[CO'JTRIBITTIOVNO.486
FROV THE INISTITUTE FOR ATOMICRESEZRCH ZND THE Z)EPIRT\fIC\T 0 1 CHl2\lI>TRY, I O W Z ST4TE
Preparation and Properties of Some Alkyl-1,2-Cyclohexanedione Dioximes2 CHAR1,RS T'
BANKS, DONALD T . HOOKER,3
AND
JOHN J RICHARD
Reeeiited Februaiij 3, 1956
anols which, in turn, were oxidized, in good yields, to the expected nlkylcyclohexanones 1 9 7 an ncidIt has Ileen knon-n for some time that certain dichromate mixture.21 These alkylc~clohexanones alicyclic nic-dioximes possessed properties making were then oxidized with selenium dioxide23s21 to the them usefiil as analytical reagents for nickel and corresponding alkvl-l,2-cyclohexanediones vhich palladium. 4 - g In connection with a recent searchlo were then oximated to alkyl-1,2-cyclohexanediovle for morc desirable alicyclic zic-dioximes it became dioximes with aqueous hydroxylamine.23 The propadvisahle t o synthesize a series of alkyl-1.2-cyclo- erties of these alkyl-l,2-cyclohexanedionedioximcq hexanedione dioxjmes (alkylnioximes). are discussed and related to their structures. Some nlkgl-l,2-cyclohexanedionedioximes have heen previously prepared by several investigaPREPARA4TIO?; O F THE UiC-DIOXIMES tors,"-'" hut Ihe yields have been small, the interMaterials and apparatus. 4-tert-il ?nylc~jclohexanal was mediates cxpcnsive, or the details of the procedure not reported. The present paper is concerned with obtained from Sharples Chemical Company, '\J-yantlot te, 4-lsopropylcyclohexanol was secured from the the preparation and properties of the following nMichigan. o w Chemical Company, Midland, llichigan. T h r Rohm alkyl-] ,2-cyclohexanedione dioximes : 4-methyl-, and Haas Company, Philadelphia, I'ennPylv:ini:i, supplied +isopropyl-, 4-fert-amyl-, 4-(1,1.3,3-tetramethyl- the ~-(i,l,S,S-tetramethy16~~t~Z)phenol. The otjher phenols, butyl)-, 3-methyl-, 3-ethyl-, and 3,6-dimethyl-l,2- cyclohesanols, and cyclohexanones were obtained from cvclohexnnedione dioxime. A lkylphenols mere hy- Distillation Products Industries, Roehest,er, S e w Yorli. The Raney nickel catalyst was obt,ainetl a8 a nickel-alumidrogenated at high pressure over a Raney nickel niim alloy from Central Scientific Company, Chicago. catalystIfi-2o i o the correqponding nlkylcyclohex- Illinois, and was activated by boiling viith sodium hydrosIYTRODTCTIO?rr
(1) The espcriineat~swere performed in the Ames Laboratory of the Atomic Energy Commission. ( 2 ) No. XVIII in a series on "Chemistry of the vicDioximea.!' Previous paper in this series is S o . XVII, Anal. Chem., 28, 79 (1956). (3) Abstract8edfrom a dissertation suhmitted by Donald T. Hooker t o the Graduat,e Faculty of Iowa State College in partial fulfillment of the requirements for the degree of Doctor of Philosophy1 1955. Present addr Gamhlc Co , Cincinn:rti 17, Ohio. (4) T'otrr, n:inIw, and Diehl, Anal. Chem., 20, 458 (1048). ( 5 ) T'otc'i,, I3nn!w. :tncl Dic,hl, Anal. Chem., 20, 652 il948). (6) Fcrqwon, '\-ot.er, and Banks, Mikroehem. iw. Mikrochin2. ilctn, 38, 11 (1951). (7) Voter and Banks, d n a l . Chenz., 21, 1320 (1949). (8) Fergiison and Banks, ilnnl. Chcm., 23, 448 (19511. (9) Fergiison and Banks, Anal. Chenz., 23, 1486 (1951). 110) I3anlis antl Hooker, Anal. Chem., 28, 79 (1956). (11) Kiitz, hIiisslnum, 2nd Takens, *J. p m k t . Chem., [ Z ] 90, 357 (1931). (12) Wnllach. Ann., 414, 296 (1916). (13) K d l : i c ? i ~Snchr. Ocs. W'iss. Gottingen. .Ilafh. physik. K l a ~ s e 85 , (1923). (14) 1Tnll:irh nnrl Keisscnhorn. A n n , 437. 148 (1924) (1.5) Gotlchot arid Cauquil, Compt. rend., 202, 326 (19361. (16) Cloueh, Hunter, and Rcnyon, J . Chenr. SOC.,2052
