&MARSHALL KULKAAND HAROLD HIEBERT
1180
repeated, leaving a viscous tar (D) (25.3 g.). Concentration of the combined petroleum ether solutions (Y’, Y”, Y’”) (water-bath 50-60”), followed by removal of the last traces of solvent under reduced pressure ( N O ) , left a residue of light-colored petroleum ether-soluble ethanolysis oils (43.3 g.) (E). Solvent Group Fractionation of the Petroleum Ethersoluble Ethanolysis Oils.-The petroleum ether-soluble oils (43.3 9.) were dissolved in benzene (300 cc.) and the solution extracted successively with (a) eight 30-cc. portions of aqueous sodium bisulfite (20%), and the bisulfite extract (F) back-extracted with two 30-cc. portions of benzene which were then combined with the main benzene solution; (b) three 30-cc. portions of 8% sodium bicarbonate (back-extraction as in (a)); and (c) eight 35-cc. portions of 5% sodium hydroxide (back-extraction as in (a)). (Each of the sodium hydroxide extracts was neutralized immediately after extraction.) The oil remaining in the benzene solution was the “neutral fraction.” Each of the extracted fractions (a), (b) and (c) was then acidified (Congo red) with dilute sulfuric acid. In the case of the bisulfite extract the sulfur dioxide was removed after acidification by use of a carhon dioxide bubbler under reduced pressure. The various acidified solution-, were ex-
____-___ [CONTRIBUTION FROM
THE
Vol. 65
tracted with benzene, the benzene solutions dried with sodium sulfate and the solvent removed under reduced pressure yielding a bisulfite-soluble fraction (10.3 g.) ; bicarbonate-soluble fraction (0.4 g ~;) alkali-soluble (“phenol”, fraction (24.7 g.) and “neutral” fraction (5.4 g.).
Acknowledgments.-The authors wish t o thank Mr. M. Kulka, Mr. H. E. Fisher and Mr. S. B. Baker for their assistance in carrying out part of the procedure and t o express their appreciation of the financial assistance accorded them by the Canadian Pulp and Paper Association and Canadian Industries Limited. Summary An improved method for the extraction and isolation of the water-soluble ethanolysis products from maple wood is given. These are free from resinous materials and represent completely distillable (monomeric) oils, amounting to a total of 29% of the original Klason lignin, MONTREAL, CANADA
KECRIVEDFEBRUARY 23, 1043
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DIVISION O F INDUSTRIAL
AND
CELLULOSE CHEMISTRY, MCGILLUNIVERSITY]
Studies on Lignin and Related Compounds. LXVII. Isolation and Identification of 1- (rl-Hydroxy-3,5-dimethoxyphenyl)-Z-propanone and 1-(4-Hydroxy-3-methoxyphenyl)-2 -propanone from Map1e Wood Ethanolys is Pro ducts. Metab olic Changes in Lower and Higher Plants BY MARSHALL KULKAAND HAROLD HIBBERT In a previous communication’ the isolation of and t o settle the question of the presence or abl-(4-hydroxy-3-methoxyphenyl)-1,2-propanedionesence of vanillin and syringaldehyde. The pres(I) and 1- (4-hydroxy-3,5-dimethoxyphenyl) - 1,2- ence of the two latter compounds has been estabpropanedione (11) from the carbonyl components lished definitely and in addition two hitherto unof the water-soluble ethanolysis products of maple known carbonyl components, namely, 1-(l-hywood was reported. I t was indicated that about droxy-3-methoxyphenyl)-2-propanone(111)and 1 30% of the bisulfite-soluble fraction of the water- (4 - hydroxy - 8,s - dimethoxyphenyl) - 2 - prosoluble maple ethanolysis oils corresponding to panone (IV), were isolated and their structures 1.3% of the Klason lignin was still unidentified, established by direct synthesis. The ethanolysis procedure used was that deand that vanilli; and syringaldehyde could not be detected, although their presence had been rz- scribed in the preceding communication4 in which ported ear1ier.l In a later communicationdi t was various modifications have been introduced reshown that the amounts of vanillin and 1-(4- sulting in more complete ‘group classification” hydroxy-3-methoxyphenyl)- 1,&propanedione var- with consequent increase in purity in products. ied in different spruce ethanolysis experiments, The bisulfite-soluble fraction isolated by this technique was used in this investigation. the former actually being absent in certain runs. Separation and Identification of the BisulfiteThe purpose of this investigation was to identify soluble Carbonyl Components.-The dicarbonyl the unknown carbonyl components present in the compounds present in the bisulfite fraction were bisulfite fraction of the maple ethanolysis oils, separated quantitatively by precipitation as their (1) Kulka, Hawkins and Hibbert, Tms JOUXNAL, 68, 2371 (1941). i
