Carboxylic acid from diols

Polyester Polyols. Polyester polyols are based on saturated aliphatic or aromatic carboxylic acids and diols oi mixtures of diols. The carboxylic add of choice is adipic acid because of its favorable cost/performance ratio. For elastomers, linear polyester polyols of ca 2000 mol wt are preferred. Branched polyester polyols, formulated from higher functional glycols, are used for foam and coatings applications. Phthalates and terephthalates are also used. 

Cobalt(II) salts are effective catalysts for the oxidation of 1,2-glycols with molecular oxygen in aprotic polar solvents such as pyridine, 4-cyanopyridine, benzonitrile, DMF, anisole, chlorobenzene and sulfolane. Water, primary alcohols, fatty acids and nitrobenzene are not suitable as solvents. Aldehydic products are further oxidized under the reaction conditions. Thus, the oxidative fission of rram-cyclo-hexane-l,2-diol gives a mixture of aldehydes and acids. However, the method is of value in the preparation of carboxylic acids from vicinal diols on an industrial scale for example, decane-1,2-diol is cleaved by oxygen, catalyzed by cobalt(II) laurate, to produce nonanoic acid in 70% yield. ... 

N03)j, a newcomer to the arena of oxidants, is useful for the acetoxylation of aromatic side chains in benzylic positions [415, 416] and for the oxidation of methylene or methyl groups that are adjacent to aromatic rings to carbonyl groups [238, 415, 417]. The reagent also oxidizes alcohols to aldehydes [418, 419, 420, 421] and phenols to quinones [422, 423], cleaves vicinal diols to ketones and a-hydroxy ketones to acids [424, 425], and converts diaryl sulfides into sulfoxides [426]. A specialty of ammonium cerium nitrate is the oxidative recovery of carbonyl compounds from their oximes and semicarbazones [422, 427] and of carboxylic acids from their hydrazides [428] under mild conditions. 

Manganese dioxide/potassium hydroxide Carboxylic acids from alcohols Preferential oxidation Lactols from diols... 

Lanthanides are also claimed (23) to perform as catalysts or cocatalysts for polycondensation by direct esterification of carboxylic acids with diols, for production of coating compositions from air-crosslinkable water soluble polymers, as well as for polymerization of epoxides and isocyanates. 

Lewis acidic boron in much the same way that hydrated Lewis acidic metal ions exchange bound water. A pertinent comparison can be found with the ionisation of Zn in water, the reaction Zn OH2 - Zn-OH + having a p.Ka of 8.8. Boronic acids have been reported to rapidly and reversibly " interact with dicarboxylic acids,a-hydroxy carboxylic acids and diols to form esters in aqueous media.The most common interaction is with 1,2 and 1,3 diols to form five- and six-membered rings, respectively. From experimental observations, it is well known that the kinetics of this interconversion are fastest in aqueous basic media where the boron is present in its tetrahedral anionic form. Typically, differences in rate of 10" are observed between boron in its trigonal and tetrahedral forms. ... 

A variant of the Williamson ether synthesis uses thallium alkoxides. The higher reactivity of these can be of advantage in the synthesis of ethers from diols, triols and hydroxy carboxylic acids, as well as from secondary and tertiary alcohols on the other hand however thallium compounds are highly toxic. 

The production of alcohols by the catalytic hydrogenation of carboxylic acids in gas-liquid-particle operation has been described. The process may be based on fixed-bed or on slurry-bed operation. It may be used, for example, for the production of hexane-1,6-diol by the reduction of an aqueous solution of adipic acid, and for the production of a mixture of hexane-1,6-diol, pentane-1,5-diol, and butane-1,4-diol by the reduction of a reaction mixture resulting from cyclohexane oxidation (CIO). 

From the preceding discussion, it is easily understood that direct polyesterifications between dicarboxylic acids and aliphatic diols (Scheme 2.8, R3 = H) and polymerizations involving aliphatic or aromatic esters, acids, and alcohols (Scheme 2.8, R3 = alkyl group, and Scheme 2.9, R3 = H) are rather slow at room temperature. These reactions must be carried out in the melt at high temperature in the presence of catalysts, usually metal salts, metal oxides, or metal alkoxides. Vacuum is generally applied during the last steps of the reaction in order to eliminate the last traces of reaction by-product (water or low-molar-mass alcohol, diol, or carboxylic acid such as acetic acid) and to shift the reaction toward the... 

