Patent ID: 8197870

Claim:
A process for extracting a neutral organic compound from birch bark, comprising: physically processing birch bark comprising one or more of pelletizing the bark, baling the bark, pucking the bark, or compressing the bark to a more dense form than prior to the processing; contacting the bark with a mixture of an alkaline aqueous solution and a water-soluble organic solvent, wherein the step of contacting comprises heating the bark in the mixture and optionally comprises soaking the bark in the mixture; separating undissolved bark portions, optionally by filtering, and optionally further comprising a step of washing of the undissolved portions of the bark with the water-soluble organic solvent; removing substantially all of the water-soluble organic solvent; adding a water-insoluble solvent, wherein the water-insoluble solvent comprises hexane, heptane, octane, nonane, toluene, xylenes, benzene, or a combination thereof; removing water to obtain a dried water-insoluble solvent extract; separating insoluble material, and optionally, in the same step separating of undissolved bark portions, wherein the separating is optionally carried out by filtering; removing a major portion of the water-insoluble solvent to yield a concentrated extract; and recovering the neutral organic compound from the concentrated extract.