4- oxybenzoic acid

Oxidation of 7-hydroxy- and 7-aryl-5-oxo-2,3-dihydro-5//-pyrido[l,2,3- f< ]-l,4-benzothiazine-6-carboxylates and 6-carboxamides with 3-chloroper-oxybenzoic acid in CH2CI2 yielded sulfoxides and sulfones, depending on the molar ratio of the substrate and oxidizing agent (00MIP7). A sulfoxide was prepared by the oxidation of ethyl (3S)-3-methyl-10-(2,6-dimethyl-4-pyridyl)-7-oxo-2,3-dihydro-7//-pyrido[l,2,3-<7c]-l,4-benzothiazine-6-carbox-ylate (OOMIPIO). 

It has been prepared synthetically by Ewins in the following manner Meta-oxybenzoic acid is converted with the aid of dimethyl sulphate into m-methoxybenzoic acid, which is then nitrated, and from the nitration products 2-nitro-3-methoxybenzoic acid is separated. This is reduced to 2-amino-3-methoxybenzoic acid which on heating with methyl iodide, yields 2-methylamino-3-methoxybenzoic acid. On warming this with freshly precipitated silver chloride it yields damascenine hydrochloride. 

The oxidation of 3-benzothiepin to its S -oxide 9 (R = H) was unsuccessful with 3-chloroper-oxybenzoic acid or sodium periodate.68 Also, the route which uses the formation of the di-bromosulfuranes 8, known to be sensitive to hydrolysis (vide infra), was ultimately unsuccessful because 8 is only available if the C — C double bonds of the thiepin ring are deactivated towards bromine addition by ester substituents (R = C02Me), concurrently providing the compound with stability towards hydrolysis.65... 

Oxybenzoic Acid, Nitrated Leed Salt (Lead 2,4,6-Trinitro-3-Oxybenzoate, Trinitrometa-oxybenzoate in Fr). H. Ficheroulle and A. Kovache (Ref) prepd and characterized this material... 

A great advance was made by Barth in 1865, who showed that tyrosine was not ethylamidosalicylic acid. As yet salicylic acid had never been obtained from tyrosine, and Barth, in his attempt to prepare this compound from tyrosine by oxidation, by fusion with potash, obtained para-oxybenzoic acid and acetic acid, the decomposition taking place as follows —... 

Tyrosine was now regarded as ethylamidopara-oxybenzoic acid on reduction, therefore, it should yield ethylamine, but instead of this Hufner, in 1868, obtained ammonia, and he supposed tyrosine to be amidophloretic acid. This view was strengthened when Barth in the following year obtained p-oxybenzoic acid from phloretic acid and also from Schmidt and Nasse s base. This here garded as... 

W, 6.S,+,87 +)-6-Methyl-2,tl-dioxatricyclo[6.3.0.01-6 undecan-3-one Typical Procedure using 3-Chloroper-oxybenzoic Acid 26... 

Propionic acid, crotonic acid, benzoic acid, succinic acid, maleic and fumaric acid, phthalic acid, camphoric acid, glycollic acid, lactic acid, malic acid, tartaric acid, the oxybenzoic acids, pyroracemic acid, laevulinic acid, dehydracetic acid, and aceto-acetic acid (or its esters). 

All these substances (with the exception of fumaric and phthalic acid, which, under the experimental conditions, do not absorb nitrogen) take up more or less readily varying quantities of nitrogen. The m-oxybenzoic acid absorbs considerably less easily than its isomers. 

Materials and Processing. Copolyesters of poly(ethylene terephtha-late) (PET) and para-oxybenzoic acid (FOB) were supplied by the Tennessee Eastman Corporation. Past work Indicates the copolyesters form thermotropic liquid crystalline phases at compositions containing more than 30 mole% POB (26,27,28). The composition of the copolyester studied here contains 60 mole% POB. Quiescent liquid crystalline films were made by compression molding the copolyester at 210, 230, 255, and 285 C, and followed by a quench Into Ice water, ambient air, or cooled In the press with the power off. Film thicknesses ranged between 0.05-0.15 mm. Another sa(q>le of the 40/60 PET/POB copolyester was melted at 270 °C In a Mettler hot stage, manually sheared between glass slides, and then ambient air cooled. 