ide as directed by the mannfadturer. Selenium dioxide was obtained from the American Met,als Company, I,imit"l, Ken- York City, New Yorlr, and was used withoutj furt,her purification. All of the other rhemicals employed in t'hr preparation were C.P. grade or their equivalent. A Paar, Series 4000, Higli Pressure Hydrogenation Apparatus manufactured by the Paar Instrument, Conip lfoline, Illinois, was used for the hydrogenations. This rocking type hydrogenator with a 1000-milliliter bomb. Alkylcycloheranols. The alkylphenol T ~ purified P by frnrtional distillat,ion through n 50-vm. T'igreu.; column under redured pressure. One mole of tht: purified nlkylphenol together with 2 g. of the Raney uirlcel catalyst wns suspended in 150 nil. of ethanol antl placed in the homl). Hydrogen was int,roduced to a pressure of 1800 11.s.i. antl the bomb was heatcd t o 150". When t,ho pressure of thc tmmh had fallen to that calculated for complote hydroganation (1 to 1 hours), the boml) was cooled and opcnetl and t,he contents n-vere filtered to remove t,he rntnlyst. The filtrate was fractionated through a 50-em. Yigrcus colnmir and the nlkylcyclohexanol was collected. Tht. yields : ~ n d properties are given in Table I. ~llk~jlc~/clohernnone.~. The nlkylc~rlohesniiols, ol)t:iincd either commercially or synthesized as directed above, were purified by distillation. The acid-dichromatr met,hod o f Sickels and Heintzelman21 was used t,o ositlizc the alkylryclohesanols t o the corresponding :illtylcyclohc~nno!ic~ In thip method 100 ml. of conc'd sulfuric acid was addc.il to a vigorously stirred mist,ure of one mole of the nlkylryrl~ihmnnol and 1 Mer of xvnter. The vigorous stirring n-ns eon-
(1 926). 117) bfiirnt, :Inm. chim., [SI 16, 108 (1908).
(18) I'inw a n d Ipatieff, .I. A m . Chem. Soc., 61, 2728 (1 939). (19) Sa1)nticr and Senderens, A n n . chinz., I S ] 4, 319 (1905). (20) I-ngnad(~:md hlcT,nrcn, J . Am. Chem. SOC.,66, 118 (1941). 547
(21) Nirkels and Hrintxelman, J . Org. Chon., 15, 1142 (1 950). 122) Hnch. Banks. and Diehl, Orq. Svntheses. 32, 35
(1952). (23) VandPr IT:tnr, Voter, and Baii!~~, J . O r g C h e n ~ ,14, 836 (1949).
548
VOL.
BANKS, HOOKER, AND RICHARD
21
TABLE I PROPERTIES AND YIELDSOF ALICYCLICINTERMEDIATES
--
B.p. range, "C.
Mm.
2,5-Dimethylcyclohesanone
163-165 185-190 64-65 115-123 162-165 75-77 176-179
758 751 12 4 754 12 755
4-Isopropylcyclohexanone 4-tert-Amylcyclohexanone 4-Octyl~yclohexanone~ 3-Methyl- 1,2-cyclohexanedione 4-Methyl-l,2-cycloheuanedione 3-Ethyl-l,2-~yclohesanedione 3,6-Dimethyl-l,2-cyclohexanedione CIsopropyl-lJ2-ryclohexanedione Ctert-Amyl-l,2-cyclohexanedione 4-Oct yl-l ,2-cyclohe.tanedionea
84-86 110-113 91-95 80-86 90-95 90-95 85-90 77-84 111-118 137-143
10 12
Intermediate 2-hlethylc yclohexanol 3-Ethylc yclohexanol
2,s-Dimet hylcyclohexanol 4-Oc t ylcyclohexanola 2-Methylc yclohexanone 3-Eth ylc y clohexanone
1
12 16 6 6
1 4 1
ALP., "C.
