2- Chloro-4-aminophenol

The present method is the result of a study by Cason, Harman, Goodwin, and Allen.6 7 The sequence of electrolytic reduction followed by oxidation has been used for the preparation of 5-bromotoluquinone,8 5-chlorotoluquinone,9 and 3-chlorotolu-quinone.10 The preparation of an intermediate />-aminophenol from the corresponding aromatic nitro compound by electrolytic reduction is a useful general method.11-18 Chloro-/>-quinone has been prepared by acid dichromate oxidation of chlorohydro-quinone 19-22 or 2-chloro-4-aminophenol.23 24 It has been shown that pure chloro-/>-quinone is obtained only with some difficulty when chlorohydroquinone is used.7... 

An on-line technique coupling preconcentration via a precolumn packed with PGC and LC with a PGC analytical column has been applied to the trace-level determination of some polar and water-soluble organic pollutants from environmental waters.As these analytes are much more retained by the graphite surface than by silica Cig, preconcentration on the PGC precolumn cannot be coupled on-line with a widely used and more efficient Cjg silica analytical columns. In this study, applications were presented for the trace-level determination of 2-chloro-4-aminophenol, chloroanilines, amino-phenols, and cyanuric acid these organic compounds are included in the EC environmental priority pollutant list. The influence of the sample matrix was investigated with drinking and river water samples. 

The filtrate, which smells strongly of toluenesulfonyl chloride, is evaporated to dryness. The gray residue is treated with soda solution, and the solution is shaken out with ether. From the ether extract, a substance crystallizes which has a melting point of 140°C. and which is soluble in hydrochloric acid and sodium hydroxide, but not in soda solution. Ferric chloride gives a red color with the substance in hydrochloric acid solution. The compound contains halogen and can be diazo-tized and coupled with R salt to produce a dye. It is apparently a chloro-aminophenol. 

Uses. (9-Nitrochlorobenzene is used in the synthesis of azo dye intermediates such as o-chloroaniline (Fast YeUow G Base), i9-nitroani1ine (Fast Orange GR Base), o-anisidine (Fast Red BB Base), o-phenetidine, and (9-aminophenol (see Azo dyes). It also is used in corrosion inhibitors, pigments, and agriculture chemicals. -Nitrochlorobenzene is used principally in the production of intermediates for azo and sulfur dyes. Other uses include pharmaceuticals (qv), photochemicals, mbber chemicals (qv), and insecticides (see Insectcontroltechnology). Typical intermediates manufactured from the para isomer are -lutioaruline (Fast Red GC Base), anisidine, -aminophenol, -nitrophenol, -phenylenediamine, 2-chloro-/)-anisidine (Fast Red R Base), 2,4-dinitrochlorobenzene, and l,2-dichloro-4-nitrobenzene. 

Acid YeUow 23 (31), commonly known as Tartraziae, stiU maintains sales of nearly 0.5 million /yr ia the United States. It was first discovered ia 1884 and is made by coupling equimolar quantities of diazotized sulfarulic acid to 3-carboxy-l- -sulfophenyl)-5-pyrazolone. Other monoazopyrazolone dyes of commercial importance iaclude Acid YeUow 17 (32) (sulfarulic acid — l-(2,5-dichloro-4-sulfophenyl)-3-methyl-5-pyrazolone and Acid YeUow 40 [6372-96-9] (33) (Cl 18950) (p-aminophenol l-(4-chloro-2-sulfophenyl)-3-methyl-5-pyrazolone) foUowed by esterification of the phenoUc hydroxy group with -toluenesulfonyl chloride. 

Functional amines, e.g., m-aminophenol, 2-methyl-2-chloro-3-aminophenol, and 4-chloro-3-aminophenol, react with 4-methoxybut-3-en-2-one to yield functional lepidine derivatives 230 (62AG161). 

