Methyldiazonium is an organic compound consisting of a methyl group attached to a diazo group. This cation is the conjugate acid of diazomethane, with an estimated pKa<10.
It is an intermediate in methylation reactions of diazomethane with acidic hydroxyl compounds, such as conversion of carboxylic acids to methyl esters and phenols to methyl ethers.
It has been implicated as the metabolite of N-nitrosodimethylamine responsible for the observed carcinogenicity of that compound.
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