Photographic development

Prepared by reduction of 4-nitrophenol or 4-nitrosophenoi. Can be diazotized and used as a first component in azo-dyes. Chief outlet is for sulphur dyes in which it is fused with sodium polysulphides. L/sed as a photographic developer. 

M.p. 190-192 C. The enolic form of 3-oxo-L-gulofuranolactone. It can be prepared by synthesis from glucose, or extracted from plant sources such as rose hips, blackcurrants or citrus fruits. Easily oxidized. It is essential for the formation of collagen and intercellular material, bone and teeth, and for the healing of wounds. It is used in the treatment of scurvy. Man is one of the few mammals unable to manufacture ascorbic acid in his liver. Used as a photographic developing agent in alkaline solution. 

Obtained by fusing o-t nzenedisulphonic acid with NaOH. It is used as a photographic developer, for preparation of dyes and pharmaceuticals, and as an antioxidant. 

CgHeNj. Brown-yellow crystals m.p. 103-104 C, b.p. 256 258°C. Its solutions reduce Ag ions and it is used as a photographic developer. It is also used as a dye-precursor, for the synthesis of phenazine derivatives and for characterizing inter alia) a-diketones. 

It is used for hair dyeing, as a rubber accelerator and as a photographic developer. Derivatives are extensively used as developers in colour photography. 

CgH,oN20. Colourless crystalline solid, m.p. 121 °C. Made by reacting phenylhydrazine with ethyl acrylate to obtain the hydrazide which cyclizes to the product. Its major commercial importance is as a photographic developing agent, being used particularly in conjunction with hydroquinone. 

The total hydioquinone capacity is estimated to be 45,000 50,000 i/yt demand for 1992 was around 40,000 i/yt. Hydioquinone is used in a broad range of apphcations such as photographic developers, polymeri2ation inhibitors, mbber antioxidants, food antioxidants, synthesis intermediates, and water treatment. 

The dibydrochloride salt is used as a photographic developer. It also is employed as an intermediate in the manufacture of fur dyes, in hair dyeing, as a reagent in testing for ammonia and formaldehyde, and as an oxygen scavenger in water to prevent boiler corrosion (173). 

Its chief use is as a component in photographic developers. Because the free compound is unstable in air and light, it is usually marketed as the sulfate salt [55-55-0] Metol, mp 260°C (dec.). It also finds appHcation as an intermediate for fur and hair dyes and, under certain circumstances, as a corrosion inhibitor for steel. Prolonged exposure to 4-(/V-methy1amino)pheno1 has been associated with the development of dermatitis and allergies. 

The close electrochemical relationship of the simple quinones, (2) and (3), with hydroquinone (1,4-benzenediol) (4) and catechol (1,2-benzenediol) (5), respectively, has proven useful in ways extending beyond their offering an attractive synthetic route. Photographic developers and dye syntheses often involve (4) or its derivatives (10). Biochemists have found much interest in the interaction of mercaptans and amino acids with various compounds related to (3). The reversible redox couple formed in many such examples and the frequendy observed quinonoid chemistry make it difficult to avoid a discussion of the aromatic reduction products of quinones (see Hydroquinone, resorcinol, and catechol). 

Phenidone, l-phenyl-3-pyrazolidone (738) (B-76M140404), has been used as a nonstaining, high contrast photographic developer. New optical brighteners containing 2-pyrazolines (739) and pyrazoles (740) have been synthesized recently and their properties and applications reviewed (75AG(E)66s). 

The oxidizing properties of MnOy are utilized in the oxidation of aniline for the preparation of hydroquinone which is important as a photographic developer and also in the production of dyes and paints. 

Plates. Ilford RAO or Kodak V-F. Charge holder in darkroom. Photographic developer. Ilford ID-2 or equivalent. Dilute 1 volume with 2 volumes of water. 

Catalytic Phenomena Related to Photographic Development T. H.James... 

Titanium, tetrakis(trimethysilyl)oxy-, 3, 334 Titanium, tetranitrato-stereochemistry, 1,94 Titanium, triaquabis(oxalato)-structure, I, 78 Titanium, tris(acetylacetone)-structurc, 1,65 Titanium alkoxides oligomeric structure, 2,346 synthesis ammonia, 2, 338 Titanium chloride photographic developer, 6,99 Titanium complexes acetylacetone dinuclear, 2, 372 alkyl... 

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