Anthracene-1,8-disulfonic acid

More extensive studies using somewhat higher wavelengths have been reported by Geacintov et al. (111, 112). These authors used phototendering dyestuffs notably the sodium salt of anthracene 2,7 disulfonic acid as the sensitizer in aqueous solution. For grafting to cellulose acetate and ethyl cellulose 2-methyl anthraquinone which is soluble in organic solvents was used. The mechanism proposed was the removal of a... 

Electrolysis of benzalacetophenone in the presence of C02 gave a-phenylben-zoylpropionic acid 306 Reduction of stilbene in the presence of C02 yielded 92% meso-2,3-diphenylsuccinic acid 307 The reduction of anthracene at -2,3 V in the presence of S02 and 02 yields 9,10-dihydroanthracene-9,10-disulfonic acid 307a) An interesting intramolecular addition was found in the reduction of the thiocyanato steroid 77 to the mercaptoimine 78 308 ... 

Cl channels underhe a wide range of physiological processes including cell volume regulation, intravesicular acidification and the maintenance of electrical excitability in muscle and nerve membranes. Nine types of Cl channels have been identified, and common pharmacological blockers include 4,4 -diisothiocyano-2,2 -stilbene-disulfonate (DIDS), 9-anthracene-carboxylic acid (9-AC) and p-chlorophenoxy-propionic acid (CPP) (Pusch et al, 2006). 

Scheme 26.1 Preparation of organic salts of anthracene-2,6-disulfonic acid (ADS) and various primary amines.

The 2-sulfonic acid as well as disulfonic acid is formed on sulfonation of anthracene.155 Sulfonation of anthraquinone156 and of phenanthrene157 has been examined in more detail the latter affords 2- and 3-phenanthrenesulfonic acid, which can be separated as described by Fieser.158... 

The concept of the multi-component molecular solid covers co-crystals, mixed crystals, salts, clathrates, and complexes. As Yan and Evans have indicated,multi-component systems of luminescent dyes with a variety of co-assembled units offer a more flexible method for tuning the packing-directed luminescent properties of the dye than the formation of polymorphs of the pure material. An example has already been given above (16). ° Another example is the organic salts of anthracene-2,6-disulfonic acid (20) with amines (Scheme 6). ... 

Practically any aromatic hydrocarbon or aryl halide can be sulfonated if the proper conditions are chosen. As the compound becomes more complex, however, the tendency toward the production of by-products and mixtures of isomers is increased. It is usually difficult to prevent polysubstitution of a reactive hydrocarbon. For example, even when phenanthrene is sulfonated incompletely at room temperature, some disulfonic acids are formed. The sulfonation of anthracene follows such a complex course that the 1- and 2-sulfonic acid derivatives are made from the readily available derivatives of anthraquinone. The foUowii sections include comments.on the accessibility of the reaction products of the commonly available hydrocarbons and aryl halides. The examples cited and still others are listed in Tables I-XIII. 

Anthracene (Table XI, p. 188). Anthracene is sulfonated so readily that even at low temperatures and with a mild sulfonating reagent some polysubstitution occurs. It is striking, therefore, that dilution of the reaction mixture with acetic acid (but not with water) decreases the extent of disubstitution, even with the more reactive sulfonating agents, chlorosulfonic acid or oleum. Under these conditions only 20% of the product consists of disulfonic acids the 1-sulfonic acid is formed in 50% yield, the 2-acid in 30% yield. Substitution in the 2-position is favored by high temperatures, but this is not a result of conversion of the 1-acid into the 2-acid (as is probably true in the case of the naphthalenesulfonic... 

Phenanthrene (Table XII, p. 189). Phenanthrene is as readily sul-fonated as anthracene when the reaction is carried out for three hours at 120-125° with concentrated sulfuric acid, more than 40% of the phenanthrene is converted into disulfonic acids. Two monosulfonic acids are isolated under these experimental conditions phenanthrene-2-sulfonic acid (25% yield) and phenanthrene-3-sulfonic acid (27% yield). The same acids are obtained by sulfonating at 100.° for eight hours (2-acid, 7% 3deld 3-acid, 9% yield), and in addition a third acid, phenanthrene-9-sulfonic acid (6% 3deld) is formed. The 9-acid is formed in larger amounts at lower temperatures (14.5% at 20°, twenty days). A fourth monosulfonic acid, the 1-acid, is isolated from the sulfonation reaction conducted at 60° for several days. The 3uelds of the four monosulfonic acids isolated under these conditions are 4% of the 1-acid, 18% of the 2-acid, 19% of the 3-acid, and 13% of the 9-acid. There is no indication that the only other possible monosulfonic acid, the 4-isomer, is ever formed, probably because the 4-position of phenanthrene is particularly hindered. 

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