CH3Br + NH3 —(t°)→ [CH3NH3]+Br-
[CH3NH3]+Br– + NH3 —(t°)→ CH3NH2↑ + NH4Br
CH3NH2 + CH3Br —(t°)→ [(CH3)2NH2] + Br-
[(CH3)2NH2]+Br– + NH3 —(t°)→ (CH3)2NH + NH4Br
(CH3)2NH + CH3Br —(t°)→ [(CH3)3NH] + Br-
[(CH3)3NH]+Br– + NH3 —(t°)→ (CH3)3N + NH4Br
(CH3)3N + HBr → [(CH3)3NH] + Br-