Aromatic carboxylic acid, condensation

In a related reaction, aromatic carboxylic acids were condensed to a-diketones (2 ArCOOH —> ArCOCOAr) on treatment with excess Li in dry THF in the presence of ultrasound. ... 

Sodium cyclopentadienide, 41, 96 Sodium dichromate for oxidation of alkylarenes to aromatic carboxylic acids, 43, 80 Sodium ethoxide for condensation of diethyl oxalate with diethyl succinate, 44, 67... 

A powerful and efficient method for the preparation of poly(ketone)s is the direct polycondensation of dicarboxylic acids with aromatic compounds or of aromatic carboxylic acids using phosphorus pentoxide/methanesulfonic acid (PPMA)16 or polyphosphoric acid (PPA)17 as the condensing agent and solvent. By applying both of these reagents to the synthesis of hexafluoroisopropylidene-unit-containing aromatic poly(ketone)s, various types of poly(ketone)s such as poly(ether ketone) (11), poly(ketone) (12), poly(sulfide ketone) (13), and poly-... 

Oxidation of olefins 9-27 Oxidation of alkynes 9-65 Reductive condensation of aromatic carboxylic acids... 

Reaction XXXIH. (a) Condensation of an Aromatic Carboxylic Acid with Formaldehyde. (Lederer-Manasse).—In the presence of mineral acids formaldehyde condenses to di-phenyl derivatives with aromatic acids in much the same way as with phenols (Reaction XIII.), except that in this case it is in the meta position the condensation takes place. 

Reaction xxklll. (d) Condensation of Aldehydes with the Sodium Salts of certain Adds in the presence of Add Anhydrides (Perkin). (A., 100,126 227, 48 B., 10,68 14,1826 J. C. S., 21, 53 J 1877, 789.) —This is a reaction of very wide application, and one much used in the preparation of unsaturated aromatic carboxylic acids. It consists in heating together—usually to 180°—an aldehyde, the sodium salt of a fatty acid with at least one oc-hydrogen atom, and an acid anhydride. The following reactions then occur —... 

It has been shown that when n-phenylenediamine condenses with aromatic carboxylic acids in a melt at 185-250 °C (or in high boiling point solvents) in the presence of acids such as polyphosphoric... 

Esters (32 4, R = C(=0)-alkyl or -aryl), of which a-epimers were mainly obtained, were more active than the ethers. Sodium artesunate (32 5, R = C(=0)-CH2CH2C00Na), the half succinic acid half-ester of dihydroartemisinin is water-soluble and shows potent antimalarial activity. Therefore, this can be administered intravenously. However it is uncertain whether this derivative is pharmacologically effective because of its sensitivity to hydrolysis. In considering this result new ether derivatives of dihydroartemisinin, which are stable and water soluble derivatives have been prepared [46]. Dihydroartemisinin was condensed with esters of aliphatic or aromatic carboxylic acids with hydroxy groups to produce mainly ethers with the P-configuration. Ethyl 2-( 10-dihydroartemisininoxy) acetate (31 4, R = CH2COOCH2CH3) and methyl... 

Heravi et al. [100] reported that the synthesis of [l,3,4]-thiadiazolo[2,3-c] [l,2,4]-triazin-4-ones were one-pot condensation and cyclization of 4-amino-[l,2,4] triazine-3-thione-5-ones with various aromatic carboxylic acids in the presence of silica-gel/sulfuric acid in solventless condition (Scheme 3.40). 

Soon after the first preparation of vinyl acetate by the reaction of acetic acid with acetylene and its polymerization by Klatte [209] in 1912, methods for its industrial-scale synthesis were developed first in Germany, then in Canada [210]. At the same time, the chemistry was extended to the preparation and polymerization of vinyl esters of other aliphatic and aromatic carboxylic acids. The new polymers found immediate uses in paints, lacquers, and adhesives. Steady improvements in the industrial-scale monomer synthesis, particularly in the discovery of new catalysts for the acetic acid-acetylene condensation and development of a low-cost synthesis route based on ethylene have made vinyl acetate a comparatively inexpensive monomer. Besides the original applications, which still dominate the major uses of poly(vinyl acetate), this polymer finds additional utility as thickeners, plasticizers, textile finishes, plastic and cement additives, paper binders and chewing gum bases, among many others. At the same time, the uses and production of polymers of the higher vinyl esters have not kept pace with that of poly(vinyl acetate), primarily due to their higher cost. Consequently, the current worldwide production of these materials remains low. 

Both organic and inorganic solid acids are used. As organic acids, Bronsted acids such as condensed compounds of /Mira-substituted phenol with formaldehyde,and Lewis acids such as zinc salts of the above compounds and those of aromatic carboxyl acids are used. As inorganic acids, montmorillonite clays such as bentonite, fuller s earth, kaoline, chinaclay, and their chemically modified materials are used. 

This is an example of the Doebner synthesis of quinoline-4-carboxylic acids (cinchoninic acids) the reaction consists in the condensation of an aromatic amine with pyruvic acid and an aldehj de. The mechanism is probably similar to that given for the Doebner-Miller sj nthesis of quinaldiiie (Section V,2), involving the intermediate formation of a dihydroquinoline derivative, which is subsequently dehydrogenated by the Schiff s base derived from the aromatic amine and aldehyde. 

Under basic conditions, the o-nitrotoluene (5) undergoes condensation with ethyl oxalate (2) to provide the a-ketoester 6. After hydrolysis of the ester functional group, the nitro moiety in 7 is then reduced to an amino function, which reacts with the carbonyl group to provide the cyclized intermediate 13. Aromatization of 13 by loss of water gives the indole-2-carboxylic acid (9). 

Hydrazides of vicinal acetylene-substituted derivatives of benzoic and azole carboxylic acids are important intermediate compounds because they can be used for cyclization via both a- and /3-carbon atoms of a multiple bond involving both amine and amide nitrogen atoms (Scheme 131). Besides, the hydrazides of aromatic and heteroaromatic acids are convenient substrates for testing the proposed easy formation of a five-membered ring condensed with a benzene nucleus and the six-membered one condensed with five-membered azoles. 

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

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