Organic Syntheses, CV 4, 520
Submitted by N. M. Cullinane, S. J. Chard, and C. W. C. Dawkins
1.
Checked by T. L. Cairns and D. C. England.
1. Procedure
A solution of
100 g. (1.06 moles) of phenol in
1 l. of methanol is allowed to drop at a rate of 110 ml. per hour (Note
1) over an
activated alumina catalyst (Note
2) heated to 530° (Note
3). The exit from the hot tube is attached to a
receiver arranged to lead by-product gases to an
efficient hood (Note
4). After addition of the
methanol solution is finished, the pale yellow product is transferred to a
Büchner funnel and washed with
methanol. The yield of crude product melting at
135–145° is
112–115 g. (
65–67%). Recrystallization from
ethanol (50 g. in 650 ml.) gives
85% recovery or from
benzene (50 g. in 130 ml.) gives
60% recovery of colorless
hexamethylbenzene, m.p.
165–166°.
2. Notes
1. The submitters used a rate of 250 ml. per hour with a
2-in.-diameter tube, 16 in. long, packed with 300 g. of alumina, and a temperature in the catalyst bed about 370–380°. The checkers used
34 g. of alumina packed in a 7/8-in.-diameter tube 13 in. long.
2. The submitters used 4- to 8-mesh alumina from Peter Spence and Sons, Widnes, Lancashire, England. The checkers used 8- to 14-mesh Alorco H-41 obtained from the Aluminum Company of America, 1200 Alcoa Building, Pittsburgh 19, Pennsylvania.
3. Automatically controlling the outside of the catalyst tube to 370–400° gives a hot spot in the catalyst bed of 530° at the rate specified in equipment used by the checkers.
3. Discussion
Copyright © 1921-2002, Organic Syntheses, Inc. All Rights Reserved