3,4-Dimethylphenol

Chemical properties

YELLOW TO BROWNISH CRYSTALLINE MASS

Occurrence

Reported found in coffee, tomato, parmesan and romano cheese, smoked fatty fish, white wine, katsuobushi (dried bonito) and wood vinegar.

The Uses of 3,4-Dimethylphenol

Applications of 3,4-dimethylphenol:

• It can react with ethyl cinnamates in trifluoroacetic acid to form the corresponding dihydrocoumarin derivatives.
• Bromination of 3,4-dimethylphenol using bromine can lead to 6-bromo-3,4-dimethylphenol.
• It can react with 1-fluoro-4-chloromethyl-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoro-borate) (Selectfluor^? F-TEDA-BF₄) to form 4-fluoro-3,4-dimethylcyclohexa-2,5-dienone.

Definition

ChEBI: 3,4-xylenol is a member of the class of phenols that is phenol substituted by methyl groups at positions 3 and 4. It derives from a hydride of an o-xylene.

Aroma threshold values

Detection: 1.2 ppm

General Description

Colorless to light tan crystalline powder or solid. Odor threshold 1.2 mg/L. Taste threshold 0.05 mg/L.

Air & Water Reactions

Hygroscopic. Insoluble in water.

Reactivity Profile

3,4-Dimethylphenol is incompatible with bases, acid chlorides, acid anhydrides, and oxidizing agents. 3,4-Dimethylphenol corrodes steel, brass, copper, and copper alloys.

Fire Hazard

Flash point data for 3,4-Dimethylphenol are not available. 3,4-Dimethylphenol is probably combustible.

Purification Methods

Heat 3,4-xylenol with an equal weight of conc H2SO4 at 103-105o for 2-3hours, then dilute it with four volumes of water, reflux it for 1hour, and either steam distil or extract it repeatedly with diethyl ether after cooling to room temperature. The steam distillate is also extracted and evaporated to dryness. (The purification process depends on the much slower sulfonation of 3,4-dimethylphenol than most of its likely contaminants.). It can also be crystallised from water, hexane or pet ether, and sublimed in a vacuum. [Kester Ind Eng Chem (Anal Ed) 24 770 1932, Bernasconi & Paschalis J Am Chem Soc 108 29691986, Beilstein 6 IV 3099.]