Names | |
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Preferred IUPAC name Dimethylcarbamoyl chloride | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.001.099 |
PubChem CID | |
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). |
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]
Dimethylcarbamoyl chloride is a clear, colorless, corrosive and flammable liquid with a pungent odor and a tear-penetrating effect, which decomposes rapidly in water. [10] Because of its unpleasant, toxic, mutagenic and carcinogenic properties, [11] [12] it has to be used under extreme precautions.
DMCC behaves like an acyl chloride whose chlorine atom can be exchanged for other nucleophiles. Therefore, it reacts with alcohols, phenols and oximes to the corresponding N,N-dimethylcarbamates, with thiols to thiolourethanes, with amines and hydroxylamines to substituted ureas, and with imidazoles and triazoles to carbamoylazoles. [10]
DMCC is less reactive and less selective to substrates with multiple nucleophilic centers than conventional acyl chlorides.
Unsaturated conjugated aldehydes such as crotonaldehyde (trans-but-2-enal) react with DMCC forming dienyl carbamates, which can be used as dienes in Diels–Alder reactions. [13]
Alkali metal carboxylates react with DMCC forming the corresponding dimethylamides. DMCC reacts with anhydrous sodium carbonate [14] or with excess dimethylamine to form tetramethylurea. [15]
The reaction of DMCC with DMF forms tetramethylformamidinium chloride, [16] which is a major intermediate in the preparation of tris(dimethylamino)methane, a reagent for the introduction of enamine functions in conjunction with activated methylene groups [17] and the preparation of amidines. [18]
DMCC is a starting material for the insecticide class of the dimethyl carbamates which act as inhibitors of acetylcholinesterase, including dimetilane, [19] and the related compounds isolane, pirimicarb and triazamate.
The quaternary ammonium compounds neostigmine [20] finds pharmaceutical applications as acetylcholinesterase inhibitors. It is obtained from 3-(dimethylamino)phenol and DMCC and subsequent quaternization with methyl bromide or dimethyl sulfate [21]
and pyridostigmine, which is obtainable from 3-hydroxypyridine and DMCC and subsequent reaction with methyl bromide. [22]
DMCC is also used in the synthesis of the benzodiazepine camazepam. [23]
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis.
In organic chemistry, an acyl chloride is an organic compound with the functional group −C(=O)Cl. Their formula is usually written R−COCl, where R is a side chain. They are reactive derivatives of carboxylic acids. A specific example of an acyl chloride is acetyl chloride, CH3COCl. Acyl chlorides are the most important subset of acyl halides.
In organic chemistry, an acyl halide is a chemical compound derived from an oxoacid by replacing a hydroxyl group with a halide group.
Triphosgene (bis(trichloromethyl) carbonate (BTC) is a chemical compound with the formula OC(OCCl3)2. It is used as a solid substitute for phosgene, which is a gas and diphosgene, which is a liquid. Triphosgene is stable up to 200 °C. Triphosgene is used in a variety of halogenation reactions.
Dimethylformamide, DMF is an organic compound with the chemical formula HCON(CH3)2. Its structure is HC(=O)−N(−CH3)2. Commonly abbreviated as DMF, this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless, but technical-grade or degraded samples often have a fishy smell due to impurity of dimethylamine. Dimethylamine degradation impurities can be removed by sparging samples with an inert gas such as argon or by sonicating the samples under reduced pressure. As its name indicates, it is structurally related to formamide, having two methyl groups in the place of the two hydrogens. DMF is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as SN2 reactions.
Oxalyl chloride is an organic chemical compound with the formula Cl−C(=O)−C(=O)−Cl. This colorless, sharp-smelling liquid, the diacyl chloride of oxalic acid, is a useful reagent in organic synthesis.
Thionyl chloride is an inorganic compound with the chemical formula SOCl2. It is a moderately volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a chlorinating reagent, with approximately 45,000 tonnes per year being produced during the early 1990s, but is occasionally also used as a solvent. It is toxic, reacts with water, and is also listed under the Chemical Weapons Convention as it may be used for the production of chemical weapons.
