ondensation.
In the balanced chemical equation for the Claisen
condensation, 1 mol of 3-nitrobenzaldehyde (5) is used. In
practice and because of the poor reactivity, a large excess
of the aldehyde 5 was required. Aldehyde 5 could presumably
be recovered by the formation of the bisulfite adduct.
However, the fundamental problem in this chemistry is the
low reactivity of the salt of thiazole 19. With the advent of
the development of ionic liquids as commercial solvents, the
rate enhancements seen in these solvents could very well
facilitate the rate of this condensation. These rate enhancements
have been observed in similar reactions such as a
Claisen rearrangement.34 The condensation of equimolar