Methylamine

Organic chemical compound

Methylamine

|

Names
Pronunciation  | /ˌmɛθələˈmiːn/
(METH-ə-lə-MEEN), /ˌmɛθəˈlæmən/
(METH-ə-LA-mən), /məˈθɪləˌmiːn/
(mə-THIL-ə-meen)[2]
Preferred IUPAC name

Methanamine[1]

Other names

* Aminomethane
* Monomethylamine

Identifiers

CAS Number

* 74-89-5 Y

3D model (JSmol)

* Interactive image

3DMet  |

* B00060

Abbreviations  | MMA

Beilstein Reference

| 741851
ChEBI |

* CHEBI:16830 N

ChEMBL |

* ChEMBL43280 Y

ChemSpider |

* 6089 Y

DrugBank |

* DB01828 N

ECHA InfoCard | 100.000.746
EC Number |

* 200-820-0

Gmelin Reference

| 145
KEGG |

* C00218 Y

MeSH | methylamine

PubChem CID

* 6329

RTECS number |

* PF6300000

UNII |

* BSF23SJ79E Y

UN number | 1061

CompTox Dashboard (EPA)

* DTXSID7025683

InChI

* InChI=1S/CH5N/c1-2/h2H2,1H3 Y

Key: BAVYZALUXZFZLV-UHFFFAOYSA-N Y

SMILES

* CN

Properties

Chemical formula

| 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

Solubility in water

| 1008 g/L (at 20 °C)
log P | −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)

Magnetic susceptibility (χ)

| -27.0·10−6 cm3/mol
Viscosity | 230 μPa·s (at 0 °C)

Dipole moment

| 1.31 D
Thermochemistry

Std enthalpy of
formation (ΔfH⦵298)

| −23.5 kJ/mol
Hazards
GHS labelling:

Pictograms

Signal word

| Danger

Hazard statements

| H220, H315, H318, H332, H335

Precautionary statements

| 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]

Autoignition
temperature

| 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 their standard state (at 25 °C [77 °F], 100 kPa).

N verify (what is YN ?)

Infobox references

Chemical compound

Methylamine is an organic compound with a formula of CH3NH2. This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine.

Methylamine is sold as a solution in methanol, ethanol, tetrahydrofuran, or water, or as the anhydrous 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.

## Contents

* 1 Industrial production
* 2 Laboratory methods
* 3 Reactivity and applications
* 4 Biological chemistry
* 5 Safety
* 6 Regulation
* 7 In popular culture
* 8 See also
* 9 References

## Industrial production[edit]

Methylamine is prepared commercially by the reaction of ammonia with methanol in the presence of an aluminosilicate catalyst. Dimethylamine and trimethylamine 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]

CH3OH + NH3 → CH3NH2 \+ H2O

In this way, an estimated 115,000 tons were produced in 2005.[5]

## Laboratory methods[edit]

Methylamine was first prepared in 1849 by Charles-Adolphe Wurtz via the hydrolysis of methyl isocyanate and related compounds.[5][6] An example of this process includes the use of the Hofmann rearrangement, to yield methylamine from acetamide and bromine gas.[7][8]

In the laboratory, methylamine hydrochloride is readily prepared by various other methods. One method entails treating formaldehyde with ammonium chloride.[9]

[NH4]Cl + CH2O → [CH2=NH2]Cl + H2O
[CH2=NH2]Cl + CH2O + H2O → [CH3NH3]Cl + HCOOH

The colorless hydrochloride salt can be converted to an amine by the addition of a strong base, such as sodium hydroxide (NaOH):

[CH3NH3]Cl + NaOH → CH3NH2 \+ NaCl + H2O

Another method entails reducing nitromethane with zinc and hydrochloric acid.[10]

Another method of methylamine production is spontaneous decarboxylation of glycine with a strong base in water.[citation needed]

## Reactivity and applications[edit]

Methylamine is a good nucleophile as it is an unhindered amine.[11] As an amine it is considered a weak base. Its use in organic chemistry is pervasive. Some reactions involving simple reagents include: with phosgene to methyl isocyanate, with carbon disulfide and sodium hydroxide to the sodium methyldithiocarbamate, with chloroform and base to methyl isocyanide and with ethylene oxide to methylethanolamines. Liquid methylamine has solvent properties analogous to those of liquid ammonia.[12]

Representative commercially significant chemicals produced from methylamine include the pharmaceuticals ephedrine and theophylline, the pesticides carbofuran, carbaryl, and metham sodium, and the solvents N-methylformamide and N-methylpyrrolidone. The preparation of some surfactants and photographic developers require methylamine as a building block.[5]

## Biological chemistry[edit]

Methylamine arises as a result of putrefaction and is a substrate for methanogenesis.[13]

Additionally, methylamine is produced during PADI4-dependent arginine demethylation.[14]

## Safety[edit]

The LD50 (mouse, s.c.) is 2.5 g/kg.[15]

The Occupational Safety and Health Administration (OSHA) and National 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.[16]

## Regulation[edit]

In the United States, methylamine is controlled as a List 1 precursor chemical by the Drug Enforcement Administration[17] due to its use in the illicit production of methamphetamine.[18]

## In popular culture[edit]

Fictional characters Walter White and Jesse Pinkman use methylamine as part of a process to synthesize methamphetamine in the AMC series Breaking Bad. Its use becomes central to the plot line as an alternative to traditional methamphetamine production techniques that involve pseudoephedrine, a cold medication, with the protagonists committing multiple acts of theft to get it.

