Methylamine
From Wikipedia, the free encyclopedia
| Methylamine | |
|---|---|
 |
 |
 |
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| IUPAC name | aminomethane |
| Other names | monomethylamine MMA |
| Identifiers | |
| CAS number | [74-89-5] |
| RTECS number | PF6300000 |
| SMILES | CN |
| Properties | |
| Molecular formula | CH5N |
| Molar mass | 31.1 g/mol |
| Appearance | Colorless Gas |
| Density | 0.902 g/cm³, 40w/w% in water |
| Melting point |
-94 °C (179.15K) |
| Boiling point |
-6 °C (267.2 K) |
| Solubility in water | 108 g/100 mL (20 °C) |
| Acidity (pKa) | 10.64 (value for protonated amine, pKaH) |
| Basicity (pKb) | 3.36 |
| Viscosity | 0.23 cP at 0 °C |
| Structure | |
| Molecular shape | tetrahedral |
| Dipole moment | 1.31 D (gas) |
| Hazards | |
| MSDS | From EMD Chemicals [1] |
| Main hazards | Corrosive liquid and gas, inhalation hazard, flammable. |
| NFPA 704 |
 4
3
0
|
| R-phrases | 11-36/37 (40% solution in water) |
| Flash point | 8 °C |
| Related compounds | |
| Related ? | Ammonia dimethylamine trimethylamine |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Methylamine is the chemical compound with a formula of CH3NH2. It is a derivative of ammonia, wherein one H atom is replaced by a methyl group. It is the simplest primary amine. It is usually sold as solutions in methanol (2M), ethanol (8M), THF (2M), and water (40%), or as the anhydrous gas in pressurized metal containers. It has a strong odour similar to rotten fish. Methylamine is used as a building block for the synthesis of other organic compounds, including many illicit drugs; in the United States, the DEA lists methylamine as a precursor, and purchases of any significant quantity are likely to arouse law enforcement attention.
[edit] Chemistry
Methylamine is a good nucleophile as it is highly basic and unhindered. Its use in organic chemistry is pervasive. For example, it is a precursor to CH3NCS.[1]
The hydrochloride salt of methylamine, methylammonium chloride, CH3NH3Cl, is a colourless powder that can be converted to the amine.
Although methylamine is a gas at room temperature, liquid methylamine can be used as a solvent analogous to liquid ammonia. It shares some of the properties of liquid ammonia, but is better for dissolving organic substances, in the same way that methanol is better than water.[2]
[edit] Production
Methylamine is prepared commercially by the reaction of ammonia with methanol with zeolite as catalyst.[3]
- CH3OH + NH3 → CH3NH2 + H2O
It can also be readily prepared as the hydrochloride by the reaction of hydrochloric acid with hexamine or by the reaction of formaldehyde with ammonium chloride.[4]
- NH4Cl + H2CO → CH2=NH·HCl + H2O
- CH2=NH·HCl + H2CO + H2O → CH3NH2·HCl + HCOOH
Methylamine serves as a buffering agent in the lumen of the chloroplast in plants, effectively siphoning off protons that are heading for ATP synthase.[citation needed]
[edit] References
- ^ Moore, M. L.; Crossley, F. S. (1955). "Methyl Isothiocyanate". Org. Synth.; Coll. Vol. 3: 599.
- ^ H. D. Gibbs (1906). "Liquid methylamine as a solvent, and a study of its chemical reactivity". J. Am. Chem. Soc. 28: 1395-1422. doi:.
- ^ Corbin D.R.; Schwarz S.; Sonnichsen G.C. (1997). "Methylamines synthesis: A review". Catalysis Today 37 (2): 71-102. doi:.
- ^ Marvel, C. S.; Jenkins, R. L. (1941). "Methylamine Hydrochloride". Org. Synth.; Coll. Vol. 1: 347.
