Grignard reagents carboxylic acids

SYNTHESIS OF CARBOXYLIC ACIDS BY THE CARBOXYLATION OF GRIGNARD REAGENTS... 

Synthesis of Carboxylic Acids by the Carboxylation of Grignard Reagents... 

Overall the carboxylation of Grignard reagents transforms an alkyl or aryl halide to a carboxylic acid in which the carbon skeleton has been extended by one carbon atom... 

Show how to synthesize carboxylic acids from oxidation of alcohols and aldehydes. Problems 20-36, 39, and 44 carboxylation of Grignard reagents, oxidative cleavage of alkenes and alkynes, hydrolysis of nitriles, and oxidation of alkylbenzenes. 

FIGURE 17.18 A general route to carboxylic acids uses the carboxylation of Grignard reagents with carbon dioxide. 

Preparation of carboxylic acids (Section 20.5) (a) Carboxylation of Grignard reagents... 

FIGURE 19.38 Preparation of carboxylic acids by carboxylation of Grignard reagents. 

We ve seen how Grignard reagents add to the carbonyl group of aldehydes ketones and esters Grignard reagents react m much the same way with carbon dioxide to yield mag nesium salts of carboxylic acids Acidification converts these magnesium salts to the desired carboxylic acids... 

Among the methods for preparing carboxylic acids carboxylation of a Grignard reagent and preparation and hydrolysis of a nitrile convert RBr to RCO2H The malonic ester synthesis converts RBr to RCH2CO2H... 

In some instances a carbon-carbon bond can be formed with C-nucleophiles. For example, 3-carboxamido-6-methylpyridazine is produced from 3-iodo-6-methylpyridazine by treatment with potassium cyanide in aqueous ethanol and l,3-dimethyl-6-oxo-l,6-dihydro-pyridazine-4-carboxylic acid from 4-chloro-l,3-dimethylpyridazin-6-(lH)-one by reaction with a mixture of cuprous chloride and potassium cyanide. Chloro-substituted pyridazines react with Grignard reagents. For example, 3,4,6-trichloropyridazine reacts with f-butyl-magnesium chloride to give 4-t-butyl-3,5,6-trichloro-l,4-dihydropyridazine (120) and 4,5-di-t-butyl-3,6-dichloro-l,4-dihydropyridazine (121) and both are converted into 4-t-butyl-3,6-dichloropyridazine (122 Scheme 38). 

Grignard reagents can be successfully prepared from 4-iodoisoxazoles and these react with CO2 and ketones to give carboxylic acids and methanols, respectively. 3-Bromo- or... 

Isoxazolyl Grignard reagents react normally in that a 4-carboxylic acid or 4-methanol can be obtained by reaction with CO2 or ketones (63AHC(2)365). Lithiation of 3,5-disub-... 

Grignard reagent from, acylation, 4, 237 nitration, 4, 211 reactivity, 4, 71-72 synthesis, 4, 149, 237, 341, 360 Pyrrole-3-carboxylic acids acidity, 4, 71 decarboxylation, 4, 286 esterification, 4, 287 esters... 

The other three methods have not been studied extensively. The dimethyl-cadmium route has been used on a 17a-methyl-17 -carboxylic acid. ° The reaction of the acid amide with a Grignard reagent is described only in a Spanish patent,with a high yield claimed, and the methyllithium reaction has apparently been tried only on D-norsteroids. ... 

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