Potassium Hydroxide → 2,3,5,6-Tetrabromo-p-xylene-alpha,alpha'-diol
Reaction equation
[OH-].[K+].C([O:6][CH2:7][C:8]1[C:13]([Br:14])=[C:12]([Br:15])[C:11]([CH2:16][O:17]C(=O)C)=[C:10]([Br:21])[C:9]=1[Br:22])(=O)C>O.O1CCOCC1>[Br:14][C:13]1[C:12]([Br:15])=[C:11]([CH2:16][OH:17])[C:10]([Br:21])=[C:9]([Br:22])[C:8]=1[CH2:7][OH:6]Participants
Procedure
A solution of potassium hydroxide, 20 parts, in water, 50 parts, was added dropwise to a refluxing solution of 20 parts 2,3,5,6-tetrabromo-p-xylene-α,α'-diol diacetate, prepared as in Example III above, in p-dioxane, 200 parts. After 2 hours at reflux the mixture was cooled somewhat and the bulk of the dioxane-water removed by a rotary evaporator. Water was added to the semi-solid residue, the precipitate filtered, washed with water and air dried to give crude diol, 16.7 parts. Recrystalization from dioxane-water gave 12.2 parts 2,3,5,6-tetrabromo-p-xylene-α,α'-diol, melting at 262°-263.5° C. A second crop, 3.95 parts, melted at 260-262° C. A third crop, 0.4 parts, melted at 225°-245° C. Combining the first two crops gives a yield of 96 percent. Analysis showed the following results: Percent bromine calculated -- 70.5; found -- 71.5.
Workup
- temperatureAfter 2 hours at reflux the mixture
- temperaturewas cooled somewhat
- customthe bulk of the dioxane-water removed by a rotary evaporator
- additionWater was added to the semi-solid residue
- filtrationthe precipitate filtered
- washwashed with water and air
- customdried
- customto give crude diol, 16.7 parts
- customRecrystalization from dioxane-water
Sources & evidence
- ORD record
- ord-db22fb7e53504e25b5f794d697e77e3f
- Source dataset
- uspto-grants-1978_08
- Patent number
- US04107104
Reaction notes
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