-
n: * 1.4638
-
1 1650 1 4580
-
1.4635 1,4494 1,4430 1,4447
-
1,4562
-
96 102 62 35 71
-
65-70 75-80 90-95
-
-
1 5002 -
-
Yield,
5%
Referenrrs
91 92 94 80 85 82 82
17, 26-31 20, 3t5 20, 36-42 43, 4 1 2t;-28, 3 I , 16-50 35, 51-55 36, 39, 41, 51, 56-58 t50, 58-03 50 41 12, 14, 6-1-65 14, 15 Sone Sone None Sone None
81 84
86 20 34 19
2 29 38 40
Octyl is 1,1,3,3-tetramethylbutyl.
(24) Riley, Morley, and Friend, J . Chem. floc., 1875 (1932), (25) Fieser and Ourisson, J . Am. Chem. Soc., 75, 4404 (1953). (26) Zelinsky and Generosow, Ber., 29, 729 (1896). (27) ITallach and Franke, Ann., 329, 368 (1903). (28) Sabatier and Mailhe, Compt. rend., 140, 350 (1905). (29) Wallach, Ann., 359, 307 (1908). (30) Skita, Ann., 431, 1 (1923). (31) Auwers, Hinterseber, and Treppman, Ann., 410, _. 257 (1915). 132) Skita and Faust. Ber.. 64. 2884 (1931). t33j Huckel and Hagenguih, ber., 64, 2892 (1931). (34) Aneiani and Cornubert, Bull. soc. chim. France, 857 (1948). (35) Adams, Loene, Theobald, and Smith, J. Am. Chem. Soc., 64, 2653 (1942). (36) Sabatier and Mailhe, Compt. rend., 142, 553 (1906). (37) Skita, Ber., 55, 139 (1922). (38) Skita and Schneck, Ber., 55, 144 (1922). (39) Skita, Be?., 56, 2234 (1923). (40) Godchot and Bedos, Compt. rend., 178, 1184 (1924). (41) Godchot and Bedns, Bull. SOC. chim France, [4] 37, 1637 (1925). (42) Chiurdoglu, Bull. soc chim. Belg., 47, 241 (1938). (43) Brwon and Covert, U. S. Patent 2,026,668 (Jan. 7, 1936). (44) Nirtlerl and Smith, J . Am. Chem. Soc., 59, 715 (1937). (45) Kay and Perkin, J . Chem. Soc., 87, 1066 (1905). (46) Bouveault and Chereau, Compt. rend., 142, 1087 (1900). (47) Wallach, Ann., 346, 249 (1906). (48) Skita, Ber., 56, 1014 (1923). (49) Mousseron, Jullien, and Winternitz, Compt. rend., 226, 1909 (1948). (50) Harvill. Roberts. arid Herbst. J . Ora. Chem.,. 15.. 58'(1950). ' (51) L6ser, Bull. SOC. chim. France, [3] 25, 199 (1901). (52) Braum, Mannes, and Reuter, Ber., 66, 1499 (1933). (53) Whitmore and Pedlow, J . Am. Chem. Soc., 63, 758 (1941). (51) Ungnadp and McLaren, ,I. Org. Chem., 10, 29 (1 945).
