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| Names | |||
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| Pronunciation | /ˌmɛθələˈmiːn/ (METH-ə-lə-MEEN),/ˌmɛθəˈlæmən/ (METH-ə-LA-mən),/məˈθɪləˌmiːn/ (mə-THIL-ə-meen)[2] | ||
| Preferred IUPAC name Methanamine[1] | |||
Other names
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| Identifiers | |||
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3D model (JSmol) | |||
| Abbreviations | MMA | ||
| 741851 | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider |
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| DrugBank |
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| ECHA InfoCard | 100.000.746 | ||
| EC Number |
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| 145 | |||
| KEGG |
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| MeSH | methylamine | ||
| RTECS number |
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| UNII | |||
| UN number | 1061 | ||
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| Properties | |||
| CH3NH2 | |||
| Molar mass | 31.058 g·mol−1 | ||
| Appearance | Colorless gas | ||
| Odor | Fishy, ammoniacal | ||
| Density | 0.6562 g/cm3 (at 25 °C) | ||
| Melting point | −93.10 °C; −135.58 °F; 180.05 K | ||
| Boiling point | −6.6 to −6.0 °C; 20.0 to 21.1 °F; 266.5 to 267.1 K | ||
| 1008 g/L (at 20 °C) | |||
| logP | −0.472 | ||
| Vapor pressure | 186.10 kPa (at 20 °C) | ||
Henry's law constant (kH) | 1.4 mmol/(Pa·kg) | ||
| Acidity (pKa) | 10.66 | ||
| Conjugate acid | [CH3NH3]+ (Methylammonium) | ||
| −27.0·10−6 cm3/mol | |||
| Viscosity | 230 μPa·s (at 0 °C) | ||
| 1.31 D | |||
| Thermochemistry | |||
Std enthalpy of formation(ΔfH⦵298) | −23.5 kJ/mol | ||
| Hazards | |||
| GHS labelling: | |||
   | |||
| Danger | |||
| H220,H315,H318,H332,H335 | |||
| P210,P261,P280,P305+P351+P338,P410+P403 | |||
| NFPA 704 (fire diamond) | |||
| Flash point | −10 °C; 14 °F; 263 K (liquid, gas is extremely flammable)[3] | ||
| 430 °C (806 °F; 703 K) | |||
| Explosive limits | 4.9–20.7% | ||
| Lethal dose or concentration (LD, LC): | |||
LD50 (median dose) | 100 mg/kg (oral, rat) | ||
LC50 (median concentration) | 1860 ppm (mouse, 2 hr)[3] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | TWA 10 ppm (12 mg/m3)[3] | ||
REL (Recommended) | TWA 10 ppm (12 mg/m3)[3] | ||
IDLH (Immediate danger) | 100 ppm[3] | ||
| Safety data sheet (SDS) | emdchemicals.com | ||
| Related compounds | |||
Related alkanamines | ethylamine,dimethylamine,trimethylamine | ||
Related compounds | ammonia | ||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Methylamine, also known asmethanamine, is anorganic compound with aformula ofCH3NH2. This colorless gas is a derivative ofammonia, but with one hydrogen atom being replaced by amethyl group. It is the simplest primaryamine.
Methylamine is sold as a solution inmethanol,ethanol,tetrahydrofuran, orwater, or as theanhydrous gas in pressurized metal containers. Industrially, methylamine is transported in its anhydrous form in pressurized railcars and tank trailers. It has a strong odor similar to rotten fish. Methylamine is used as a building block for the synthesis of numerous other commercially available compounds.
Methylamine has been produced industrially since the 1920s (originally byCommercial Solvents Corporation for dehairing of animal skins).[4] This was made possible byKazimierz Smoleński [pl] and his wife Eugenia who discovered amination of alcohols, including methanol, on alumina or kaolin catalyst after WWI, filed two patent applications in 1919[5] and published an article in 1921.[4][6]
It is now prepared commercially by the reaction ofammonia withmethanol in the presence of analuminosilicate catalyst.Dimethylamine andtrimethylamine are co-produced; the reaction kinetics and reactant ratios determine the ratio of the three products. The product most favored by the reaction kinetics is trimethylamine.[4]
In this way, an estimated 115,000 tons were produced in 2005.[7]
Methylamine was first prepared in 1849 byCharles-Adolphe Wurtz via the hydrolysis ofmethyl isocyanate and related compounds.[7][8] An example of this process includes the use of theHofmann rearrangement, to yield methylamine fromacetamide andbromine.[9][10]
In the laboratory, methylaminehydrochloride is readily prepared by various other methods. One method entails treatingformaldehyde withammonium chloride.[11]
The colorless hydrochloride salt can be converted to an amine by the addition of a strong base, such assodium hydroxide (NaOH):
Another method entails reducingnitromethane withzinc and hydrochloric acid.[12]
Another method of methylamine production is spontaneous decarboxylation ofglycine with a strong base in water.[13]
Methylamine arises as a result ofputrefaction and is a substrate formethanogenesis.[14]
Additionally, methylamine is produced duringPADI4-dependentargininedemethylation.[15]
Methylamine is a goodnucleophile as it is an unhinderedamine.[16] As an amine it is considered aweak base. Its use inorganic chemistry is pervasive. Some reactions involving simple reagents include: withphosgene tomethyl isocyanate, withcarbon disulfide andsodium hydroxide to the sodium methyldithiocarbamate, withchloroform and base tomethyl isocyanide and withethylene oxide tomethylethanolamines. Liquid methylamine has solvent properties analogous to those ofliquid ammonia.[17]
Representative commercially significant chemicals produced from methylamine include the pharmaceuticalsephedrine andtheophylline, the pesticidescarbofuran,carbaryl, andmetham sodium, and the solventsN-methylformamide andN-methylpyrrolidone. The preparation of somesurfactants and photographic developers require methylamine as a building block.[7]
TheLD50 (mouse,s.c.) is 2.5 g/kg.[18]
TheOccupational Safety and Health Administration (OSHA) andNational Institute for Occupational Safety and Health (NIOSH) have set occupational exposure limits at 10 ppm or 12 mg/m3 over an eight-hour time-weighted average.[19]
In the United States, methylamine is controlled as aList 1precursor chemical by theDrug Enforcement Administration[20] due to its use in the illicit production ofmethamphetamine.[21]
Fictional charactersWalter White andJesse Pinkman useaqueous methylamine as part of a process to synthesizemethamphetamine in theAMC seriesBreaking Bad.[22][23]
{{cite book}}:ISBN / Date incompatibility (help)...an unhindered amine such as methylamine
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