Phosphorus pentachloride is the chemical compound with the formula PCl5. It is one of the most important phosphorus chlorides/oxychlorides, others being PCl3 and POCl3. PCl5 finds use as a chlorinating reagent. It is a colourless, water-sensitive solid, although commercial samples can be yellowish and contaminated with hydrogen chloride.
N-Bromosuccinimide or NBS is a chemical reagent used in radical substitution, electrophilic addition, and electrophilic substitution reactions in organic chemistry. NBS can be a convenient source of Br•, the bromine radical.
Cyanuric chloride is an organic compound with the formula (NCCl)3. This white solid is the chlorinated derivative of 1,3,5-triazine. It is the trimer of cyanogen chloride. Cyanuric chloride is the main precursor to the popular but controversial herbicide atrazine.
The Curtius rearrangement, first defined by Theodor Curtius in 1885, is the thermal decomposition of an acyl azide to an isocyanate with loss of nitrogen gas. The isocyanate then undergoes attack by a variety of nucleophiles such as water, alcohols and amines, to yield a primary amine, carbamate or urea derivative respectively. Several reviews have been published.
1,1'-Carbonyldiimidazole (CDI) is an organic compound with the molecular formula (C3H3N2)2CO. It is a white crystalline solid. It is often used for the coupling of amino acids for peptide synthesis and as a reagent in organic synthesis.
Oseltamivir total synthesis concerns the total synthesis of the anti-influenza drug oseltamivir marketed by Hoffmann-La Roche under the trade name Tamiflu. Its commercial production starts from the biomolecule shikimic acid harvested from Chinese star anise and from recombinant E. coli. Control of stereochemistry is important: the molecule has three stereocenters and the sought-after isomer is only 1 of 8 stereoisomers.
The Bergmann degradation is a series of chemical reactions designed to remove a single amino acid from the carboxylic acid (C-terminal) end of a peptide. First demonstrated by Max Bergmann in 1934, it is a rarely used method for sequencing peptides. The later developed Edman degradation is an improvement upon the Bergmann degradation, instead cleaving the N-terminal amino acid of peptides to produce a hydantoin containing the desired amino acid.
Imidoyl chlorides are organic compounds that contain the functional group RC(NR')Cl. A double bond exist between the R'N and the carbon centre. These compounds are analogues of acyl chloride. Imidoyl chlorides tend to be highly reactive and are more commonly found as intermediates in a wide variety of synthetic procedures. Such procedures include Gattermann aldehyde synthesis, Houben-Hoesch ketone synthesis, and the Beckmann rearrangement. Their chemistry is related to that of enamines and their tautomers when the α hydrogen is next to the C=N bond. Many chlorinated N-heterocycles are formally imidoyl chlorides, e.g. 2-chloropyridine, 2, 4, and 6-chloropyrimidines.
Tetramethylurea is the organic compound with the formula (Me2N)2CO. It is a substituted urea. This colorless liquid is used as an aprotic-polar solvent, especially for aromatic compounds and is used e. g. for Grignard reagents.
N,N,N′,N′-Tetramethylformamidinium chloride is the simplest representative of quaternary formamidinium cations of the general formula [R2N−CH=NR2]+ with a chloride as a counterion in which all hydrogen atoms of the protonated formamidine [HC(=NH2)NH2]+ are replaced by methyl groups.
Tris(dimethylamino)methane (TDAM) is the simplest representative of the tris(dialkylamino)methanes of the general formula (R2N)3CH in which three of the four of methane's hydrogen atoms are replaced by dimethylamino groups (−N(CH3)2). Tris(dimethylamino)methane can be regarded as both an amine and an orthoamide.
3-Dimethylaminoacrolein is an organic compound with the formula Me2NC(H)=CHCHO. It is a pale yellow water-soluble liquid. The compound has a number of useful and unusual properties, e.g. it "causes a reversal of the hypnotic effect of morphine in mice" and has a "stimulating effect in humans".
tert-Butoxybis(dimethylamino)methane is an organic compound with the formula (CH3)3COCH(N(CH3)2)2. The compound is classified as an aminal ester, i.e. the tert-butyl alcohol derivative of the aminal bis(dimethylamino)methane. It is a colorless liquid with a amine odor.
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