N-Butylamine Explained

n-Butylamine is an organic compound (specifically, an amine) with the formula CH3(CH2)3NH2. This colourless liquid is one of the four isomeric amines of butane, the others being sec-butylamine, tert-butylamine, and isobutylamine. It is a liquid having the fishy, ammonia-like odor common to amines. The liquid acquires a yellow color upon storage in air. It is soluble in all organic solvents. Its vapours are heavier than air and it produces toxic oxides of nitrogen during combustion.[1]

Synthesis and reactions

It is produced by the reaction of ammonia and alcohols over alumina:

CH3(CH2)3OH + NH3 → CH3(CH2)3NH2 + H2O

n-Butylamine is a weak base. The pKa of [CH<sub>3</sub>(CH<sub>2</sub>)<sub>3</sub>NH<sub>3</sub>]+ is 10.78.[2]

n-Butylamine exhibits reactions typical of other simple alkyl amines, i.e., alkylation, acylation, condensation with carbonyls.It forms complexes with metal ions, examples being cis- and trans-[PtI<sub>2</sub>(NH<sub>2</sub>Bu)<sub>2</sub>].[3]

Uses

This compound is used as an ingredient in the manufacture of pesticides (such as thiocarbazides), pharmaceuticals, and emulsifiers. It is also a precursor for the manufacture of N,N′-dibutylthiourea, a rubber vulcanization accelerator, and n-butylbenzenesulfonamide, a plasticizer of nylon. It is used in the synthesis of fengabine, the fungicide benomyl, and butamoxane, and the antidiabetic tolbutamide.[4]

Safety

The LD50 to rats through the oral exposure route is 366 mg/kg.[5]

In regards to occupational exposures to n-butylamine, the Occupational Safety and Health Administration and National Institute for Occupational Safety and Health have set occupational exposure limits at a ceiling of 5 ppm (15 mg/m3) for dermal exposure.[6]

Notes and References

  1. Web site: PubChem. Butylamine. 2022-02-15. pubchem.ncbi.nlm.nih.gov. en.
  2. H. K. Hall, Jr.. 1957. J. Am. Chem. Soc.. 79. 5441–5444. Correlation of the Base Strengths of Amines. 20. 10.1021/ja01577a030.
  3. 10.1016/j.ica.2003.10.039. Multinuclear NMR Study and Crystal Structures of Complexes of the Types cis- and trans-Pt(amine)2I2. 2004. Rochon. Fernande D.. Buculei. Viorel. Inorganica Chimica Acta. 357. 8. 2218–2230.
  4. Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke, "Amines, Aliphatic" Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
  5. Web site: n-Butylamine MSDS . 2013-11-12 . https://web.archive.org/web/20131112205047/https://us.vwr.com/stibo/hi_res/8235547.pdf . 2013-11-12 . dead.
  6. https://www.cdc.gov/niosh/npg/npgd0079.html CDC - NIOSH Pocket Guide to Chemical Hazards