The diazotization of anthranilic acid, a classic route to benzyne, when carried out in the presence of vinyl acetate, vinyl ethers or 1,1-dichloroethylene gives the expected benzocyclobutenes in about 40% yield. Despite the rather moderate yields this method represents a convenient route to multigram quantities of the parent compounds, benzocyclobutenol and benzocyclobutenone. The latter is easily converted to benzocyclobutene-1,2-dione. The diazotization sequence applied to 2-amino-3,6-dimeth-oxybenzoic acid and 1,1-dichloroethylene results in a 80% yield of 3, imethoxycyclobuten-l-one. Trapping of benzynes with other ethylene derivatives, and especially more substituted alkenes, has given generally poorer, variable results. ... 

From o-diazonaphtbalene and salicylic acid. Dyestuffs have also been prepared from salicylsulpbonic acid and diazo-compounds [54]. Meta- and para-oxybenzoic acids [36], as well as oxy-naphthoic acids [55], give colouring-matters with diazo-compounds. 

That resorcin, in addition to a monoaldehyde, yields a dialdehyde, has always been mentioned. From the three oxybenzoic acids are formed two oxyaldehyde adds,... 

Dichloranhydrite terephtaloyl-di(n-oxybenzoat) was synthesized by effect of thionyl chloride on terephtaloyl-di-n-oxybenzoic acid. 

Composition of polyethers whick were got on the basis of different aromatic oligoethers and dichloranhydrites of terephtaloyl-di-n-oxybenzoic acid were confirmed by IR-spectroscopy data, the properties were studied by different physico-chemical methods. 

In comparison to the standard system for epoxidation which uses m-chloroper-oxybenzoic acid as oxidizing agent, the MTO/H202/aromatic Lewis-base system displays several advantages (1) it is safer but equal in price (2) due to the suppression of epoxide ring opening, it is much broader in scope of applications (3) its selectivity is higher (4) it is more reactive, requires less solvent, the product work-up is easier, and the only byproduct formed is water. 

A similar case of a stereoselective radical-induced lactonization is the cyclization of 4-substitut-ed homoallylic xanthates25. The 5-exo cyclization proceeds with high diastereoselectivity. The thionolactone is easily converted to the corresponding lactone by oxidation with 3-chloroper-oxybenzoic acid to give 2,3-disubstituled dihydro-2(3//)-furanones. 

Triazine 2-oxides 3, accompanied by 1,2,3-triazines 1, were obtained by 3-chloroper-oxybenzoic acid oxidation of 2,5-dihydro-1,2,3-triazines 4.249... 

HEXYLENE (592-41-6) Forms explosive mixture with air (flash point — 14°F/—26°C). Violent reaction with oxidizers, bromine, perchlorates, perchromates, peroxyacetic acid, per-oxybenzoic acid. 

A solution of dibenzoyl peroxide (10 g) in toluene (20 ml) is cooled, with stirring, to —5° and then treated during 5 min with a pre-cooled (—2°) solution of sodium (2 g) in 96% ethanol (50 ml). Sodium peroxybenzoate separates at once. To this mixture is added ice-water, in which the sodium peroxybenzoate dissolves. The aqueous peroxybenzoate solution is separated from the toluene in a separatory funnel and washed twice with ether which removes residual toluene and ethyl benzoate. This purified aqueous solution is cooled and treated with a mixture of concentrated sulfuric acid (5 g) and ice-water (60 g), and the per-oxybenzoic acid liberated is shaken into chloroform (60 ml in two portions). The chloroform extracts are united and dried over sodium sulfate they may then be used for oxidations. For preparation of crystalline peroxybenzoic acid the chloroform is evaporated in a stream of dry air at ca. 30 mm and 25-30°. The content of active oxygen is determined by iodometric titration. 

Salicylic acids—Oxybenzoic acids.—Three are known, ortho, meta and para. The Acidum salicylicum (XJ. S.), CsHi(OH)COOH, is the ortho acid (1, 2)—138. It was first obtained from essence of spiraia, which consists largely of salicylic aldehyde, and subsequently from oil of wintergreen gaultheria), which contains methyl salicylate, and also from salicin, a glucosld yielding salicylic aldehyde. It is now obtained from phenol. This is fused, and, while a current of dry COa is passed through it, small portions of jNa are added the sodium salicylate thus formed is dissolved in HaO and decomposed with HCl, when the liberated salicylic acid Is precipitated. 

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