A dispersant that can be used in drilling fluids, spacer fluids, cement slurries, completion fluids, and mixtures of drilling fluids and cement slurries controls the rheologic properties of and enhances the filtrate control in these fluids. The dispersant consists of polymers derived from monomeric residues, including low-molecular-weight olefins that may be sulfonated or phosphonated, unsaturated dicarboxylic acids, ethylenically unsaturated anhydrides, unsaturated aliphatic monocarboxylic acids, vinyl alcohols and diols, and sulfonated or phosphonated styrene. The sulfonic acid, phosphonic acid, and carboxylic acid groups on the polymers may be present in neutralized form as alkali metal or ammonium salts [192,193]. 

The addition of Grignard reagents to aldehydes, ketones, and esters is the basis for the synthesis of a wide variety of alcohols, and several examples are given in Scheme 7.3. Primary alcohols can be made from formaldehyde (Entry 1) or, with addition of two carbons, from ethylene oxide (Entry 2). Secondary alcohols are obtained from aldehydes (Entries 3 to 6) or formate esters (Entry 7). Tertiary alcohols can be made from esters (Entries 8 and 9) or ketones (Entry 10). Lactones give diols (Entry 11). Aldehydes can be prepared from trialkyl orthoformate esters (Entries 12 and 13). Ketones can be made from nitriles (Entries 14 and 15), pyridine-2-thiol esters (Entry 16), N-methoxy-A-methyl carboxamides (Entries 17 and 18), or anhydrides (Entry 19). Carboxylic acids are available by reaction with C02 (Entries 20 to 22). Amines can be prepared from imines (Entry 23). Two-step procedures that involve formation and dehydration of alcohols provide routes to certain alkenes (Entries 24 and 25). 

PLLA-fr-PCL) multiblock copolymers were prepared from the coupling reaction between the bischloroformates of carboxylated PLLA with diol-terminated PCL in the presence of pyridine [140]. LLA was polymerized with SnOCt2 and 1,6-hexanediol followed by the reaction with succinic anhydride to provide the dicarboxylated PLLA. The carboxyl end groups were subsequently transformed to acid chloride groups by the reaction with thionyl chloride (Scheme 65). As expected, the molecular weight distributions were broad for all samples (1.84 < Mw/Mn < 3.17). 

The 1,4-diacetoxylation was also extended to the use of other acyl groups than acetyl. Thus, an unsymmetrical 1,4-acetoxy-trifluoroacetoxylation of 1,3-dienes was developed by the use of added trifluoroacetic acid to the acetic acid used as the solvent330. With the use of acetone as the solvent with an added carboxylic acid a general diacyloxylation was obtained and, for example, the 1,4-dibenzoates of 2-cycloalkene-l,4-diols were prepared directly from the corresponding l,3-cycloalkadienes33d. 

Primary and secondary alcohols are oxidized slowly at low temperatures by benzyltriethylammonium permanganate in dichloromethane primary alcohols produce methylene esters (60-70%), resulting from reaction of the initially formed carboxylate anion with the solvent, with minor amounts of the chloromethyl esters and the carboxylic acids. Secondary alcohols are oxidized (75-95%) to ketones [34] the yields compare favourably with those obtained using potassium permanganate on a solid support. 1,5-Diols are oxidized by potassium permanganate under phase-transfer catalytic conditions to yield 8,8-disubstituted-8-valerolactones [35] (Scheme 10.1). 

An application of industrial importance of Lewis acidic metal salts is the condensation of carboxylic diacids and diols to give polyesters. This is an acid catalysed reaction that in the laboratory is usually catalysed by protic acids. For this industrial application salts of manganese, nickel, or cobalt and the like are used. From a chemical point of view this chemistry may not be very exciting or complicated, the large scale on which it is being carried out makes it to an important industrial reaction [29],... 

The key to a controlled molecular weight build-up, which leads to the control of product properties such as glass transition temperature and melt viscosity, is the use of a molar excess of diisopropanolamine as a chain stopper. Thus, as a first step in the synthesis process, the cyclic anhydride is dosed slowly to an excess of amine to accommodate the exothermic reaction and prevent unwanted side reactions such as double acylation of diisopropanolamine. HPLC analysis has shown that the reaction mixture after the exothermic reaction is quite complex. Although the main component is the expected acid-diol, unreacted amine and amine salts are still present and small oligomers already formed. In the absence of any catalyst, a further increase of reaction temperature to 140-180°C leads to a rapid polycondensation. The expected amount of water is distilled (under vacuum, if required) from the hot polymer melt in approximately 2-6 h depending on the anhydride used. At the end of the synthesis the concentration of carboxylic acid groups value reaches the desired low level. 

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