Water → 2,3,5,6-Tetramethyl-1,4-benzenedicarboxylic acid
Reaction equation
[CH3:1][C:2]1[C:7]([CH3:8])=[C:6]([CH2:9][OH:10])[C:5]([CH3:11])=[C:4]([CH3:12])[C:3]=1[CH2:13][OH:14].S(=O)(=O)(O)[OH:16].[OH2:20]>CC(C)=O.[O-2].[Cr+6].[O-2].[O-2]>[CH3:12][C:4]1[C:5]([CH3:11])=[C:6]([C:9]([OH:16])=[O:10])[C:7]([CH3:8])=[C:2]([CH3:1])[C:3]=1[C:13]([OH:14])=[O:20]Participants
Conditions
- Temperature
- 0 °C
Procedure
2,3,5,6-Tetramethyl-p-xylene-α,α'-diol (5.0 g, 26 mmol) was suspended in 250 mL of distilled acetone, and cooled to 0° C. To a separate solution of chromium (VI) oxide (14.15 g, 0.14 ml) in 50 mL of water was dropwise added concentrated sulfuric acid (14.5 mL, 0.26 mol) at 0° C. during 45 minutes. This mixture was then added dropwise during 30 minutes to the acetone solution, with stirring at 0° C. The mixture was stirred vigorously at 0° C. for 1 hour, then at room temperature for 18 hours. The reaction mixture was concentrated by rotary evaporation, and 1 NHCl was added to attain pH 1. The product was precipitated by cooling, then was filtered, washed with water (3×) and diethyl ether (3×), and dried at high vacuum to afford 4.55 g (80%) of the product (HOOC--C6 (CH3)4 --COOH) as a white solid, m.p. >300° C.
Workup
- stirringThe mixture was stirred vigorously at 0° C. for 1 hour
- concentrationThe reaction mixture was concentrated by rotary evaporation, and 1 NHCl
- additionwas added
- customThe product was precipitated
- temperatureby cooling
- filtrationwas filtered
- washwashed with water (3×) and diethyl ether (3×)
- customdried at high vacuum
Sources & evidence
- ORD record
- ord-6becdaf5a0664db08c43ec074284ed98
- Source dataset
- uspto-grants-1991_10
- Patent number
- US05055451
Reaction notes
Loading…