tinued while one liter of an aqueous 10% solution of potaesium dichromate was added a t such a rate as to keep the temperature of the oxidation mivture between 55" and 60'. An ice-bath was used to control the temperature. After addition of the potassium dichromate was complete, the solution was stirred for another hour and allowed to cool. The aqueous layer was separated from the lighter organic phase and extracted with three 100-ml. portions of diethyl ether. The ether and organic phases were combined and washed with three 50-ml. portions of a 20% aqueous solution of potassium hydroxide, followed by two 50-ml. portions of water saturated with sodium sulfate. The ether phase was dried with sodium sulfate and fractionated t o recover the ketone. Properties and yields of the ketones are listed in Table I. Alkyl-1,d-cyclohexanediones. The alkylcyclohexanones, obtained either from commercial sources or prepared as described above, were oxidized with alcoholic selenium dioxide to yield the corresponding alkyl-1,2-cyclohexanediones. The method reported by Riley, et al. as modified by Hach, Banks, and Diehlzz was employed. One mole of the alkylcyclohexanone was dissolved in 300 ml. of ethanol and placed in a one-liter flask equipped with a stirrer, reflux condenser, and dropping-funnel. One mole of selenium dioxide was dissolved in 200 ml. of 95% ethanol and the solution was added dropwise to the stirred solution of the alkylcyclohexanone. Heat was supplied by means of a steam(55) Woods, Griswald, Armbrecht, Blumenthal, and Plapinger, J . Am. Chem. Soc., 71, 2028 (1949). (56) Kotz, Ann., 357, 202 (1907). (57) Harding, Haworth, and Perkin, J . Chem. SOC.,93, 1970 (1908). (58) Wallach, Ann., 397, 181 (1913). (59) Wallach, Ann., 343, 28 (1905). (60) Vavon and Callier, BuU. soc. chim. France, [4] 41, 678 (1927). (61) Cahn, Penfold, and Simonsen, J . Chem. Soc., 1366 (1931). 162) Frank. Berrv. and Shotwell, J . A m . ('hem. SOC., . 71,. 3889 i1949). ' (63) Jackman, hlacbeth, and Mills, J . C h ~ m Soc., . 2641 (1 949). (ai) Harries, Ber., 35, 1176 (1902). (05) Wallach, Ann., 418, 36 (1918). "
I
MAY
1956
549
ALHYL-1,2-CYCLOHEXANEDIONE DIOXIMES
TABLE I1
PROPERTIES OF V~C-DIOXIMES Analyses Yield, %
uic-Dioxime 2,3-Butanedioncdiosime Sioximea 3-hlethylnioxime 4-Methylnioxime 3,G-Dimethylnioxime 3-Ethylnioxime 4-Isopropylnioxime 4-tert-ilmylnioxime 4-Octylnioxime" a
GO 70 52 65 72 80 70
Calc'd C
53.83 53.83 56.44 56.44 59.31 62.23 66.11
H
M.p., "C.
Molecular Weight
7.52 7.50 8.29 8.23 8.73 9.51 9.96
240 188 164-165 181-182 160-161 179-180 184-185 202-204 199-201
116 142 156 156 170 170 184 212 254
Found
C
H
7.74 7.74 8.11 8.11 8.85 9.49 10.30
53.99 53.79 56.44 56.80 59.19 62.55 66.37
Molar Solubility, 34 X 104
References
34 58 256 218 474 144 41 1.1 0.004
12-14 11, 14, 15 None Xone None None None
Nioxime is 1,2-cyclohesanedione dioxime. For convenience the alkyl-1,2-cyclohexanedione dioximes reported in Table 4-Octylnioxime is 4(1,1,3,3-tetramethylbutyl)-1,2-cyclohexanedionedioxime.
I1 are listed as derivatives of nioxime.
bath until the ovidation started nnd then the temperature wns maintained abovc 70" bv the rate of addition of the selenium dioxide. An excess of unreacted selenium dioxide in the presence of the alkylcyclohesanone is to be avoided since a violent renction may take place under this condition When the addition of the seleniiim dioxide was completed, the mixture was stirred and refliived on a steam-bath for six hours. The reaction mixture was stiried for an additional si-; hours a t room temperature, after which time the precipitated selcnium metal was filtered off and the darkcolored filtrate WAS fractionated through a 50-cm. Vigreux column under reduced pressure. I n the case of the higherboiling alkyl-1,2-cyclohe~anediones, some selenium appeared in the distillate and was removed by stirring with freshly precipitated silver metal as described by Fieser and Ourisson.26 The once-fractionated alkyl-1,2-cyclohexanedione mas then distilled a second time. Hot water was used in the condenser to prevent clogging by solidification of the alkyl1,2-cyclohexanedione. The yields and properties are given in Table I. AIkyl-l,2-cgclohexanedione dioximes. The alkyl-lJ2-cyclohexanediones were osimated by treatment with aqueous hydroxylamine as described by Hach, Banks, and Dieh1.22 In the case of the higher molecular weight alky1-lJ2-cyclohexanediones, up to 50 per cent ethanol was added to the oximation solution in order to increase the solubility of the alkyl-uic-diones. The alkyl-1,2-cyclohexanedionedioximes were recrystallized from ethanol-water mixtures. The yields and properties of the dioximes are listed in Table 11. DISCUSSION
Most of the reactions proceeded as expected with good yields. The selenium dioxide oxidations were the most difficult reactions to carry out and resulted in some unexpected prodixcts. The 4-alkylcyclohexanones yielded the expected products. However, 2-methylcyclohexanone gave 3-methyl1,2-cyclohexanedione as the major product rather than 3-methyl-3-cyclohexene-1 ,Zdione as previously reported by Godchot and Cauquil. This was determined by quantitative hydrogenation of the methylalicyclic-1,2-dione.Only two moles of hydrogen were absorbed per mole of the methylalicyclic-l,2-dione, thus indicating that the product mas 3-methyl- 1,2-cyclohexanedione. I n addition, the carbon and hydrogen analysis of the resulting vicdioxime corresponded to a saturated aliphatic ring.
