why does the N on ammino acid SERENE have 3 CH3 and not 4 ? isn't it supposed to make a quaternary ammonium salt with excess haloalkane, im so confused
serene is the one theyre asking for, in the answer the serene has a positive N and 3CH3 gorups attached
1st substititution 1 lone pair on N attacks delta positive carbon on bromomethane you get (CH3)RN+H2 RNH2 accepts one of the H on (CH3)RN+H2, electrons from the N-H bond go to the N and neutralise positive charge you get (CH3)RNH
2nd substitution 1 lone pair on N attacks delta positive carbon on bromomethane you get (CH3)2RN+H
RNH2 accepts one of the H on (CH3)2RN+H, electrons from the N-H bond go to the N and neutralise positive charge you get RN(CH3)2
3rd substitution 1 lone pair on N attacks delta positive carbon on bromomethane you get RN+(CH3)3
RNH2 cannot accept any more H. So reaction stops here. You actually only get a tertiary ammonium salt
thank u, so is the same idea used if another amino acid was used, will amino acids always form only tertiary ammonium salts