Acetic acid 2,4-dinitrophenyl

Preparation of the sulphones. Dissolve the 2 4-dinitrophenyl-sulphide in the minimum volume of warm glacial acetic acid and add 3 per cent, potassium permanganate solution with shaking as fast as decolourisation occurs. Use a 50 per cent, excess of potassium permanganate if the sulphide tends to precipitate, add more acetic acid. Just decolourise the solution with sulphur dioxide (or with sodium bisulphite or alcohol) and add 2-3 volumes of crushed ice. Filter off the sulphone, dry, and recrystaUise from alcohol. 

N 16.09% crysts (from glac acet acid or benz), mp 173—81°. It was prepd by nitrating diphenylmediane with nitric acid (d 1.53) 5 coned sulfuric acid (Ref 1) and by decarboxylation of ethyl bis(2,4-dinitrophenyl-acetic acid (Ref 2). No expl props are reported... 

Dissolve 340 mg of isobutyl 2,4-dinitrophenyl sulphide (Expt 5.205) in 10 ml of acetic acid, warm to about 50 °C and add dropwise 8 ml of 3 per cent aqueous potassium permanganate solution. Maintain the solution at about 50 °C for 20 minutes, and then pass through the solution a stream of sulphur dioxide to decompose excess potassium permanganate. Add crushed ice to the yellow solution to precipitate the crude sulphone. Filter the precipitate, dry and recrystallise from rectified spirit to give the yellow crystalline product, m.p. 105-106 °C the yield is 190 mg (50%). 

Dinitrobenzenesulphenyl chloride reacts in polar solvents (acetone, 1,2-dichloroethane, acetic acid and dimethylformamide) with alkenes to yield crystalline adducts, the / -chloroalkyl-2,4-dinitrophenyl sulphides, e.g. ... 

Thiols react with l-chloro-2,4-dinitrobenzene in alkaline solution to yield crystalline thioethers (2,4-dinitrophenyl sulphides) (1). These sulphides (1) can be readily oxidised in glacial acetic acid solution by potassium permanganate to the corresponding sulphones (2) the latter exhibit a wide range of melting points and are therefore particularly valuable for the characterisation of thiols. (See also Expt 5.208.)... 

Methyl-4-phenylsydnone is nitrated using nitric acid acetic acid at RT to give the 4-nitrophenyl product (80%), with small amounts (<3%) of ortho and possibly the meta product. The use of mixed acid, or fuming nitric acid, at 0°C forms the 2,4-dinitrophenyl product (60-70%) [62CI(L) 1718]. 

Benzyloxycarbonyl, N-(3,5-dinitrobenzyloxy carbonyl), 9-fluorenylmethoxycarbonyl, benzoyl, acetyl and N-(2,4-dinitrophenyl) derivatized amino acids and profens WAX (weak anion-exchange) type CSP tert. -butylcarbamoylquinine as chiral selector on Hypersil silica gel), 3 pm Acetonitrile-methanol (80 20)+400 mM acetic acid+4 mM triethylamine 335 mm x 100 pm i.d. 250 mm effective length, chiral separation... 

When l-(2,4-dinitrophenyl)pyrazole is heated with aqueous alkali, the C—N link is cleaved by a nucleophilic displacement with the formation of pyrazole and the sodium salt of 2,4-dinitrophenol.718 The carbon-nitrogen link is also cleaved readily when more than one pyrazolyl group is joined via nitrogen to the same carbon atom. Thus tri-l-pyrazolylmethane (78) on heating with aqueous acetic acid decomposes to pyrazole and 1-formylpyrazole.719... 

An approach to nitro-substituted l,3-benzodithiole-2-thiones (325) is based on the reaction of l-chloro-2,6-dinitrobenzenes (323) with sodium f-butyl trithiocarbonate which yields dinitrophenyl f-butyl trithiocarbonates (324). The latter cyclize on heating in acetic acid with formation of nitro-l,3-benzodithiole-2-thiones (325) (80JOC4041). 