A collective anaerobic and aerobic treatment by immobilized microorganisms was first shown [66, 67] using calcium-alginate-immobilized co-cultures of a facultative anaerobic strain of Enterobacter cloacae. Reaction actually took place in the middle of the alginate beads. In these experiments, the reduced derivatives were oxidized in the outer parts of the alginate beads by a second aerobic strain (two different Alcaligenes species), which had the ability to oxidize 4-chloro-2-aminophenol. 

Cyclization, 2-mercaptobenzoxazole from o-aminophenol, 30, 57 methyl cyclopropyl ketone from 5-chloro-2-pentanone, 31, 74... 

The conversion of hydrazobenzene into the isomeric benzidine— discovered by the Russian chemist Zinin in the year 1846—is started catalyticaUy by mineral acids and results from the tendency of the molecule to pass into a form possessing less energy, i.e. into a more saturated condition. The reaction is suitably classified with those of which the chief characteristic is that a substituent united to nitrogen exchanges its point of attachment with an H-atom of the nucleus— usually an H-atom in the p-position. To this class belong the conversion of phenylsulphaminic acid into sulphanilic acid (p. 198), of phenyl-hydroxylamine into p-aminophenol (p. 176), and also of acetanilide into p-aminoacetophenone and of N-chloroacetanilide into p-chloro-acetanilide ... 

Bromocyclohexanone, 2392 Butane-2,3-dione dioxime, 1595 f Butyl isocyanate, 1931 Chloroacetamide, 0788 4-Chloro-2-aminophenol, 2303... 

Many other possibilities can be conceived by positioning the aryl halide into another component. Figure 18 shows the synthesis of dibenzoxazepines 90 starting from o-aminophenols and from o-chloro-p-nitrobenzaldehyde 88 [60]. 

Benzo[ 7]benzofuro[2,3-/][l,4]oxazepine 272 is the sole product obtained from chloro aldehyde 271 and o-aminophenol (Scheme 58 (2001JHC383)). 

Amodiaquin Amodiaquin, 4-[(7-chloro-4-quinilyl)amino]-a-diethylmaino-o-cresol (37.1.1.21), is made by reacting 4,7-dichloroquineoline (37.1.1.1) with 4-aminophenol to... 

Chloro-l,2,3-triazole-4-carbonyl chloride (372) condenses with o-aminophenol in ethyl acetate... 

N 19.18%, yellow powder, mp 236°, almost insol in all usual solvents. Ptepd by condensation reaction of 4-chloro-l,3-dinitro-4 aminophenol in ale containing NaAc. No explosive props mentioned Ref 1) Beil 13, 528 2) Not found in CA thru 1971... 

Phenoxazin-3-ones and phenothiazin-3-ones can be prepared by condensation of 2-aminophenols or -thiols with quinones. Alizarin Green G (61), for example, is obtained from (59) and (60). Similarly, 2-aminothiophenols and 6-chloro-2-methoxy-l,4-benzoquinone (62) afford phenothiazin-3-ones (63). 

In a similar way, aniline, the three toluidines, and the aminophenols can be converted into the corresponding chloro-mercuric compounds in about 40 per cent yields. 

Unfortunately, length restrictions did not permit us to consider in detail the tremendous amount of information available on heteroleptic complexes, which are briefly reviewed in Chapter 7. The reviews do not consider a broad group of autocomplexes — derivatives of nitro-, aminophenols, ketoenols, and also chloro-, bromo-, and iodophenols that are stable to hydrolysis and are only formal analogs of alkoxides and phenoxides. 

H2N(02N)2 C4H2. O.C6H,(N02 )2. Lemon-yel ndls(from AcOH or acet), mp 225—6° insol in w or in aq soda soln diff sol in ale, benz, chlf ligroin. Can be prepd by heating 3,5 dinitro-4-aminophenol with ale soln of 4-chloro-l,3 dinitrophenol. Its expl props were not investigated, although it is probably an p- l... 

Chloro-1,4-benzenediamine, 2342 4-Chloro-2,6-diamino-/V-methylaniline, 2818 4-Chloro-2-aminophenol, 2296 4-Chloro-2-methylaniline, 2790... 

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