Nitric Acid → 3,4-Dimethyl-2,6-dinitrophenol

Participants

Reaction Conditions

Reaction Steps

A mixture of 630 grams (5 moles/of a 50% aqueous nitric acid and 400 ml dichloromethane were introduced in a two liter flask fitted with a stirrer, a reflex condenser, a dropping funnel and a thermometer. To this stirred mixture was added dropwise a solution of 245 g (2 moles) 3,4-xylenol in 400 ml dichloromethane, during two hours, maintaining the temperature at 20°-25° C. After another hour stirring at the same temperature the reaction mixture was heated to reflux (about 40° C.) until the starting product and the two intermediate products (2-nitro-3,4-xylenol and 4-nitro-3,4-xylenol) have disappeared (followed by GC analysis). This occurs in about three hours. The mixture was cooled to ambient temperature and allowed to separate in two phases. The lower organic phase was separated from the aqueous acidic layer and washed twice with water. Water (400 ml) was added to the organic phase and dichloromethane was removed by distillation. The slurry of the dinitro compound in water was cooled and filtered and dried at 70° C. A product of 93.7%. 2,6-dinitro-3,4-xylenol pure was obtained which was 74.5% of the theoretical yield. After crystallization from ethyl alcohol it has a melting point of 124°-125° C.

Provenance & Evidence