Search results
Results From The WOW.Com Content Network
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 .
It is possible to isolate nitrogen-containing compounds using the Büchner–Curtius–Schlotterbeck reaction. For example, an acyl-diazomethane can react with an aldehyde in the presence of a DBU catalyst to form isolable α-diazo-β-hydroxy esters (shown below). [27]
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.)
Diazomethane reacts with the electron-poor ethyl acrylate more than a million times faster than the electron rich butyl vinyl ether. [ 17 ] This type resembles the normal-electron-demand Diels-Alder reaction, in which the diene HOMO combines with the dienophile LUMO.
Aside from the acid chloride substrate, three reagents are required: diazomethane, water, and a metal catalyst. Each has been well investigated. 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 ...
This carboxylic acid is then reacted with diazomethane in diethyl ether to form the methyl ester. The BOC group is removed by reaction with gaseous hydrogen chloride in methanol, and the amino group is protected with 2,4-dinitrobenzenesulfonyl chloride using 2,6-lutidine as the base.
The mixture was shaken vigorously for 5 min and then extracted with ether (3 x 50 ml). The combined ethereal extracts were washed with saturated sodium bicarbonate solution (4 X 40 ml), water (40 ml), and saturated sodium chloride solution (40 ml), dried (Na 2 SO 4 ), and concentrated in vacuo to give 0.673 g of a crude brown oil.
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 ...