The
Hammick reaction, named after
Dalziel Hammick, is a
chemical reaction described as a thermal
decarboxylation of α-
picolinic (or related)
acids in the presence of
carbonyl compounds to form 2-
pyridyl-carbinols.
Using p-cymene as solvent has been shown to increase yields.
Reaction mechanism
Upon heating α-picolinic acid will spontaneously decarboxylate forming a
zwitterion (
2). In the presence of a strong
electrophile, such as an
aldehyde, the zwitterion will react with the carbonyl faster than protonating. Upon proton transfer the desired carbinol (
4) is formed.
References