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]
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]
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]
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]