[CONTRIBUTION FROM THEIKSTITUTE
O F PAPER
CHEMISTRY]
CONIDEWDRIN FROM WESTERN HEMLOCK SULFITE WASTE LIQUOR' IRWIIi .4. PEARL Received February Y, 10.55
Recently in these laboratories Brauns (1, 2) obtained conidendrin in substantial yield during the isolation of native lignin from western hemlock (Tsugar keterophylZa). Because no conidendrin was obtained during the analogous isolation of native lignin from black spruce (Picea muriuna) (3) and because Picea mariana waa one of the spruces whose sulfite waste liquor yielded conidendrin (4), it seemed very probable that the sulfite waste liquor from western hemlock should yield relatively large amounts of conidendrin upon ether extraction. This was confirmed by experiment. Exactly 45oL) ml. of digester strength western hemlock sulfite waste liquor' (containing 92.6 gr:tms/liter of total solids) was placed in an airagitated Pearl continuous liquid-liquid extractor ( 5 ) and waa extracted with ether for 15 hours. White crystals separated from the 600 ml. of ether used as the solvent. These were filtered and washed with ether. A yield of 2.26 g. of conidendrin melting at 238", resolidifying, and finally melting a t 255-256" was obtained. Anal. Calc'd for CpDEIpoOs: CHaO, 17.40. Found: CHaO, 17.34, 17.34. The ethereal filtrate was dried with anhydrous sodium sulfate and distilled on the steambath, finally under reduced pressure. A gray powder weighing 3.91 g. was obtained as a residue. This powder was treated with 100 ail. of cold anhydrous ethanol, shaken well, and filtered. White crystals of conidendrin melting at 238"/256256" and weighing 1.27 g. were obtained. The alcoholic solution was diluted with 10 volumes of water and boiled t o remove the ethanol. The cloudy solution was cleared with a little sodium hydroxide solution and then neutralized with dilute sulfuric acid. More sulfuric acid was added to make the resulting solution 5% with sulfuric acid, and 1,he mixture was boiled under reflux for 3 hours and allowed to cool. A white crystalline precipitate and a brown tar separated. The crystalline precipitate of conidendrin weighed 1.43 g. and melted a t 232"/248-255". The brown t a r weighed 1.02 g. and was not further characterized. The total yield of conidendrin was 4.96 g. and amounted t o 1.1 g. per liter ol digester strength sulfite waste liquor. This yield is considerably more than the 200 mg. per liter from Norway spruce (Picea ezcelsa) waste liquor reported by Holmberg (6), who extracted the waste liquor by shaking in a separatory funnel. The efficiency of the continuous extractor, as compared with the manual method of extraction, might be in part responsible for this great difference in yield. Although the cooking data for the sample of sulfite waste liquor used was not known, an attempt to correlate the conidendrin yield with the original wood was made. Assuming that, in the sulfite pulping operation, one ton of sulfite waste liquor solids is produced for every ton of pulp and that the pulp yield is Myo,then one liter of this digester strength liquor is equivalent to 184 grams of western hemlock wood. The yield of 1.1 g. per liter amounts to 0.6% on the basis of the wood. This yield from western hemlock sulfite waste liquor, compared with the 0.15% obtained by solvent extraction of western hemlock wood ~
-
This work was carried out as a part of a fundamental research on the color principle of western hemlock for the Crown Zellerbach Corporation; the Institute acknowledges permission to publish these results. 2 The sulfite waste liquor was a commercial product kindly furnished by the Crown Zellerbach Corporation, Camas, Washington. 219 1
220
IRWIN -4. PEARL
(Z),concurs with the results ob-sinetl by Erdtmann (4), who noted that the yield of conidendrin from spruce waste liquor was considerably more than that obtainable from the original wood by solvent extraction.
Conidendrin was found to possess a very peculiar melting point. A review of the literature verified this finding. Holmberg (6) noted that the compound melted above 250" after sintering and coloring, but recorded no exact temperatures. Kawamura (7), who isolated conidendrin from Japanese hemlock (Tsuga sieboldii), reported the compound to melt at 235-237" with slow evolution of carbon dioxide, resolidifying and remelting a t 255". Emde and Schartner (8) reported conidendrin extracted from Norway spruce or from Japanese hemlock to be identical with Holmberg's product from Norway spruce sulfite liquor and to melt at 255". Keimatsu, Ishiguro, and Yaniamoto (9) obtained conidendrin melting at 254-255" from Japaflese hemlock. Briggs and Peak (10) isolated conidendrin from "matai" (Podocurpus spicutus) and described the peculiar melting point of the compound. They reported that with slow heating conidendrin melts at 254-255" after shrinking a t 236". With quick heating it decomposes at 236" and melts at 254". With rapid heating it melts at 232". Erdtmann (4) extracted sulfite waste liquors from a large number of conifers and obtained conidendrin from 7 out of 14 spruces, 4 out of 4 hemlocks (not including western hemlock), and one out of 7 firs. Erdtmann did not record a melting point for conidendrin, but noted that the melting point of conidendrin wag insufficiently sharp for comparison purposes. It is interesting to note that a sample of conidendrin isolated by Brauns (2) and recrystallized from 9576 ethanol melted sharply at 255" without previous melting. However, upon recrystallization from absolute ethanol, heavy crystals melting a t 238"/255-256" were obtained. A mixed melting point with the product isolated by ether extraction of western hemlock sulfite liquor was not depressed. The conidendrin from waste liquor, upon recrystallization from acetone or water, yielded crystals melting at 238"/255-256". No carbon dioxide evolution, as reported by Kawamura (7), could be observed. Recrystallization from benzene gave a white crystalline powder melting at 255-256" without previous melting. Recrystallization from ethanol gave either of the two forms depending upon conditions. Fast heating to boiling and filtering gave fine fluffy needles melting a t 255-256" without previous melting. Continued heating a t the boiling point before filtering yielded heavy crystals melting a t 238"/255-256". The fluffy needles are very insoluble in cold ethanol, whereas the heavy crystals separated only after considerable concentration and cooling. Melting a t 238" and resolidifying at 240-245" changed the crystalline form of the 238"/255 -256" crystals to long fine needles. The specific rotations of both melting forms were identical-[c~1','-53.7" (c = 2.125 in acetone). Acetates of both forms were prepared according to Holmberg (6) and both melted at 221-222", mixed m.p. 221-222". The data of this experiment indicate that the sulfite waste liquor from western hemlock offers an unlimited readily available source of large amounts of relatively pure conidendrin for further research.
CONIDENDRIN FROM HEMLOCK SULFITE LIQUOR
221
Studies on the reactions of conidendria and on its isolation from pulping liquors from a large number of woods are in progress. APPLETON,Wrs. REFEREXCES (1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
BRAUNS,J . Org. Chem., 10, 216 (1945). BRAUNS, J . Org. Chem., 10, 216 (1945). BRATJNS, J . Am. Chem. SOC.,61, 2120 (1939). ERDTMAN, Svensk Papperstidn., 47, 155 (1944). PEARL,Ind. Eng. Chem., Anal. Ed., 16, 62 (1944). HOLMBERG, B e . , 64,2389 (1921). KAWAMURA, Bull. Imp. Forestry Expt. Sta. Tokyo, 31,73 (1932). EMDE AND SCHARTNER, Helv. Chim. Actu, 18, 344 (1935). KEIMATSU, ISHIGURO, AND YAMAMOTO, J. Pharm. SOC.Japan, 66,381 (1935) BRIGGS AND PEAK,J . Chem. Soc., 724 (1936).
