Diazomethane

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diazomethane

[dī¦a·zō′me‚thān]
(organic chemistry)
CH2N2 A poisonous gas used in organic synthesis to methylate compounds.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Diazomethane

 

the very simple acyclic diazo compound CH2N2; a highly toxic and explosive yellowish gas with an unpleasant odor. Melting point, -145°C; boiling point, -23° C. The structure of diazomethane can be represented by the following formulas: Diazomethane.

Diazomethane is usually produced by treating nitrosomethylurea (1) or nitrosomethylurethane (2) with an alkali:

Diazomethane may react with or without the liberation of nitrogen. The most important reactions of diazomethane involve the liberation of N2: the generation of carbene upon pyrolysis or photolysis of diazomethane or under the catalytic action of powdered copper:

(3) CH2N2→:CH2+N2

reactions with acids, phenols, and alcohols, with the formation of corresponding methyl ethers and esters, such as

(4) CH3COOH + CH2N2→CH3COOCH3 + N2

and interaction with halogens and halides of other elements:

Diazomethane

Diazomethane reacts without the liberation of nitrogen with such compounds as the acid halides of carboxylic acids, resulting in the production of diazoketones. When the diazoketones decompose in the presence of water, alcohols, or amines and a catalyst (Ag2O), regrouping takes place, resulting in the formation of an acid (its ester or amide) with one more carbon atom than in the initial acid chloride (the Arndt-Eistert reaction):

Diazomethane

The synthesis of carboxylic acids is one of the most important applications of diazomethane; it is also used extensively as a methylizing agent.

B. L. DIATKIN

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
A 15 ml yellow dimethylether solution of diazomethane, ready for use and prepared by adding alcoholic solution of KOH to 300 mg of Diazald, was poured into 0.5 g of polymer while stirring.
(1) Na [CP'M[(CO).sub.3] + Diazald (in THF) CP'M[(CO).sub.2](NO)..............