## See also[edit]

* Methylammonium halide

## References[edit]

1. ^ Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 670\. doi:10.1039/9781849733069-00648. ISBN 978-0-85404-182-4.
2. ^ "Methylamine Definition & Meaning". Retrieved 22 April 2022.`{{cite web}}`: CS1 maint: url-status (link)
3. ^ a b c d e NIOSH Pocket Guide to Chemical Hazards. "#0398". National Institute for Occupational Safety and Health (NIOSH).
4. ^ Corbin D.R.; Schwarz S.; Sonnichsen G.C. (1997). "Methylamines synthesis: A review". Catalysis Today. 37 (24): 71–102. doi:10.1016/S0920-5861(97)00003-5.
5. ^ a b c Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke "Amines, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a02_001
6. ^ Charles-Adolphe Wurtz (1849) "Sur une série d'alcalis organiques homologues avec l'ammoniaque" (On a series of homologous organic alkalis containing ammonia), Comptes rendus … , 28 : 223-226. Note: Wurtz's empirical formula for methylamine is incorrect because chemists in that era used an incorrect atomic mass for carbon (6 instead of 12).
7. ^ Mann, F. G.; Saunders, B. C. (1960). Practical Organic Chemistry (4th ed.). London: Longman. p. 128\. ISBN 9780582444072.
8. ^ Cohen, Julius (1900). Practical Organic Chemistry (2nd ed.). London: Macmillan and Co., Limited. p. 72.
9. ^ Marvel, C. S.; Jenkins, R. L. (1941). "Methylamine Hydrochloride". Organic Syntheses.; Collective Volume, vol. 1, p. 347
10. ^ Gatterman, Ludwig & Wieland, Heinrich (1937). Laboratory Methods of Organic Chemistry. Edinburgh, UK: R & R Clark, Limited. pp. 157–158.
11. ^ Peter Scott, ed. (13 October 2009). Linker Strategies in Solid-Phase Organic Synthesis. p. 80\. ISBN 9780470749050. "...an unhindered amine such as methylamine"
12. ^ Debacker, Marc G.; Mkadmi, El Bachir; Sauvage, François X.; Lelieur, Jean-Pierre; Wagner, Michael J.; Concepcion, Rosario; Kim, Jineun; McMills, Lauren E. H.; Dye, James L. (1996). "The Lithium−Sodium−Methylamine System: Does a Low-Melting Sodide Become a Liquid Metal?". Journal of the American Chemical Society. 118 (8): 1997. doi:10.1021/ja952634p.
13. ^ Thauer, R. K. (1998). "Biochemistry of methanogenesis: A tribute to Marjory Stephenson:1998 Marjory Stephenson Prize Lecture". Microbiology. 144 (9): 2377–406. doi:10.1099/00221287-144-9-2377. PMID 9782487.
14. ^ Ng, SS; Yue, WW; Oppermann, U; Klose, RJ (February 2009). "Dynamic protein methylation in chromatin biology". Cellular and Molecular Life Sciences. 66 (3): 407–22. doi:10.1007/s00018-008-8303-z. PMC 2794343. PMID 18923809.
15. ^ The Merck Index, 10th Ed. (1983), p.864, Rahway: Merck & Co.
16. ^ CDC - NIOSH Pocket Guide to Chemical Hazards
17. ^ Title 21 Code of Federal Regulations
18. ^ Frank, R. S. (1983). "The Clandestine Drug Laboratory Situation in the United States". Journal of Forensic Sciences. 28 (1): 18–31. doi:10.1520/JFS12235J. PMID 6680736.

* v
* t
* e

Molecules detected in outer space

Molecules|

| Diatomic|

* Aluminium monochloride
* Aluminium monofluoride
* Aluminium(II) oxide
* Argonium
* Carbon monophosphide
* Carbon monosulfide
* Carbon monoxide
* Cyano radical
* Diatomic carbon
* Fluoromethylidynium
* Helium hydride ion
* Hydrogen chloride
* Hydrogen fluoride
* Hydrogen (molecular)
* Hydroxyl radical
* Iron(II) oxide
* Magnesium monohydride
* Methylidyne radical
* Nitric oxide
* Nitrogen (molecular)
* Imidogen
* Sulfur mononitride
* Oxygen (molecular)
* Phosphorus monoxide
* Phosphorus mononitride
* Potassium chloride
* Silicon carbide
* Silicon monoxide
* Silicon monosulfide
* Sodium chloride
* Sodium iodide
* Sulfur monohydride
* Sulfur monoxide
* Titanium(II) oxide

