An
ethanolic solution of sodium ethoxide is prepared in a
1-l. round-bottomed flask from
15.5 g. (0.67 gram atom) of sodium and
300 ml. of absolute ethanol (Note
1).
One hundred thirty-three grams (0.64 mole) of phenylmethylglycidic ester (p. 727) is added to this solution slowly and with shaking. The flask is then cooled externally to 15°, and 15 ml. of water is slowly added; considerable heat is evolved, and the sodium salt soon begins to separate. After the mixture has stood overnight, the salt is filtered by suction and rinsed with one
50-ml. portion of ethanol and a similar amount of
ether. The dried salt weighs
102–108 g. (
80–85%) and melts at
255–256° with decomposition.
The salt is added to a dilute solution of
hydrochloric acid prepared by mixing 300 ml. of water and
56 ml. of concentrated acid (sp. gr. 1.18); the acid should be contained in a
1-l. flask under a reflux condenser. The mixture is warmed gently, whereupon
carbon dioxide is evolved and an oil separates. The flask is heated on a
steam bath for 1.5 hours, and the oil is then extracted from the cooled mixture with
150 ml. of benzene. The extract is washed once with 200 ml. of water and distilled under reduced pressure, using an
ordinary 500-ml. Claisen flask. The
hydratropaldehyde distils at
90–93°/10 mm. or
73–76°/4 mm. (
oil bath at 120–130°), leaving only a slight residue (3–5 g.). The yield is
56–60 g. (
65–70%) (Note
2) and (Note
3).