Similarly the 3-ethylcyclohexanone might have been expected to yield 3-ethyl-3-cyclohexene-l,2dione, l5 but again quantitative hydrogenation indicated a saturated aliphatic ring. A dibasic acid was isolated as a product of the periodate oxidat,ion of the ethylalicyclic-l,2-dionewhich had an equivalent weight of 87, melted a t 48", and gave a pphenylphenacyl derivative melting at 118". This acid mas characterized as alpha-ethyladipic acid.66 Therefore, the product was 3-ethyl-l,2-cyclohexanedione. The elemental analysis of the corresponding vie-dioxime also indicated a iaturated aliphatic ring. It must be noted, however, that the yields of the 3-alkyl-1,2-cyclohexanediones mere less than the corresponding yields of the 4-alkyl-1,2-cyclohexanediones. These reduced yields could be due to the formation of some unsaturated vic-dione which was not isolated. The very low yield of the 3,6-dimethy1-ll2-c~~clohexanedione was due to major formation of a lower-boiling, yellow liquid which was identified as 3,6-dimethyl-l,2-benzoquinone.The formation of this quinone was not surprising since the work of Godchot and C a ~ q u i l 'indicated ~ that dehydrogenation might occur when 2- and 3alkylcyclohexanones are oxidized with selenium dioxide. PROPERTIES OF THE V~C-DIOXIMES
Materials and apparatus. The alkyl-1,2-cyclohexanedione dioximes were recrystallized from water or water-ethanol mixtures at least three times, followed by a recrystallization from petroleum ether-benzene mixture. All chemicals used were of reagent-grade or equivalent purity. The absorption spectra taken with varying wavelength were all obtained with a Cary recording spectrophotometer, Model 12. The absorption measurements made a t constant wavelength were obtained with a Beckman Model DU spectrophotometer. A Beckman, Model G, pH meter was used for all of the pH measurements. Decomposition ranges. All of the alkyl-1,2-cyclohexanedione dioximes reported here are white, crystalline solids (66) Brown, Rose, and Simonsen, J . Chem. Soc., 101 (1944).
Z50
BANKS, HOOKER, AND RICH.4RD
VOL.
