A Publication
of Reliable Methods
for the Preparation
of Organic Compounds
Annual Volume
Org. Synth. 1941, 21, 79
DOI: 10.15227/orgsyn.021.0079
[Acetophenone, ω-methoxy-]
Submitted by R. B. Moffett and R. L. Shriner.
Checked by W. E. Bachmann and W. S. Struve.
1. Procedure
A solution of phenylmagnesium bromide is prepared in a 2-l. three-necked flask, fitted with a separatory funnel, reflux condenser, and a mercury-sealed stirrer, from 8.8 g. (0.36 gram atom) of magnesium, 56.5 g. (38 ml., 0.36 mole) of bromobenzene, and a total of 350 ml. of dry ether by the procedure described in Org. Syntheses Coll. Vol. 1, 226 (1941).
To the solution of the Grignard reagent, cooled by an ice-salt bath, a mixture of 21.3 g. (0.3 mole) of methoxyacetonitrile [Org. Syntheses Coll. Vol. 2, 387 (1943)] and 50 ml. of dry ether is slowly added with stirring. The colorless addition product separates at once. After standing at room temperature for 2 hours, the mixture is again cooled and then decomposed by adding, with stirring, 500 ml. of water and cracked ice, and then 100 ml. of cold dilute sulfuric acid (Note 1). When the decomposition is complete (Note 2), the ether layer is separated and the aqueous layer is extracted with a little ether. This ether extract is combined with the ether layer, and the whole is washed with 5% aqueous sodium carbonate solution and then with water. The solution is dried with anhydrous sodium sulfate.
The ether is removed by distillation from a steam bath, and the residue is distilled under diminished pressure. ω-Methoxyacetophenone is a colorless liquid which boils at 118–120° /15 mm. or 228–230° /760 mm. (Note 3). The yield is 32–35 g. (71–78% based on the methoxyacetonitrile).
2. Notes
1. One volume of concentrated sulfuric acid is added to 2 volumes of water, and the mixture is cooled in an ice-salt bath.
2. The two layers should be light yellow in color with only a small amount of solid or tarry material present.
3. The checkers observed a boiling point of 110–112° /9 mm.
3. Discussion
The method described is essentially that of Pratt and Robinson.1 ω-Methoxyacetophenone has also been prepared by chromic acid oxidation of α-phenyl-β-methoxyethanol, which in turn was prepared from styrene oxide.2

References and Notes
  1. Pratt and Robinson, J. Chem. Soc., 1923, 748.
  2. Kaelin, Helv. Chim. Acta, 30, 2132 (1947).

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

sulfuric acid (7664-93-9)

ether (60-29-7)

magnesium (7439-95-4)

sodium carbonate (497-19-8)

sodium sulfate (7757-82-6)

chromic acid (7738-94-5)

bromobenzene (108-86-1)

Phenylmagnesium bromide (100-58-3)

Styrene oxide (96-09-3)

Methoxyacetonitrile (1738-36-9)

Acetophenone, ω-methoxy- (4079-52-1)