CH3NH2\mathrm{CH}_{3} \mathrm{NH}_{2}CH3NH2
(CH3)2NH\left(\mathrm{CH}_{3}\right)_{2} \mathrm{NH}(CH3)2NH
(CH3)3N\left(\mathrm{CH}_{3}\right)_{3} \mathrm{N}(CH3)3N
