Page 231 - Chemical and process design handbook

Speight_Part II_C 11/7/01 3:08 PM Page 2.171

CINNAMIC ALDEHYDE

o
Cinnamic aldehyde (boiling point: 253 C with decomposition, melting
o
point: 7.5 C, density: 1.0497) has a cinnamon odor, hence the name. As
it oxidizes in air to cinnamic acid, it should be protected from oxidation.
Although this aldehyde is obtained from Chinese cassia oils, it is synthe-
sized by action of alkali upon a mixture of benzaldehyde and acetaldehyde
(Fig. 1).

C H CH=O + CH CH=O → C H CH=CHCH=O
6 5 3 6 5
This and most other products for fragrances must be purified by, for example,
vacuum fractionation.

Benzaldehyde,
water, solvent,
catalyst Water

Acetaldehyde
Light
ends
Reactor Reactor Reactor Distillation

Waste Waste
Cinnamic aldehyde
FIGURE 1 Manufacture of cinnamic aldehyde.

2.171