|
|

Triatomic|

* Aluminium(I) hydroxide
* Aluminium isocyanide
* Amino radical
* Carbon dioxide
* Carbonyl sulfide
* CCP radical
* Chloronium
* Diazenylium
* Dicarbon monoxide
* Disilicon carbide
* Ethynyl radical
* Formyl radical
* Hydrogen cyanide (HCN)
* Hydrogen isocyanide (HNC)
* Hydrogen sulfide
* Hydroperoxyl
* Iron cyanide
* Isoformyl
* Magnesium cyanide
* Magnesium isocyanide
* Methylene radical
* N2H+
* Nitrous oxide
* Nitroxyl
* Ozone
* Phosphaethyne
* Potassium cyanide
* Protonated molecular hydrogen
* Sodium cyanide
* Sodium hydroxide
* Silicon carbonitride
* c-Silicon dicarbide
* SiNC
* Sulfur dioxide
* Thioformyl
* Thioxoethenylidene
* Titanium dioxide
* Tricarbon
* Water

Four
atoms|

* Acetylene
* Ammonia
* Cyanic acid
* Cyanoethynyl
* Formaldehyde
* Fulminic acid
* HCCN
* Hydrogen peroxide
* Hydromagnesium isocyanide
* Isocyanic acid
* Isothiocyanic acid
* Ketenyl
* Methylene amidogen
* Methyl radical
* Propynylidyne
* Protonated carbon dioxide
* Protonated hydrogen cyanide
* Silicon tricarbide
* Thioformaldehyde
* Tricarbon monoxide
* Tricarbon monosulfide
* Thiocyanic acid

Five
atoms|

* Ammonium ion
* Butadiynyl
* Carbodiimide
* Cyanamide
* Cyanoacetylene
* Cyanoformaldehyde
* Cyanomethyl
* Cyclopropenylidene
* Formic acid
* Isocyanoacetylene
* Ketene
* Methane
* Methoxy radical
* Methylenimine
* Propadienylidene
* Protonated formaldehyde
* Silane
* Silicon-carbide cluster

Six
atoms|

* Acetonitrile
* Cyanobutadiynyl radical
* E-Cyanomethanimine
* Cyclopropenone
* Diacetylene
* Ethylene
* Formamide
* HC4N
* Ketenimine
* Methanethiol
* Methanol
* Methyl isocyanide
* Pentynylidyne
* Propynal
* Protonated cyanoacetylene

Seven
atoms|

* Acetaldehyde
* Acrylonitrile
* Vinyl cyanide
* Cyanodiacetylene
* Ethylene oxide
* Glycolonitrile
* Hexatriynyl radical
* Methylacetylene
* Methylamine
* Methyl isocyanate
* Vinyl alcohol

Eight
atoms|

* Acetic acid
* Aminoacetonitrile
* Cyanoallene
* Ethanimine
* Glycolaldehyde
* Heptatrienyl radical
* Hexapentaenylidene
* Methylcyanoacetylene
* Methyl formate
* Propenal

Nine
atoms|

* Acetamide
* Cyanohexatriyne
* Cyanotriacetylene
* Dimethyl ether
* Ethanol
* Methyldiacetylene
* Octatetraynyl radical
* Propene
* Propionitrile

Ten
atoms
or more|

* Acetone
* Benzene
* Benzonitrile
* Buckminsterfullerene (C60, C60+, fullerene, buckyball)
* C70 fullerene
* Cyanodecapentayne
* Cyanopentaacetylene
* Cyanotetra-acetylene
* Ethylene glycol
* Ethyl formate
* Methyl acetate
* Methyl-cyano-diacetylene
* Methyltriacetylene
* Propanal
* n-Propyl cyanide
* Pyrimidine

Deuterated
molecules|

* Ammonia
* Ammonium ion
* Formaldehyde
* Formyl radical
* Heavy water
* Hydrogen cyanide
* Hydrogen deuteride
* Hydrogen isocyanide
* Methylacetylene
* N2D+
* Trihydrogen cation

Unconfirmed|

* Anthracene
* Dihydroxyacetone
* Ethyl methyl ether
* Glycine
* Graphene
* Hemolithin (possibly 1st extraterrestrial protein found)
* H2NCO+
* Linear C5
* Naphthalene cation
* Phosphine
* Pyrene
* Silylidine

Related|

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*[CID]: Compound ID
*[EPA]: U.S. Environmental Protection Agency
*[H220]: H220: Extremely flammable gas
*[H315]: H315: Causes skin irritation
*[H318]: H318: Causes serious eye damage
*[H332]: H332: Harmful if inhaled
*[H335]: H335: May cause respiratory irritation
*[P210]: P210: Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
*[P261]: P261: Avoid breathing dust/fume/gas/mist/vapours/spray.
*[P280]: P280: Wear protective gloves/protective clothing/eye protection/face protection.
*[P305+P351+P338]: P305+P351+P338: IF IN EYES: Rinse continuously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.
*[P410+P403]: P410+P403: Protect from sunlight. Store in a well ventilated place.
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