6, 1 Substitution reactions using organocopper reagents, 22, 2 41, 2 Sugars, synthesis by glycosylation with sulfoxides and sulfinates, 64, 2 Sulfide reduction of nitroarenes, 20, 4 Sulfonation of aromatic hydrocarbons and aryl halides, 3, 4 Swem oxidation, 39, 3 53, 1... 

Amm picrate, DATNB or DATB (1,3-Di-a mino-2,4,6-triaminobenzene) DIP AM (Dipicramid), EL-511 (Hexanitrodiphenyl Sulfone or Dipicryl Sulfone) HNDPhA or HNDPA j(Hexanitrodiphenylamine) Cyclo-tetraethylenetetranitramine HNOxn (Hexa-nitrooxanilide) HNS (or HNStb)(Hexanitro-stilbene) KDNBF (Potassium Dinitro-benzofuroxan) LA (Lead Azide) NGu (Nitroguanidine) NONA (Nona nitroter-... 

Ultraviolet irradiation of the methiodide or hydrochloride of 2-styryl-pyridine (XCIII) in the solid state results in transformation of the trans-isomers to the corresponding dimers (XCVa, b) on the other hand irradiation in benzene solution gives both isomerization and dimerization.309 Dimer (XCVa) was produced in low yield on irradiation of XCIII in the powdered form in the presence of air.308 This is in contrast to the reported stability of XCIII toward photodimerization.109 Similar dimerizations have been reported in the case of 2,4-dichloro-3-cyano-6-styrylpyridine,164 2-styrylquinaldine (XCV) and frans-4,4 -diguanyl-stilbene bis(2-hydroxyethane sulfonate) (stilbamidine) (XCIV).82,83... 

The largest proportion (80%) of FBA systems is based on stilbene (88) which itself absorbs at 324 nm. The parent molecule is usually substituted in the 4-position or disub-stituted in the 4,4 -positions. The introduction of sulfonic acid groups into the stilbene skeleton confers water solubility and hence affinity for hydrophilic fibres such as cotton. Products for use on hydrophobic substrates such as polyester require characteristics similar to those of disperse dyes. 

An early example of a monosubstituted stilbene was introduced by Geigy as Tinopal RBS (89) and used for cotton and polyamide (nylon). Conversion of the sulfonic acid group into A-ethylsulfonamide, via the sulfonyl chloride, yields an FBA for polyester and plastics (55USP2713057). The triazole ring is formed by diazotization of the 4-aminostilbene followed by coupling with 2-naphthylamine and oxidation with ammoniacal copper(II) sulfate, occasionally in pyridine (21CB2191). 

In 1964 it was shown by Becker8 that the condensation of phenyl p-tolyl sulfone to p-phenylsulfonyl stilbene (5) proceeded more readily and in improved yield when the reaction was carried out using benzal-aniline rather than benzaldehyde.9 This original observation was... 

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