Phosphoric acid Amphetamine phosphate

When the entire quantity of the phosphoric acid has thus been added, agitation of the mixture is continued for about a half-hour or more to insure complete conversion. The precipitate is then allowed to settle, the supernatant liquid is drawn off, and the residue is filtered. The precipitate thus separated may, if desired, be washed with acetone and is then dried by evaporation to constant weight. It forms a fine, white, impalpable powder consisting of pure monobasic amphetamine phosphate. 

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