Esters synthesis from carboxylic acids

Adducts (6) and (7) from amides and chlorophosphoric acid aiyl esters or dichlorophosphoric acid aryl esters respectively are well known. - The adducts are formed in a 1 1 ratio. They have been applied to the synthesis of mixed anhydrides from diarylphosphoric acids and carboxylic acids, as well as mixed substituted esters of pyrophosphoric acid. The adduct formation between primary or secondary carboxamides and dichlorophosphates has been used to prepare nitriles and isonitriles respectively. The adduct from DMF and phenyldichlorophosphate is a useful reagent for the preparation of carboxylic acid esters from the corresponding acids and alcohols, 3-lactams from imines and carboxylic acids," carboxylic acid anhydrides, carboxylic acid esters and thiol esters. Adducts of amides with ester amides or diamides of chlorophosphoric acid have been studied. ... 

Synthesis of Carboxylic Acid Esters. The preparation of aliphatic carboxylic acid esters from synthesis gas and the corresponding acid is illustrated by the experimental data summarized in Table VI. Here propionic acid is the coreactant (eq. 21) and CO hydrogenation yields substantial quantities of Cx C4 alkyl propionates. Some 14 catalyst combinations of ruthenium with quaternary Group 5B and alkali metal promoters have been considered. The important features of the catalysis are as follows ... 

Dichlorobis(triphenylarsine)platinum(II)-stannous chloride //n-Carboxylic acid esters from a-olefins Synthesis with addition of 1 C-atom... 

Lithium N-isopropylcyclohexylamide Carboxylic acid esters from halides Synthesis with addition of 2 C-atoms Modified malonic ester synthesis... 

Triethylamine sec-butyl chloroformate Modified Arndt-Eistert synthesis Homologous carboxylic acid esters from carboxylic acids... 

Synthesis of carboxylic acid esters from a,/ -ethylenecarboxylic acid esters... 

A soln. of bromine in methylene chloride added dropwise at ca. 5° to a vigorously stirred mixture of the startg. m., aq. 8%-NaHCOg, hexamethylphosphoramide, and methylene chloride, and stirred 1 hr. at 0-5° product. Y 93%. F. e., also carboxylic acid esters from 2 alcohol molecules (cf. Synth. Meth. 9, 363), and with chlorine in the presence of NaH2P04, s. M. A. Neirabeyeh et al., Synthesis 1976, 811 0x0 compds. from alcohols with triethylenediamine-2 Brg complex s. L. K. Blair, J. Baldwin, and W. C. Smith, Jr., J. Org. Chem. 42, 1816 (1977). 

Kiliani-Fischer synthesis— Labeled carbohydrate derivatives s. 11, 732 Carboxylic acid esters from aldehydes GHO GH2GOOR... 

Palladium-carbon Carboxylic acid esters from 2,3-dialkoxy-2,3-dihydrofurans Synthesis with addition of 3 C-atoms... 

Polymeric phosphonium salt-bound carboxylate, benzenesulphinate and phenoxide anions have been used in nucleophilic substitution reactions for the synthesis of carboxylic acid esters, sulphones and C/O alkylation of phenols from alkyl halides. The polymeric reagent seems to increase the nucleophilicity of the anions376 and the yields are higher than those for corresponding polymer phase-transfer catalysis (reaction 273). 

The following reaction can be used to illustrate the synthesis of an ester from a carboxylic acid... 

The direct synthesis of aryl- or alkyl nitriles from cyanide and organohalide precursors is revered in synthetic chemistry, as the nitriles represent a flexible functionality that can easily be converted into (for example) carboxylic acids, esters, amides, amidines, amines and various hetero cycles [67], such as thiazoles, oxazolidones, triazoles and tetrazoles [68]. The tetrazole group... 

We have seen (Sec. 18.5) that in the carboxylic acids obtained from fats we have available long straight-chain units for. .se in organic synthesis. Reduction of these acids to alcohols (either directly or as esters) is a fundamental step in the utilization of these raw materials, since from the alcohols, as we know, a host of other compounds can be prepared (Sec. 16.10). Although only acids of even carbon number are available, it is possible, of course, to increase the chain length and thus prepare compounds of odd carbon number. (For an alternative source of alcohols both of even and odd carbon number, see Sec. 32.6.)... 

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