Diazomethane
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| Diazomethane | |
|---|---|
| Chemical name | Diazomethane |
| Chemical formula | CH2N2 |
| Molecular mass | 42.04 g/mol |
| Melting point | -145 °C |
| Boiling point | -23 °C |
| Density | 1.4 (air=1) |
| CAS number | [334-88-3] |
| SMILES | C=[N+]=[N-] |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Diazomethane which is a toxic, explosive yellow gas, is one of the more common diazo compounds. It is usually prepared as a solution in ether and often used in laboratory procedures for converting carboxylic acids into their methyl esters or into their homologues. Diazomethane is prepared in the laboratory at mmol scale from diazomethane precursors such as Diazald or N-methyl-N-nitroso-p-toluenesulfonamide and MNNG or 1-methyl-3-nitro-1-nitrosoguanidine. Diazald in a solution of diglyme and diethyl ether reacts with a solution of potassium hydroxide in water at elevated temperatures and generated diazomethane is collected by distillation. Diazomethane is liberated from a solution of MNNG in diethyl ether by addition of sodium hydroxide in water at low temperatures. Diazomethane may explode when in contact with ground-glass joints or when heated to about 100°C, and a blast shield should be employed for its use.
Image:Diazomethane precursors.gif
Toxic effects
Diazomethane is toxic by inhalation or by contact with the skin or eyes (TLV 0.2ppm). Symptoms include chest discomfort, headache, weakness and, in severe cases, collapse.<ref name="HitCL">Muir, GD (ed.) 1971, Hazards in the Chemical Laboratory, The Royal Institute of Chemistry, London.</ref>
References
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