Picramic add

Procedure Dissolve 100 grams of ammonium picramate in 1000 milliliters of cold water while stirring the water (if some of the ammonium picramate fails to dissolve, add an additional 400 milliliters of water). To this solution, add drop wise, over a period of ten minutes, 26.8 grams of glacial acetic acid. After the addition of the glacial acetic acid, filter-off the product, wash with 400 milliliters of cold water, and then dry in an oven at 80 Celsius for 1 hour. 

If the substance being reduced contains an acid group, this may serve to neutralize the alkali formed (see, e.g., the preparation of picramic acid, page 152). It may also be beneficial to add MeS04 to the reduction mixture. Since s compound reacts with the NaOH formed to precipitate very slightly soluble Mg(OH)2, the solution can become only weakly alkaline. 

Nitration of phenol in sulfuric acid produces 2,4,6-trinitrophenol (picric add). Picric acid is used predominantly as an intermediate in the production of picramic acid, a raw material for dyestuffs picric acid has lost its earlier importance as an explosive. 

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