Search results
Results From The WOW.Com Content Network
If excess diazomethane is present during the reaction, it can act as a base, abstracting a hydrogen from the diazonium-salt intermediate. The result is a neutral diazoketone, which does not react with the chloride. Instead, the byproduct, diazonium-methyl from the other diazomethane molecule, can be attacked by the chloride to produce ...
Diazomethane is an organic chemical compound with the formula CH 2 N 2, discovered by German chemist Hans von Pechmann in 1894. It is the simplest diazo compound.In the pure form at room temperature, it is an extremely sensitive explosive yellow gas; thus, it is almost universally used as a solution in diethyl ether.
Diazo compounds can be obtained in an elimination reaction of N-alkyl-N-nitroso compounds, [14] such as in the synthesis of diazomethane from Diazald or MNNG: (The mechanism shown here is one possibility. [15] For an alternative mechanism for the analogous formation of diazomethane from an N-nitrososulfonamide, see the page on Diazald.)
In one study, the silicon surface is washed with ammonium hydrogen fluoride leaving it covered with silicon–hydrogen bonds (hydride passivation). [41] The reaction of the surface with a solution of diazonium salt in acetonitrile for 2 hours in the dark is a spontaneous process through a free radical mechanism: [42]
In the reaction between o-nitropiperonal (IX) and diazomethane, an aryl shift leads to production of the epoxide (X) in 9 to 1 excess of the ketone product (XI). When diazoethane is substituted for diazomethane, a hydride shift produces the ketone (XII), the only isolable product.
In organic chemistry, a homologation reaction, also known as homologization, is any chemical reaction that converts the reactant into the next member of the homologous series. A homologous series is a group of compounds that differ by a constant unit, generally a methylene ( −CH 2 − ) group.
Methylene from diazomethane photolysis reacts with either cis- or trans-2-butene to give a single diastereomer of 1,2-dimethylcyclopropane: cis from cis and trans from trans. Thus methylene is a singlet carbene; if it were triplet, the product would not depend on the starting alkene geometry.
The diazomethane is required in excess so as to react with the HCl formed previously. [2] Not taking diazomethane in excess results in HCl reacting with the diazoketone to form chloromethyl ketone and N 2. Mild conditions allow this reaction to take place while not affecting complex or reducible groups in the reactant-acid. [3]