(21 i’yle Mrickrnsn and Hibbert, rbrd , 61, 2198 (1039) (3) I i i x a k w ~ n .H-wkina and Hrhhert, rbtd , 62. 2149 (1940)
(4) We-t. blucCragor, Lexi, Evuus and Hibbert. r b i d . , 66, 1176
(lvra)
METABOLIC CHANGES IN LOWER AND HIGHERPLANTS
June, 1943
llSl
tained. The aldehydes were separated from the oximes by extraction with sodium bisulfite solution and from each other by fractional distillation. Hydrolysis of the oximes was accomplished with 7 N sulfuric acid, and the resulting free carbonyl compounds separated by fractional distillation in the Cooke-Bower type of micro-fractionating column developed in these laboratories.: This column is vacuum-jacketed, 14 CHART I cm. long and has an efficiency of Bisulfite-soluble Fraction seven plates. The details of the I treated with (NH~OH)YH~SO., separation and isolation are sumNE12 and NaOAc marized in Chart I and the results of several ethanolysis runs shown 1 in Table I. Filtrate (B) Precipitated nickel salts of the I The analysis and molecular extracted with benzene diketones (A) weight determination of 1-(4-hyI Syringaldehyde, vanillin &oxy - 3,5 - dimethoxyphenyl) -2and the oximes (C) propanone (IV) and the preparaI extracted with tion and analysis of its semicarNaHSOIl bazone established its empirical I formula as CllH1404, and showed the presence of one carbonyl Bisulfite-insoluble Bisulfitk-soluble oximes (E) aldehydes (D) group, Oxidation of the methI I ylated product with potassium 7 N H2S04 dil. H&04 followed by extraction I permanganate yielded 3,4,5-triDesoxybenzoins I methoxybenzoic acid, indicating fractional I fractional distillation the aromatic nucleus to be either distillation ! 4- hydroxy- 3,5-dimethoxyphenylI I (IV)or 3-hydroxy-4,5-dimethoxyI I I \ I 7 I 1-(4-Hydioxy-3,5- phenyL(VI1). Treatment with Vanillin Syringaldehyde l-(CHydroxy-3methoxyphenyl) - dimet hoxy phenyl) - alkaline iodine yielded iodoform, 2-propanone 1- (4-Hydroxy-3,fj-dimethoxy2-propanone thus indicating the presence of a pheny1)d-propanone methyl ketone in the side chain. Two formulas (IV) and (VII) TABLE I thus called for consideration but its identity with ANALYSISOF THE BISULFITE-SOLUBLE FRACTION the synthetic product (IV) definitely established Amount of dry maple wood meal taken for each experiits structure. ment was 1000 g. containing 203 g. of Klason lignin
nickel glyoxime salts.' Under the conditions employed, it was found that vanillin and syringaldehyde did not form oximes with hydroxylamine, while the unknown carbonyl derivatives reacted readily, so that, after removal of the insoluble nickel salts and extraction of the filtrate with benzene, a mixture of the two aldehydes and the oximes of the new carbonyl derivatives was ob-
I
3
I
Ethanolysis experiment 1 2 3
Total bisulfite-soluble oils, g. 10.30 11.47 10.79 Nickel glyoxime salts found, g. 6.23 6 . 5 8 G.20 Mixt. of the diketones (calcd.), g. 4.90 5.16 4.89 2.42 2.54 2 . 4 1 Klason lignin, % Syringaldehyde (pure), found, g. 0 . 7 3 1.30 0.67 .33 Klason lignin, $& .36 0.64 .23 .14 Vanillin (pure), found, g. .08 .ll .07 I200 >I17 .06 . . ...... Fraction 1was recrystallized from water; m. p. 80-81 O ; no m. p. depression when mixed with vanillin. Fractions 2, 3 and 4 were each recrystallized from water; m. p . 111-112°; no m. p. depression when mixed with syringaldehyde. a
(c) Isolation of 1-(4-Hydroxy-3-methoxyphenyl)-2propanone (III)and 1-(4-Hydroxy-3,5-dirnethoxyphenyl) 2-propanone (N).-The benzene solution containing the oximes (E) was filtered to remove the tar, then dried and the solvent removed. The residue (2.30 g.) was treated with 7 N sulfuric acid (150 cc.) at room temperature for twenty-four hours followed by four hours a t 40". The acid solution was extracted with benzene, the benzene extract dried over sodium sulfate and sodium bicarbonate, and the solvent removed by distillation. The residue (1.56 g.) was distilled from a Spath bulb and the distillate (1.23 g.) fractionally distilled in the Cooke-Bower column.
