Pyrazole 2-oxide, 1-methyl-, nitration

In some cases l-methyl-5-nitro- and l-methyl-3,5-dinitropyrazole can form as a result of deoxygenation [76], Nevetheless, the nitration of 2-benzylpyrazole 1-oxide by sulfuric-nitric acid mixture leads to 2-benzyl-3-nitropyrazole 1-oxide in quantitative yield. Further nitration takes place in the phenyl 4-position forming 3-nitro-2-(4-nitrobenzyl)pyrazole 1-oxide and then in the pyrazole 5-position to give 3,5-dinitro-2-(4-nitrobenzyl)pyrazole 1-oxide as the final product [77],... 

Oxidation of 5-Substituted Pyrazol-3(2H)-ones Formation of Alkynyl Esters. Oxidation of various 5-substituted pyrazol-3(2//)-ones proceeded with fragmentative loss of molecular nitrogen to yield methyl-2-alkynoates (eq 35). An analogous fragmentation process with pyrazol-3(2//)-ones occurs with Thallium(III) Nitrate Trihydrate and Lead(IV) Acetate. ... 

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