[kennykwong]

i am quite confused with the nomenclature of amine especially when NH2 just connected to hydrocarbon (alkane) only. For example, methylpropananime or aminobutane. which one is follow the IUPAC nomenclature system?
Thanks

[Dan]

It depends on the structure - there are 4 isomers or butanamine. You have not provided enough information - include locant numbers.

[kennykwong]

how about the amine with formula CH3C(CH3)CH2NH2 and CH3C(NH2)CH2CH3

[Dan]

What do you think and why?

You must show you have attempted the question, this is a Forum Rule.

[kennykwong]

i think for CH₃C(CH₃)CH₂NH₂ is methylpropanamine and i am not sure for the another one. however, according to my revision book the second one is started with the amino prefix. and according to IUPAC website they say the amino is used when NH₂ is not principal group, so does it mean that NH₂ might be not a principal group even there are just alkane group combine with it like the 2nd case just now?

[Dan]

Methylpropanamine is still ambiguous. You need locant numbers - e.g. 2-methylpropan-2-amine is this:



If there is only an amine and an alkane present, the amine is the principal group. "Aminobutane" is commonly used, but it is not the IUPAC recommended name - "butanamine" is the IUPAC name - e.g. the following molecule is propan-2-amine by IUPAC convention (not 2-aminopropane).

[kennykwong]

Oh i see, thanks