Org. Synth. 1944, 24, 82
DOI: 10.15227/orgsyn.024.0082
PHENYLMETHYLGLYCIDIC ESTER
[Hydrocinnamic acid, α,β-epoxy-β-methyl-, ethyl ester]
Submitted by C. F. H. Allen and J. VanAllan.
Checked by Nathan L. Drake and Carl Blumenstein.
1. Procedure
To a mixture of
120 g. (118.5 ml., 1 mole) of acetophenone (Note 1),
123 g. (109 ml., 1 mole) of ethyl chloroacetate, and
200 ml. of dry benzene in a
1-l. three-necked round-bottomed flask, fitted with a stirrer and low-temperature thermometer, is added, over a period of 2 hours,
47.2 g. (1.2 moles) of finely pulverized sodium amide. The temperature is kept at 15–20° by external cooling
(Note 2). After the addition has been completed, the mixture is stirred for 2 hours at room temperature, and the reddish mixture is poured upon 700 g. of cracked ice, with hand stirring. The organic layer is separated and the aqueous layer extracted once with
200 ml. of benzene. The combined
benzene solutions are washed with three 300-ml. portions of water, the last one containing
10 ml. of acetic acid. The
benzene solution is dried over
25 g. of anhydrous sodium sulfate, filtered, the drying agent rinsed with a little dry
benzene, and, after removal of the solvent, the residue is fractionated under reduced pressure, using a
modified Claisen flask. The fraction boiling at
107–113°/3 mm. is collected separately and used for the preparation of
hydratropaldehyde (p. 733). Redistillation yields a product which boils at
111–114°/3 mm. (Note 3). The yield is
128–132 g. (
62–64%)
(Note 4).
2. Notes
1.
The practical grades of ketone and ester were used.
2.
The reaction is strongly exothermic, and much
ammonia is evolved.
3.
Other boiling points are
272–275°/760 mm. with decomposition;
153–159°/20 mm.; and
147–149°/12 mm.
4.
There are several side reactions which reduce the yield. There are always unchanged ketone and ester in the low-boiling fraction, and also some chlorocinnamic ester.
3. Discussion
This is an example of a general reaction by which haloesters are condensed with ketones by means of
sodium,
1 sodium ethoxide,
2,3 or
sodium amide.
4,5,6
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
Phenylmethylglycidic ester
acetic acid (64-19-7)
ammonia (7664-41-7)
Benzene (71-43-2)
sodium sulfate (7757-82-6)
Acetophenone (98-86-2)
sodium (13966-32-0)
sodium ethoxide (141-52-6)
Ethyl chloroacetate (105-39-5)
sodium amide (7782-92-5)
hydratropaldehyde (93-53-8)
Hydrocinnamic acid, α,β-epoxy-β-methyl-, ethyl ester (77-83-8)
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