21
which melt, m-ith decomposition. Thc decomposition ranges about the carbon-carbon bond bctween the adare given in Table IT. jacent oxime groups and thus seriously interfere Solubilities. Saturated aqueous solutions of the alkylwith the formation of hydrogen-bonded chains. 1,2-cyclohexanedione dioximes were prepared by shaking 3-?tlethyl-lJ2-cyclohexanedionedioxime melts suspensions of excess oic-dioxime in 75 ml. of water for one week. One set of solubility determinations was made on 17" below- 4-methyl-l,2-~yclohexanedione dioxime solutions saturated a t 25" and then shaken at 25", while and 23" below the parent compound, lJ2-cyclohexanother set was made on solutions saturated at 90" and then anedione dioxime. This indicates that substitution shaken at 25". The excess ,-dioxime was filtered off and an aliquot of the aqueou8 soli on \vas treated wibh an aqueous in the 3-position is more effective than substitution solution containing nickel(I1) ions. The weight of the his- in the 4-position in hindering intermolecular hy(alkyl- 1,2-~gclohexnnedioriedioximnto-S,.V') nickel( TI ) ~ n s drogen bond formation. The fact that 3,A-dimethyldetermined's nntl the soluldity wa.q calcu1:ttcd. For the more 1,2-cyclohexanedione dioxime melts at the same insoluble alkyl-l,2-cyclohesanetfionc diosimes the bis(vicas 3-methyl-l,2-cyclohexanedioncditemperature dioxim:Lt,o-~,12T')niclicl(II) complcs vias not weighed, hut was d&rniined c;unntitatively by n spectrophotometric oxime while 3-ethgl-l,2-cyclohexanedionedioxime in a later report. The solu- melts 15" higher, is further evidence that substitiiiolet nntl visiblc absorption Rpcctr:i of the nlkyl-l,2-ryclohesnncdionediosinies reported here were scanncd on n Gary recording spcctrophotomctm. The spectra. were nll quite similar t>o that previously retported for 1,2-cyclol~t~snnetlione ~ i i o s i m e .Only ~ ~ onc ahsorption nirtsini:i w:ia olmrved for each :Llkyl-iIic-tiiosime in cnch rase, locxtcd :at) 232 mp. The 8 6 , :it 232 mp vnrictl from 7800 to 7900, tlic hiptier moleciilnr R-c,ight romporinds having t,hc slightly higlicr vdiie. DISCUSSIOS
A compzrison of the physical properties of the vie-dioximrs offers significant information. Thc crystal structure of 2.3-hutanedionc dioxime has heen determined by single crystal methods by Merritt and L a i i t e r ~ n a nThe . ~ ~ crystal was found to be composed of chains of essentially planar, centrosymmetric 2,3-butanedione dioxime molecules joined togother by a netn-ork of hydrogen bonds. Such a structure is consistent with the high melting point (2.10") a i d the low aqueous solubility (0.0034 molar) for snch a low molecular weight, 116, compound as 2,3-butanedione dioxime. It is interesting to note that the higher moleculnr wight, lbti to 254, alky1-1,2-cyclohexanedioiiedioximes comistently melt at a significantly !on cr temperatnre (160 to 205") than do straight ch;iin aliphatic zt,'c-diosimes such as 2,3-butanedione tlioxime. This is not unexpected, ho\yewr, since t hc alicyclic ling T\ ould greatly restrict thc rotation ____ (67) Banks,
C:lrlson,
phil,{ ilcta, 7 , 201
(1 952).
(68) Molar ahsorptivitv, e , is ruprrswl in unit4 of lit(w/(mole-rcntimctci ). (0) IIcriitt and Lantrvman, Acta P, i p t , 5 , 81 1 (1052)
tion in the positions adjacent to the oximc qroups is quite effective in hindering intermo1ecul:w hydrogen bond formation. The aqueous solubilities of the vicdioximes likewise indicate that both rotation about the carboncarbon bond between the adjacent oxime groups and substitution in the 3-position of the alicyclic ring markedly affect the constitutive properties of the crystalline state of these compounds. It has been previously reported' that the molar solubility of I ,2-cyclohexanedione dioxime in m t e r is 17 times that of 2,3-butanedione dioxime. The greatly increased solubility of lJ2-cyclohexa~iedionedioxime over the lower molecular weight 2,3-butanedione dioxime again strongly indicates decreased in tcrmolecular hydrogen bonding in the former case as a result of restricted rotation of the oxime groups lw the nlicyclic ring. 3-Methyl-l,2-cyclohexanedionedioxime is about 187, more soluble than 4-methyl-lJ2-cyclohexanedione dioxime, while 3,6-dimethyl-lJ2-cyclohexai:cdione dioxime is more than twice as soluble. ,1gain, the effect of substitution in positions adjacent to the oxime groups is quite apparent. Increasing the size of the substituent group in the 4-position simply results in the expected decrease in solubility 1)ecnnsc of increased molecular weight. It appears from both the melting point and thc soluhility data that substitution in the 4-position offers little interference to crystal formation. The fact that the absorption spectra of all the alkyl-lJ2-cyclohexanedionedioximes were almost identical indicates that in aqueous solution the substitucntq on thc ring have very little effect on the dioximc groups. IVCS, IOWA
