Esterif cation with Alkyl Halides

Alkyl (aryl) iodides, bromides (less often chlorides) have been used for treatment of potassium, i-amines, tetraalkylammonium or 'crown' ether salts of acids in a suitable organic solvent such as acetonitrile, acetone or methanol. Corresponding alkyl/aryl esters are formed without heating the sample at optimum conditions in high yields. It has been reported by Wells and co-workers (see Further Reading) that macroporous quaternary ammonium anion exchange resins are a very effective support matrix for the methylation of strongly acidic organic analytes with methyl iodide in either supercritical carbon dioxide or acetonitrile. The isolation and determination of simple volatile aliphatic acids from urine by trapping on ion exchange resin followed by simultaneous derivatization with pentafluorobenzyl bromide (PFBBr) and extraction with supercritical carbon dioxide has also been reported. The electron-capturing pentafluorobenzyl (PFB) esters have become increasingly popular for GC-ECD analysis of fatty acids regardless of chain length. Conversion to PFB esters has been reported to succeed in the presence of acetonitrile and diisop-ropylethylamine in 10 min.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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