Checked by Roger Adams and C. G. Gauerke.
1. Procedure
A mixture of
1 l. of benzene,
600 g. (529 cc., 6.1 moles) of 2-furylcarbinol (p. 276) (Note
1),
225 g. (2.7 moles) of fused powdered sodium acetate, and
650 g. (602 cc., 6.4 moles) of a good grade of acetic anhydride are placed in a
5-l. round-bottomed flask (Note
2) fitted with a
mechanical stirrer and a
reflux condenser provided with a
calcium chloride tube. The flask is heated on a
steam bath (Note
1) for four hours with stirring to prevent caking of the
sodium acetate.
The reaction mixture is allowed to cool and is poured into 4 l. of cold water (Note
3). The upper layer is separated and allowed to stand for two hours over about
500 cc. of 5 per cent sodium carbonate solution with frequent shaking or mechanical stirring. This decomposes any excess of
acetic anhydride. It is finally washed with about 3 l. of water. The
benzene solution is distilled under ordinary pressure to remove the
benzene (800–900 cc. is recovered). The
2-furylmethyl acetate is distilled under diminished pressure, b.p.
69–70°/7 mm. The yield is
750–800 g. (
87–93 per cent of the theoretical amount) (Note
4).
2. Notes
1. If the water-insoluble form of the alcohol
(p. 278) is used, the mixture should be allowed to stand under a reflux condenser for about two hours before it is heated. During this period a certain amount of heat is evolved, and sometimes it is sufficient to cause the
benzene to boil vigorously, thus making cooling necessary. After it has stood the required time, the mixture is refluxed as described above.
2. If a
two- or three-necked flask is available it can be used to advantage.
3. The washing can best be done in a large separatory apparatus prepared by cutting the bottom out of an
18-l. (5-gallon) glass carboy and wiring into its neck a piece of glass tubing carrying a
rubber tube and
pinch clamp. The inverted carboy forms a useful
separatory funnel of large capacity.
4. Saponification of the product with standard
potassium hydroxide shows
93–94 per cent ester. It contains some
furfuryl alcohol, the removal of which by fractional distillation is difficult, because the boiling points of the alcohol (
169°/752 mm.) and the ester (
175°/764 mm.) are so close together.
Furfuryl acetate darkens on standing. It may be redistilled with little loss to give an almost colorless product.
3. Discussion
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