How are following compounds prepared using ethereal solution of diazomethane?Write the mechanism of the reactions CH3CH2COOCH3
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Diazomethane and other diazoalkyl derivatives have long been used to label carboxylate groups for analysis (Herriott, 1947; Riehm and Scheraga, 1965). A major application of such reagents has been in the HPLC analysis of low-molecular-weight compounds such as fatty acids (DeMar et al., 1992). Several coumarin derivatives containing stable, carboxylate-reactive diazoalkane functionalities are also available for fluorescent labeling of target molecules (Molecular Probes) (Ito and Sawanobori, 1982; Ito and Maruyama, 1983).
Diazoalkanes and diazoacetyl compounds (amides and esters) are spontaneously reactive with carboxylate groups without addition of other reactants or catalysts. The reaction mechanism involves attack of a negatively charged carboxylate oxygen atom on a protonated diazoalkyl group, liberating nitrogen gas and forming a covalent linkage (Reaction 3.30).
The reaction with carboxylates occurs over a range of pH values, but is optimal at pH 5.0. Unfortunately, the diazoalkyl compounds will cross-react with sulfhydryl groups at this pH. At higher pH conditions, the reaction is even less specific due to reaction with other nucleophiles. In aqueous solution, the most-likely side reaction is hydrolysis.
hope you have understood..
Diazoalkanes and diazoacetyl compounds (amides and esters) are spontaneously reactive with carboxylate groups without addition of other reactants or catalysts. The reaction mechanism involves attack of a negatively charged carboxylate oxygen atom on a protonated diazoalkyl group, liberating nitrogen gas and forming a covalent linkage (Reaction 3.30).
The reaction with carboxylates occurs over a range of pH values, but is optimal at pH 5.0. Unfortunately, the diazoalkyl compounds will cross-react with sulfhydryl groups at this pH. At higher pH conditions, the reaction is even less specific due to reaction with other nucleophiles. In aqueous solution, the most-likely side reaction is hydrolysis.
hope you have understood..
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