Dimethylcarbamoyl chloride
From Wikipedia, the free encyclopedia
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| Preferred IUPAC name
Dimethylcarbamoyl chloride | |
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3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.001.099 |
PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C3H6ClNO | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Dimethylcarbamoyl chloride (DMCC) is a reagent for transferring a dimethylcarbamoyl group to alcoholic or phenolic hydroxyl groups forming dimethyl carbamates, usually having pharmacological or pesticidal activities. Because of its high toxicity and its carcinogenic properties shown in animal experiments and presumably also in humans,[1] dimethylcarbamoyl chloride can only be used under stringent safety precautions.
The production of dimethylcarbamoyl chloride from phosgene and dimethylamine was reported as early as 1879 (reported as "Dimethylharnstoffchlorid" – dimethylurea chloride).[2]
DMCC can be produced in high yields (90%) at 275 °C by reacting phosgene with gaseous dimethylamine in a flow reactor.[3] To suppress the formation of ureas, excess phosgene is used (in a 3:1 ratio).
The reaction can also be carried out at the laboratory scale with diphosgene or triphosgene and an aqueous dimethylamine solution in the two-phase system of benzene–xylene and water in a stirred reactor with sodium hydroxide as an acid scavenger. However, considerably lower yields (56%) are achieved due to the hydrolysis sensitivity of DMCC.[4]
Dimethylcarbamoyl chloride is also formed (together with methyl chloride) when reacting phosgene with trimethylamine.[5]
A more recent process is based on chlorodimethylamine, which is converted practically quantitatively to dimethylcarbamoyl chloride on a palladium catalyst under pressure with carbon monoxide at room temperature.[6]
DMCC can also be formed in small amounts (up to 20 ppm) from dimethylformamide (DMF) in the Vilsmeier–Haack reaction[7] or when DMF is used as a catalyst in the reaction of carboxylic acids with thionyl chloride to the corresponding acyl chloride.[8]
The tendency towards DMCC formation depends on the chlorination reagent (thionyl chloride > oxalyl chloride > phosphorus oxychloride) and is higher in the presence of a base. However, dicarbamoyl chloride hydrolyses very quickly to dimethylamine, hydrochloric acid and carbon dioxide (with a half-life of about 6 minutes at 0 °C) so that less than 3 ppm of dicarbamoyl chloride is found in the Vilsmeier product after aqueous workup.[9]











