74
3 Combination Tables
Assignment
Range
Comments
Molecular ion
Aliphatic amides: moderate, tendency to
protonate
Aromatic amides: strong
Fragments
Amides: cleavage on both sides of the
carbonyl group followed by loss of CO;
large number of fragments of even mass
Lactams: loss of α-substituent, loss of CO
Rearrangements
Amides: elimination of the amine moiety,
elimination of alkene from the amine or
acid moiety in analogy to esters
[M-18] +·
Lactams
n π*
<220 nm
(log ε 1–2)
Aliphatic amides and lactams
MS
UV