Reaction Nitration of a Phenol

After cooling, the distillate is filtered, the o-nitrophenol washed with water, pressed out on a porous plate, and dried in a desiccator. Since it is obtained completely pure, it is unnecessary to subject it to any further process of purification. In order to obtain the non-volatile p-nitrophenol remaining in the flask, the mixture is cooled by immersion in cold water, the water solution is filtered from the undissolved portions, and the filtrate boiled for a quarter-hour with 20 grammes of animal charcoal, the water evaporating being replaced by a fresh quantity. The charcoal is then filtered off and the filtrate allowed to stand in a cool place over night, upon which the p-nitrophenol separates out in long, almost colourless needles. The oil still present in the distillation flask is boiled with a mixture of 1 part by volume of concentrated 

The mon-add phenols of the benzene series are, in contrast to the corresponding hydrocarbons, very easily nitrated. In the nitration of benzene, in order to facilitate the elimination of the water, concentrated sulphuric add must be added whereas the action of concentrated nitric add alone upon phenol is so energetic, that in this case it must be diluted with water. Upon nitrating phenol, the o- and p-nitrophenols are formed simultaneously, the former of which is volatile with steam  

On nitrating the homologues of phenol, the nitro-groups always enter the o- and p-positions to the hydroxyl group, and never the m-position. In order to prepare m-nitrophenol, it is necessary to start from m-nitro-aniline this is diazotised and its diazo-solution boiled with water. 

The nitrophenols behave in all respects like the phenols. But by the entrance of the negative nitro-group, the negative character of the phenol is so strengthened that the nitrophenols not only dissolve in alkalies, but also in the alkali carbonates. 

Experiment Dissolve some o-nitrophenol in a solution of sodium carbonate by warming the scarlet red sodium salt is formed. 

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