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1184
MARSHALL
KULKAAND HAROLD HI3BERT
Vol. G5
with dilute sulfuric acid and with water, then dried; yield, S.4 g. (85%); m. p. 101-102"; recrystallized from ethanol and from ether; m. p. 103-104'. Anal. Calcd. for CilH1aO&: C, 55.2; H , 5.4; OCHa,26.0; N, 5.9. Found: C, 65.1; H,5.6; OCH*,26.1; N, 5.8. 1-(ehydr~-J15-dimethoxsphenyl) -2-propanone ( N ) Frsc- Bath Column Weight Weight tion temp., temp., crude, purified -The nitroalkene (XIII) (1.1 9.) was dissolved in hot R. Identified as no. C. " C. 6. ethanol (10 cc.) and hot water (25 cc.) added, followed by 165 89 0 08 0 03 l-(l-Hydroxy-3iron powder (2.0 g.), ferric chloride (0.08 9.) and concen99 09 06 niethoxyphenyl'1-2175 trated hydrochloric acid (1 cc.). The reaction mixture 03 02 propanone (111) 185 107 was r d u x e d for five hours, concentrated to about half the 192 111 (Jli 05 Syringaldehyde original volume, then filtered, and the black iron oxide 198 124 18 06 1-(4-Hydroxy-3,3130 37 27 dimetho\yphenyl)-2- washed with hot water. The combined filtrate and wash200 ings were extracted with benzene, the benzene solution ex202 130 03 (JI propanone i [I? tracted with 20% sodium bisulfite, the bisulfite solution 130 06 202 acidified, the sulfur dioxide removed, and the resulting 1-(4-Hydroxy-3,5-dimethoxypheny1)-2-propanorie ( I V ) solution extracted with ether. The ether extract was (Fractions 5, 6 and 7 ) was recrystallized from a mixture of dried and the solvent removed, leaving a residual oil (0.50 petroleum ether (b. p. 30-70') and ether; m. p. (i8-69'; g.) which crystallized rapidly. The benzene solution, conno melting point depression when mixed with the synthetic taining the oxime, was evaporated to dryness and the product. Anal. Calcd. for C11Hlr04: C, 62.8; H, 6.7; residue treated with 7 N sulfuric acid (20 cc.) for twentyOCHa, 29.5; mol. wt., 210.1. Found: C, ti2 9 ; €-I, 6.7; four hours a t room temperature, followed by four hours a t OCHa, 29.5; mol. wt. (Rast), 218. 40'. Extraction of the acid solution with benzene yielded Alkaline Cleavage of 1-(3,4,5-Trimethoxyphenyl)-2- an additional amount (0.12 9.) of the ketone; total yield, propanone.--1 - (4 - Hydroxy 3,5 - dimethoxyphenyl) 2 - 0.62 g. (87% distillable (0.05 mm.)); fine, white, needlepropanone (IV) (0.15 9.) was methylated with diazome- like crystals from a mixture of petroleum ether and ether; thane and the methylated product oxidized by boiling for 111. p. 68-69'. A n d . Calcd. for CllH1104: C, 62.8; H, three hours with a 3% solution of potassium permanganate 6.7; OCHa, 29.5. Found: C, 62.8; H, 6.7; OCHa, 29.4. (25 cc.). The reaction mixture was extracted with ether, Semicarbazone of 1 - ( 4 - H y d r o ~ - 3 , 5 - d ~ y l ) then acidified and again extracted. The second extract 2-propanone (rv).-Fine, white, needle-like crystals from contained 3,4,5-trimethoxybenzoic acid (0.053 g.) ; re- ethanol; m. p. 155-156'. Anal. Calcd. for C1611,OINs: crystallized from water; m. p. 165-167'; no melting point C, 53.9; H, 6.4; OCH3, 23.2; N, 15.7. Found; C, 54.0; depression when mixed with an authentic sample of 3,4,5- H, 6.5; OCHs, 23.1; N, 15.5. trimethoxybenzoic acid. 2-Nitro-l-(ehydroxy-3-~ethoxyphenyl)-1-propene Semicarbazone of 1 - ( 4 ~ y & o ~ - 3 , 5 - d ~ e t h o ~ ~(XIV).