 | |
 | |
| Names | |
|---|---|
| Preferred IUPAC name N-Methylmethanamine | |
| Other names (Dimethyl)amine | |
| Identifiers | |
| |
3D model (JSmol) | |
| 605257 | |
| ChEBI | |
| ChEMBL | |
| ChemSpider |
|
| ECHA InfoCard | 100.004.272 |
| EC Number |
|
| 849 | |
| KEGG |
|
| MeSH | dimethylamine |
| RTECS number |
|
| UNII | |
| UN number | 1032 |
| |
| |
| Properties[1][2] | |
| (CH3)2NH | |
| Molar mass | 45.085 g·mol−1 |
| Appearance | Colorless gas |
| Odor | Fishy, ammoniacal |
| Density | 649.6 kg m−3 (at 25 °C) |
| Melting point | −93.00 °C; −135.40 °F; 180.15 K |
| Boiling point | 7 to 9 °C; 44 to 48 °F; 280 to 282 K |
| 1.540 kg L−1 | |
| logP | −0.362 |
| Vapor pressure | 170.3 kPa (at 20 °C) |
Henry's law constant (kH) | 310 μmol Pa−1 kg−1 |
| Basicity (pKb) | 3.29 |
| Thermochemistry | |
Std enthalpy of formation(ΔfH⦵298) | −21 to −17 kJ mol−1 |
| Hazards | |
| GHS labelling: | |
   | |
| Danger | |
| H220,H302,H315,H318,H332,H335 | |
| P210,P261,P280,P305+P351+P338 | |
| NFPA 704 (fire diamond) | |
| Flash point | −6 °C (21 °F; 267 K) (liquid) |
| 401 °C (754 °F; 674 K) | |
| Explosive limits | 2.8–14.4% |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 698 mg/kg (rat, oral) 316 mg/kg (mouse, oral) 240 mg/kg (rabbit, oral) 240 mg/kg (guinea pig, oral)[4] |
LC50 (median concentration) | 4700 ppm (rat, 4 hr) 4540 ppm (rat, 6 hr) 7650 ppm (mouse, 2 hr)[4] |
| NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 10 ppm (18 mg/m3)[3] |
REL (Recommended) | TWA 10 ppm (18 mg/m3)[3] |
IDLH (Immediate danger) | 500 ppm[3] |
| Related compounds | |
Related amines | |
Related compounds | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Dimethylamine is anorganic compound with the formula (CH3)2NH. Thissecondary amine is a colorless, flammable gas with anammonia-like odor. Dimethylamine is commonly encountered commercially as a solution in water at concentrations up to around 40%. An estimated 270,000 tons were produced in 2005.[5]
The molecule consists of anitrogenatom with twomethylsubstituents and onehydrogen. Dimethylamine is aweak base and thepKa of theammonium CH3-NH+
2-CH3 is 10.73, a value abovemethylamine (10.64) andtrimethylamine (9.79).
Dimethylamine reacts with acids to form salts, such as dimethylamine hydrochloride, an odorless white solid with a melting point of 171.5 °C. Dimethylamine is produced bycatalytic reaction ofmethanol andammonia at elevated temperatures and high pressure:[6]
Dimethylamine is found quite widely distributed in animals and plants, and is present in many foods at the level of a few mg/kg.[7]
Dimethylamine is a precursor to several industrially significant compounds.[5][8] It reacts withcarbon disulfide to give dimethyldithiocarbamate, a precursor tozinc bis(dimethyldithiocarbamate) and other chemicals used in thesulfur vulcanization ofrubber.Dimethylaminoethoxyethanol is manufactured by reacting dimethylamine andethylene oxide.[9] Other methods are also available producing streams rich in the substance which then need to be further purified.[10] The solventsdimethylformamide anddimethylacetamide are derived from dimethylamine. It is raw material for the production of manyagrichemicals andpharmaceuticals, such asdimefox anddiphenhydramine, respectively. Thechemical weapontabun is derived from dimethylamine. Thesurfactantlauryl dimethylamine oxide is found insoaps and cleaning compounds.Unsymmetrical dimethylhydrazine, a rocket fuel, is prepared from dimethylamine.[11]
It is an attractant forboll weevils.[12]
It is basic, in both theLewis[13][14] andBrønsted senses. It easily formsdimethylammonium salts upon treatment with acids. Deprotonation of dimethylamine can be effected withorganolithium compounds. The resulting LiNMe2, which adopts a cluster-like structure, serves as a source of Me2N−. This lithium amide has been used to prepare volatile metal complexes such astetrakis(dimethylamido)titanium andpentakis(dimethylamido)tantalum.
It reacts with many carbonyl compounds. Aldehydes give aminals. For example reaction of dimethylamine andformaldehyde givesbis(dimethylamino)methane:[15]
It converts esters to dimethylamides.
Dimethylamine is not very toxic with the following LD50 values: 736 mg/kg (mouse, i.p.); 316 mg/kg (mouse, p.o.); 698 mg/kg (rat, p.o.); 3900 mg/kg (rat, dermal); 240 mg/kg (guinea pig or rabbit, p.o.).[16]
Although not acutely toxic, dimethylamine undergoesnitrosation to givedimethylnitrosamine, a carcinogen.
