Aromatic bicarbonic acids

The statistical copol5miers of polyarylesterketones, involving naphdia-lene cycle in the main ehain, ean be produeed [388] by low-temperature polycondensation of bisphenyloxide, 4,4 - -bis(P-naphtoxy)benzophe-none with chloranhydrides of aromatic bicarbonic acids - terephthaloyl-chloride and isophthaloylchloride (I) in the presence of catalytical system AlCl3/N-methylpirrolydone/ClCH2CH2Cl (copolymers are characterized by improved thermo- and chemical stabiUty), and also by the reaction of hydroquinone with l,4-bis(4,4 -flourobenzoyl)naphthalene (II) in the presence of sodium and potassium carbonates in bisphenylsulfone [389],... 

Takeuchi Hasashi, Kakimoto Masa-Aki., Imai Yoshio. (2002). Novel Method for Synthesizing Aromatic Polyketones from Bis(arylsilanes) and Chlorides of Aromatic Bicarbonic Acids J. Polym. Sci. A, 40(16), 2729-2735. 

If both acidic and basic groups are present, the substance may be amphoteric and therefore soluble in both acid and base. Aromatic aminocarboxylic acids are amphoteric, like aliphatic ones, but they do not exist as zwitterions. They are soluble in both dilute hydrochloric acid and sodium hydroxide, but not in bicarbonate solution. Aminosulfonic acids exist as zwitterions they are soluble in alkali but not in acid. 

Phosphonomycin,—Yet another synthesis of phosphonomycin (22) has appeared (Scheme 6). The phosphonoaldehyde (23) was treated with pentan-3-one and cyclohexylamine to give (24), which was then converted into its oxime. Tosylation of this oxime followed by treatment with bicarbonate caused the molecule to fragment, liberating the dimethyl ester of (22). Disodium phosphonoacetic acid when administered orally or topically to mice infected with Herpes simplex virus will reduce significantly the mortality of mice caused by this virus. JV-Phosphonomethyl-glycine is a promising herbicide. Recent work has shown that it exerts its effect by inhibiting the biosynthesis of aromatic amino-acids. ... 

Aromatic amino acids (e.g., tyrosine) which favorably reduce the retention of polarizable anions at alkaline pH, have a comparatively high elution power. p-Cyanophenol acts in a similar way. When it is added to a carbonate/bicarbonate mixture, a wealth of polarizable anions can be separated at a suitable stationary phase (lonPac AS4A and ASS) and detected via their electrical conductivity. Today, tyrosine as well as p-cyanophenol are only rarely used as eluants, because both acrylate-based and cryptand anion exchangers allow the separation of polarizable and non-polarizable anions in the same run. 

Esterification with an aromatic alcohol may be readily achieved by using an excess of the acid. The latter is readily removed by washing with water and/or treatment with sodium bicarbonate solution, for example ... 

To hydrolyse an ester of a phenol (e.g., phenyl acetate), proceed as above but cool the alkaline reaction mixture and treat it with carbon dioxide until saturated (sohd carbon dioxide may also be used). Whether a solid phenol separates or not, remove it by extraction with ether. Acidify the aqueous bicarbonate solution with dilute sulphuric acid and isolate the acid as detailed for the ester of an alcohol. An alternative method, which is not so time-consuming, may be employed. Cool the alkaline reaction mixture in ice water, and add dilute sulphuric acid with stirring until the solution is acidic to Congo red paper and the acid, if aromatic or otherwise insoluble in the medium, commences to separate as a faint but permanent precipitate. Now add 5 per cent, sodium carbonate solution with vigorous stirring until the solution is alkaline to litmus paper and the precipitate redissolves completely. Remove the phenol by extraction with ether. Acidify the residual aqueous solution and investigate the organic acid as above. 