-Vanillin yl)was dissolved in a minimum amount of ?-propanone (N) .-Fine, white, needle-like crystals from warm ethanol and condensed with nitroethane, the techethanol; m. p. 155-156'; no melting point depression nique being the same as that used for the preparation of when mixed with the synthetic product. A n d Calcd. IXIII); yield, 75%; m. p. 99-100"; recrystallized from for C 1 ~ H I ~ O , NC, ~ : 53.9; H , 6.4; OCH,, 23.2; IS,15.7. ethanol and from ether; m. p. 101-102'; yellow plates. Found: C, 53.8; H , 6.6; OCH3, 23.1; N , 15.8. Anal. Calcd. for CloH1IOIS: C, 57.4; H, 5.3; OCHI, Semicarbaame of 1-(4-Hydroxy-3-methoxyphenyl)-2- 14.8: N, 6.7. Found: C, 57.5; H, d.4; OCHe, 14.7; Ii, propanone (III).-Fine, white, needle-like crystals from (i.6. ethanol; m. p. 157-158"; 110 melting point depression when 1-(4-HydroxyJ-methoxyphenyl) -2-propaaone (111) tnixed with the synthetic product. Anal. Calcd. for The nitroalkene (XIV) was reduced with iron and C11H15OshT3: C, 55.7; H , 6.3; OCHa, 13.1; N, 17.7. hydrochloric acid a s described in the preparation of (IV); Found: C, 55.7; H , 6.5; OCHa, 13.1; N, 17.7. total yield, 70%. The yellow oil was 94% distillable; b. p . Thiosemicarbazone of 1-(4-Hydrox~r-3-rnethox~henyi) 115' (0.15mm.), n2% 1.5444. Anal. Calcd. for CI&ZO:~: 2-propanone (IT[).-Microscopic, white, needle-like crys- C, 66.6; H, 6.7; OCHI, 17.3. Found: C, 66.5; H , 6.7; tals from ethanol; m. p. 187-188'; no melting point de- OCHa, 17.1. pression when mixed with the synthetic product. Anul. Semicarbazone of 1-(4-Hydroxy-3-rnethoxyphenyl)-2Calcd. for CIIH,sOzSNa: C, 52.2; H, 6.0; OCHs, 12.3; N, propanone (ID).-Fine, white, needle-like crystals from 16.6. Found: C, 52.2; H, 6.4; OCHs, 12.4; N , 16.6. ethanol; m. p. 157-158'. Anal. Calcd. for CllHlt03N:8: Synthesis of l-f4-Hydroxy-~,S-dietho~yphenyI)-Z-pro- C, 55.7; H, 6.3; OCHs, 13.1; N, 17.7. Found: C, 55.8; panone (IV) and 1-(4-Hydroxy-3-methoxyphenyl-2-pro- H, 6.5; OCHo, 13.1; N, 17.4. Thioeemicarbnzone of 1-(4-Hydroxy-3-methoxyphenyl) panone (111) 2-Nitro-1-( 4-hydroxy-3,5-dimeth~phenyl) 1-propene 2-propanone (m).-Microscopic, white, needle-like crys(XIII).-Syringaldehyde (3.0 9.) was dissolved in ethanol tals from ethanol; m. p. 187-188" (rate of heating 5-6" (12 cc.) and, t o the solution, nitroethane (1.5 cc.), methyl- per minute). Anal. Calcd. for ClIH1502SNa: C, 52.2; amine hydrochloride (0.1 9.) and sodium carbonate (0.08 H,6.0; OCHs, 12.3; N, 16.6. Found: C, 52.1; H, 6.2; g.) were added. After s t a n d i for fourteen days a t room OC&, 12.4; N, 16.7. Catnlytic Reduction of 2-~irO-l-(4-hy&ory-3-methtemperature in the dark, the reaction mixture was cooled to 0'. the orange needle-like crystals filtered off, washed orgphon~l)-l-propene(XIV).-Animal charcoal was heated T A B L E 111 FRACTIONAL DISTILLATION OF THE MIXTUREOF 1 - ( 4 - H ~ DROXY-3-METHOXYPHENYL)-2-PROPANONE(111) AND 1-(4HYDRoXu-3,3-DIMETHoXYPHENYL-2-PROPA"E) (I\.) (PRESSURE, 0.25 MM.)