Dinitrophenyl ester of A,yV-dimcthyldithiocarbamic add is reduced with iron powder in glacial acetic acid with the formation of 5-nitrobenzothiazolethione-2 [407, 408] (Scheme 2.108), which is extensively used in coordinating chemistry [594-597],... 

The incorporation of [2-14C]pyruvate and [l-14C]acetate into sugars 17 and 18 was investigated.27 Oxidation of the methyl glycosides of sugar 17 with periodate yielded acetaldehyde from the 1-hydroxyethyl branch. The acetaldehyde (2,4-dinitrophenyl)hydrazone was further oxidized by Kuhn-Roth oxidation to acetic acid, which was degraded by the Schmidt reaction to methylamine and carbon dioxide. Periodate oxidation of the methyl glycosides of sugar 18 produced acetic acid from the C-acetyl branch. The acetic acid was isolated, and purified as 1-acetamidonaphthalene. 

Products and reactants, and A-dinitrophenyl-glutamyl-glycine (internal standard) were separated on a Zorbax Q8 column (6.2 mm X 80 mm, 3 un). Solvent A was 0.3 M acetic acid. Solvent B was 50% (v/v) acetonitrile in 0.3 M acetic acid. The gradient, started at the time of sample injection, was increased linearly from 50% solvent B to 100% solvent B over a 10-minute period and held at 100% solvent B for 2 minutes. Return to initial conditions was made in 5 minutes. The column effluent was monitored at 365 nm. 

In the early prototype instrument [1], the columns were fabricated from relatively large-bore PTFE tubing of 4.6 mm inner diameter (i.d.) with PTFE disk inserts having 0.8-mm-diameter holes. These disks were spaced in 3-mm intervals to form 47 locules in each unit. A number of column units were connected in series to provide 5000 locules with a total capacity of 100 mL. The capability of the system was demonstrated with the separation of DNP (dinitrophenyl)-amino acids using a two-phase solvent system composed of chloroform-acetic acid-0.IM HCl at a 2 2 1 volume ratio. In this system, nine DNP-amino acids were resolved within 70 h at about 3000 theoretical plates. 

Oximes of type 4, prepared by nitrosation of 2,6- and 2,4-dinitrophenyl-acetic acid derivatives, cyclize in strong base, e.g., sodium hydride in 1,2-dimethoxyethane, to indoxazene-3-carboxylic acid derivatives, e.g., 5 (R = OMe or NHAr).8-10... 

Bost and his co-workers611 have reported a generally applicable procedure for the preparation of alkyl 2,4-dinitrophenyl sulfones by use of potassium permanganate in glacial acetic acid. 

The decomposition products in irradiated solutions of polymyxin and in their hydrolysates were identified by paper electrophoresis in a pyridine-acetate buffer solution (pH 5.7, 1200 volts) and by paper chromatography using the systems butyl alcohol-acetic acid-water (4 1 5) and phenol-ethyl alcohol-water (2 1 1, in an NH3 atmosphere). For detection, ninhydrin and 2,4-dinitrophenyl hydrazine were used. 

Z-Pelletierine has been shown to possess the It configuration (II) at the asymmetric center (14). (— )-Sedridine, known to have the B configuration at the asymmetric center in the piperidine ring, furnishes iZ-( — )-pelletierine when oxidized with chromic acid in aqueous acetic acid. (-I-)-Sedridine gives 5-(- -)-pelletierine on oxidation (14). The method of resolution of racemic pelletierine through salts with the 6,6 -dinitrophenyl-2,2 -dicarboxylic acids (15) has been improved (16). 

From the alkyl 2,4-dinitrophenyl thioether (prepared from the alkyl halide as above) in glacial acetic acid, with aqueous potassium permanganate. 

Peracetic acid rates measured in acetic acid at 25°C. 2,4-Dinitrophenyl diazonium ion rates as in ref. 176. 

---