Organic Syntheses, CV 2, 622
Submitted by J. S. Buck and W. S. Ide.
Checked by John R. Johnson and E. Amstutz.
1. Procedure
In a
1-l. round-bottomed flask,
83 g. (0.5 mole) of veratraldehyde (p. 619) is dissolved in
200 cc. of warm 95 per cent alcohol, and a warm solution of
42 g. (0.6 mole) of hydroxylamine hydrochloride (Org. Syn. Coll. Vol. I, 1941, 318) in 50 cc. of water is added. The two solutions are mixed thoroughly, and a solution of
30 g. (0.75 mole) of sodium hydroxide in 40 cc. of water is introduced. After the mixture has stood for two and one-half hours at room temperature, 250 g. of crushed ice is added and the solution is saturated with
carbon dioxide. This causes the separation of the aldoxime as an oil which solidifies on standing overnight in an ice chest (Note
1). The crystalline oxime is filtered with suction, washed thoroughly with water, and allowed to dry in the air. The yield of oxime is
88–89 g. (
97–98 per cent of the theoretical amount).
The
veratraldoxime is placed with
100 g. of acetic anhydride (94–96 per cent) in a
300-cc. round-bottomed flask provided with a
ground-glass air condenser (Note
2), and heated cautiously. A vigorous reaction takes place, and when this occurs the flame is removed. After the reaction has subsided the solution is boiled gently for twenty minutes and then poured carefully, with stirring, into 300 cc. of cold water. The stirring is continued, and on cooling the nitrile separates in small, almost colorless crystals, which are filtered and dried in the air. The
veratronitrile thus obtained is quite pure; it weighs
57–62 g. (
70–76 per cent of the theoretical amount, based upon the
veratraldehyde), and melts at
66–67°.
2. Notes
1. Occasionally the oxime does not solidify after standing overnight. If this happens it is advisable to separate the oily layer, treat with crushed ice, and induce crystallization by scratching. If a seed crystal of the oxime is available no difficulty is experienced.
2. If a cork or
rubber stopper is used the product is likely to be colored.
3. Discussion
This preparation is referenced from:
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