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AND PROPERTIES OF SUBSTITUTED PROPANONES AND METHYLETHERS 1185 June, 1943 SYNTHESIS
on a steam-bath, with a mixture of 20% hydrochloric acid reduction of the nitroalkenes under similar conditions a t containing a few cc. of concentrated nitric acid, until the room temperature, but only low yields (15-25%) of the supernatant solution no longer contained iron. The char- ketones were obtained. coal was filtered off, washed with water and dried a t 100" Acknowledgment.-The authors wish t o under reduced pressure (15 mm.) for eight hours. This thank Canadian Industries Limited for kind purified charcoal was activated by heating (luminous flame financial assistance, in the form of a fellowship of a Bunsen burner) in a n evacuated test-tube (20 mm.) for to one of them (M. K.). fifteen minutes. The activated charcoal (3.0 g.) was suspended in a mixture of palladium chloride (0.5 g.) in Summary concentrated hydrochloric acid (0.5 cc.) and water (25 cc.), 1. Two additional products, 1-(4-hydroxy-3,3and cooled to 5". While the suspension was stirred vigorously, 40% formaldehyde (10 cc.) was added, followed by dimethoxyphenyl)-2-propanoneand 1-(4-hydroxya drop-by-drop addition of a 50% solution of potassium 3-methoxyphenyl)-2-propanone have been isohydroxide (10 cc.), the temperature being kept below 5'. lated from the water-soluble lignin ethanolysis The temperature of the mixture was raised slowly t o 60' and maintained there for a few hours. The catalyst was fraction of maple wood. 2. The similarity of their side-chains and those filtered off, washed successively with water, dilute acetic acid, and hot water until the filtrate gave no test for chlo- of previously-isolated lignin entities with those ride, then dried under reduced pressure. present in the phenol carboxylic acids obtained by The palladiumized carbon (0.5 9.) was suspended in a the action of molds on glucose as sole organic subsolution of 2-nitro-l-(4-hydroxy-3-methoxyphenyl)-l-propene (XIV) (2.0 g.) in pyridine (25 cc.) and the suspension strate (Raistrick and Oxford) is pointed out. 3. The specific variation noted in the nature of shaken in an atmosphere of pure hydrogen a t 60-65' until 3 moles of hydrogen had been absorbed (eight hours). the side chain of the latter products when the The catalyst was filtered off and washed with pyridine. mold functions with a shortage of metabolite The solvent was removed from the combined filtrate and provides indirect evidence in support of Hibbert's washings under reduced pressure (20 mm.) and the residual oxime hydrolyzed as described above. The ketone (0.94 views on the biological significance of lignin in 9,) (56%) was obtained by extraction of the acid solution. plant metabolism. Raney nickel was also employed as a catalyst for the MONTREAL, CANADA RECEIVED FEBRUARY 23, 1943
[CONTRIBUTION FROM
THE
DIVISIONOF
INDUSTRIAL AND
CELLULOSE CHEXISTRY, MCGILLUNIVERSITI']
Studies on Lignin and Related Compounds. LXVIII. Synthesis and Properties of 1-Ethoxy- 1- (4-hydroxy-3-methoxyphenyl) -2-propanone, 3-Ethoxy- 1 (4-hydroxy-3methoxypheny1)-Z-propanone and Their Methyl Ethers
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BY MARSHALL KULKAAND HAROLD HIBBERT Two isomeric ethyl ethers have been found in the water-soluble ethanolysis products of spruce wood, namely, 2-ethoxy-1-(4-hydroxy-3-methoxyphenyl)-1-propanone (I) and l-ethoxy-l-(4-hydroxy-3-methoxyphenyl)-2-propanone(11). 2 A third isomer, 3-ethoxy-1- (4-hydroxy-3-methoxyphenyl)-1-propanone (111)3 has been synthesized but not as yet isolated from the ethanolysis products of spruce or other woods. A fourth isomer of this series, 3-ethoxy-1- (4-hydroxy-3-methoxyphenyl)-2-propanone (IV) representing the ethyl ether of the first member of the Hibbert system4of plant respiratory catalysts has been neither synthesized nor isolated from the ethanolysis products. (1) (a) Cramer and Hibbert, THIS JOURNAL, 61, 2204 (1939); (b) Cramer, Hunter and Hibbert, ibid., 61, 509 (1939). (2) E. West, MacInnes and Hibbert, ibid., 65, 1187 (1943). (3) (a) K.A. West and Hibbert, ibid., 65, 1170 (1943); (b) K.A. West, Hawkins and Hibbert, ibid., 6S, 3035 (1941). (4) Hibhert, A i i i i . R~zr Rio(hesi., 11, 183 ( l W 2 ) ,
The purpose of this investigation was to synthesize the isomeric ethyl ethers (R-CH(0C2H5)COCH8) (11) and R-CH2COCH2(0C2H5) (IV) and to compare their properties with those of R--COCH(.OC~H~)CHB(I), and R-COCH2CH2(OCzHs) (111) (R = 4-hydroxy-3-methoxyphenyl). The isomer I1 was synthesized by the following procedure CHaO\ AcO-~CH-CO-CH3
I
AgOAc EtOH
OEt (VI)