The crude ketal from the Birch reduction is dissolved in a mixture of 700 ml ethyl acetate, 1260 ml absolute ethanol and 31.5 ml water. To this solution is added 198 ml of 0.01 Mp-toluenesulfonic acid in absolute ethanol. (Methanol cannot be substituted for the ethanol nor can denatured ethanol containing methanol be used. In the presence of methanol, the diethyl ketal forms the mixed methyl ethyl ketal at C-17 and this mixed ketal hydrolyzes at a much slower rate than does the diethyl ketal.) The mixture is stirred at room temperature under nitrogen for 10 min and 56 ml of 10% potassium bicarbonate solution is added to neutralize the toluenesulfonic acid. The organic solvents are removed in a rotary vacuum evaporator and water is added as the organic solvents distill. When all of the organic solvents have been distilled, the granular precipitate of 1,4-dihydroestrone 3- methyl ether is collected on a filter and washed well with cold water. The solid is sucked dry and is dissolved in 800 ml of methyl ethyl ketone. To this solution is added 1600 ml of 1 1 methanol-water mixture and the resulting mixture is cooled in an ice bath for 1 hr. The solid is collected, rinsed with cold methanol-water (1 1), air-dried, and finally dried in a vacuum oven at 60° yield, 71.5 g (81 % based on estrone methyl ether actually carried into the Birch reduction as the ketal) mp 139-141°, reported mp 141-141.5°. The material has an enol ether assay of 99%, a residual aromatics content of 0.6% and a 19-norandrost-5(10)-ene-3,17-dione content of 0.5% (from hydrolysis of the 3-enol ether). It contains less than 0.1 % of 17-ol and only a trace of ketal formed by addition of ethanol to the 3-enol ether. 

A solution of estradiol (38, 15 mg) in methanol-OD (4 ml) and one drop of 10% deuteriosulfuric acid in deuterium oxide is heated under reflux for 5 days. After cooling the reaction mixture is diluted with ether, washed with dilute sodium bicarbonate solution and water, then dried over anhydrous sodium sulfate. Evaporation of the ether gives crystalline 2,4-d2-estradiol (39, 15 mg, 99%), mp 173-175° (ether-hexane), exhibiting 82% isotopic purity and only one aromatic hydrogen by NMR. (For an experimental procedure describing the exchange of aromatic protons under Clemmensen conditions, see section III-D.)... 

The first step involved the reaction of PPO with chlorosulfonic acid according to a literature method (H). The sulfonated PPO was hygroscopic and unstable. We succeeded (12) in converting the sulfonate groups into stable sulfone groups by reacting them with aromatic compounds at elevated temperatures (120 0. The final dark solution was washed with dilute sodium bicarbonate, and the product precipitated in methanol, filtered and dried. 

A careful NMR study by the same group has shown that the 1-azaquinolizinium ion in neutral aqueous solution undergoes hydration to yield (241), but the equilibrium is shifted to the aromatic species (234) if the solution is made 0.1 M in acid (Scheme 118). Bicarbonate causes ring opening to afford j8-(2-pyridylamino)acrolein (242), which can be recyclized in acid. Deuteromethanol also adds to the 1-azaquinolizinium ring, in a transannular manner, and triethylamine converts the resulting salt (243) to 4-methoxy-l-aza-4 7-quinolizine (244). 

Epoxidation of aromatic hydrocarbons is an important method for the preparation of arene oxides. m-Chloroperbenzoic acid (MCPBA) is used in a two-phase system that involves treating the hydrocarbon with a large excess ( 10-fold) of MCPBA in methylene chloride-aqueous sodium bicarbonate at room temperature. The yields are moderate (10-60%). Because the arene oxides are sensitive to acids, the presence of sodium bicarbonate buffer is necessary. A number of K-region (see Section VII for a definition) epoxides like phenanthrene 9,10-oxide (1, 59%), 9,10-dimethylphenanthrene 9,10-oxide (2,40%), 9-phenylphenanthrene 9,10-epoxide (3,50%), pyrene 4,5-oxide (4, 14%), and chrysene 4,5-oxide (5,9%) have been prepared by this method.9... 

Fig (10) The iron complex (80), prepared from methyl abietate (79) is converted to compound (81) utilizing standard organic reactions. It was converted to allylic alcohol (82) by treatment with iodine and potassium bicarbonate. The ketone (83) obtained from (82) undergoes aromatization on bromination and dehydrobromination. Yielding (84) whose transformation to lactone (87) is accomplished following the similar procedure adopted for the conversion of (68) to (74). It is converted to pisiferic acid (1) by treatment with aluminium bromide in... 

The conventional dienone-phenol rearrangements of o-quinol acetates are described above. An alternative mode of restructuring to an aromatic system has been observed, exemplified by the quantitative conversion of the 2,4-dienone (155) on heating at 110 C in acetic acid to the benzylic acetate (156). The related 2,4-dienone (157) rearranges at 70-80 °C in dimethyl sulfoxide-sodium bicarbonate to the... 

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