March, 1936
CONDENSATIONS OF ALIPHATIC ALCOHOLS [CONTRIBUTION FROM m D Z I E CHEMICAL LABORATORY,
MICHIGAN STATE
430
COLLEGE]
Condensation of Aliphatic Alcohols with Aromatic Compounds in the Presence of Aluminum Chloride. I' BY R.c. HUSTONAND T. Y.HSIEH~ Papers from this Laboratory3 have described the condensation of aromatic and unsaturated aliphatic alcohols with aromatic hydrocarbons and phenols by means of anhydrous aluminum chloride. These experiments indicated that unsaturation of the alpha-carbon atom, whether it be double bonded or a member of the benzene ring favors condensation. The followingsaturated aliphatic alcohols did not condense to an appreciable extent with benzene under the same conditions used in the condensation of aromatic or unsaturated alcohols, viz., methyl) ethyl, propyl, i40propyl, isobutyl, isoamyl, phenylethyl and phenyl propyl alcohols. By using a slightly modified technique fair yields of condensation products have now been obtained with benzene and the following secondary alcohols : isopropyl, s-butyl, methyl-n-propylcarbinol and methylisopropylcarbinol. Under the same conditions primary alcohols up to and including n-hexyl alcohol did not react. In these condensations 0.5 equivalent of aluminum chloride was added to from 2 to 5 equivalents of benzene. The mixture was vigorously stirred while one equivalent of the carbinol was added drop by drop from a dropping funnel. The temperature was kept below 30". The usual reaction phenomena were exhibited : hydrochloric acid was evolved and the reaction mixture turned a deep red. After standing overnight, the mixture was decomposed with ice and hydrochloric acid. The benzene layer was removed and the aqueous portion extracted with ether. The combined ether and benzene extract was finally fractionated through a 30-cm. column. Dimeth~lphenylmethane~ (cumene) (b. p. 152154O), methylethylphenylmethanes (b. p. 172(1) The material in this paper, together with information on the conde~sationof t-butyl, I-amyl and i-hexyl alcohols with benzene was presented before the Organic Section of the American Chemical Society at its meeting Sept. 10-14, 1934, a t Cleveland, Ohio. See Tzukcrvanik, J . Gen. Ckem. U. S. S. R.,I , 117, 784, 767 (1935) (C. A . OS, 4746 (1935); 40, 443 (1936)). (2) From a thesis submitted in partial fulfilment of the requirements for the Ph.D. degree. (3) R. C. Hustoo and K. Goodemgot, THIS JOURNAL, 56, 2432 (1934); R. C. Hustoo and A. L. Houk. i b i d . . 64. 1506 (1932) (4) Jacobsea, Bcr.. 8, 1280 (J876); Gustavson, ibad, 11, 1261 (1878); Radziewaooski. ibrd 28, 1137 (1895) t6) Klages, ibid , 86, 2642, 9509 (1902)
174O), methyl-n-propylphenylmethane6 (b. p. 191-193'), methylisopropylphenylmethane7 (b. p. 189-191Q)were prepared in this way 6y condensation of the corresponding secondary alcohols with benzene, with yields of 26-28%. Application of a similar technique to the condensation of t-butyl alcohol and benzene gave a 67% yield of trimethylphenylmethane. Of a number of alcohols studied, those eontaining the tertiary groups were found to be much more reactive thas the secondary alcohols, indicating as a second factor a relationship between the number of alkyl groups on the carbinol carbon atom and the tendency of the hydroxyl group to eombine with a hydrogen of the aromatic ring to form water.
Condensation with Phenol Investigations of the condensation capabilities of primary aliphatic alcohols (ethyl) propyl and butyl) in which aluminum chloride was added to a solution of the alcohol and phenol in an inert solvent, gave negative results. Under similar conditions, s-propyl alcohol reacted to give a araall amount of a compound still under investigation which does not correspond in properties to any of the known propyl phenols or pheoyl propyl ethers. Secondary butyl alcohol did not react. Tertiary aliphatic alcohols were found to condense readily with phenol to give the para alkyl phenol. In these condensations a technique similar to that employed in the condensation of aromatic alcohols and phenols was used.8 A mixture of the tertiary alcohol (0.25 mole) and phenol (0.25 mole) was suspended in a suitable inert solvent such as petroleum ether and stirred mechanically while anhydrous aluminum chloride (0.125 mole) was added at a rate which maintained the temperature between 25 and 30". The mixture was allowed to stand for several hours and was then decomposed with ice and hydrochloric acid. The alkyl phenol was isolated either by fractionation of the ether extract or by crystallization. Yields varied between 45 and 60%. ( 8 ) Klages, rbid., 86, 3609 (1902). (7) Rlages, ibrd., 36, 3691 (1903) (8) R C. Huston, THIS JOURNAL, 46, 2776 (1924).
440
R. C. HUSTON AND T. Y . HSIEH
Vol. 58
TABLEI CONDENSATIONS OF TERTIARY ALCOHOLS WITH PHENOL Product
p-1-Butylphenol* p-t- Amylphenol' O
Di-Me-n-Pr-p-OH-Ph-methane Di-Me-i-Pr-p-OH-Ph-methane Di-Et-Me-p-OH-Ph-methane
B. p., 'C. (740 mm.)
M. p., "C.
Carbon, % Calcd. Found
Hydrogen, % Calcd. Found
236-238 248-250 259-261 266-268 268-269
99-100 94-95 37-38 105-106 59-60
80.89 80.89 80.89
10.11 10.11 10.11
80.74 80.80 80.95
10.06 10.00 10.17
Proof of Structure of Tertiary Hexyl Phenols. was suction filtered, washed with cooled ether -The t-hexyl alcohols were condensed with and recrystallized to a melting point of 238 -240'. benzene and each tertiary alkyl benzene was then A mixed melting point determination showed no nitrated by treatment with an equal weight of depression. fuming nitric acid (1.52) a t room temperature for Each of the above p-nitro-hexylbenzenes was two hours." After washing and drying, the prod- reduced to the amino derivative by means of tin ucts were distilled under reduced pressure. and hydrochloric acid under the following conditions. TABLE I1 Thirty grams of tin in a 500-cc. round-bottomed ~-NITRO-~-ALKYLBENZENES, C12HI1O2N flask fitted with an air condenser was treated with B. p. 'C. Nitrogen, % Compound, -methane (3 Am.) Calcd. Found 100 cc. of concentrated hydrochloric acid and then p-Nitrophenyl-dimethyl-n-propyl-124-126 6.76 6.81 20 g. of 9-nitro-t-hexylbenzene. After eight p-Nitrophenyl-dimethyl-i-propyl- 122-124 6.76 6.73 hours the mixture was treated with water and p-Nitrophenyl-diethyl-methyl123-125 6.76 6.70 made alkaline with sodium hydroxide. The TABLE I11 amine was steam distilled, extracted with ether, $-AMINO-~-ALKYLBENZENES, Cl*HloN dried over solid potassium hydroxide and disB. p. "C. Nitrogen, % Compound, -methane (3 Am.) Calcd. Found tilled under reduced pressure. P-Aminophenyldimethyl-n-propyl- 107-109 7.91 7.78 Diazotization of the amines gave in each case p-Aminophenyldirnethyl-i-propyl- 109-111 7.91 7.95 the same phenol as was produced directly by conP-Aminophenyldiethylmethyl108-110 7.91 7.85 densation of the alcohol with phenol by means of A 2-g. portion of each of these nitro compounds aluminum chloride. The following technique was was oxidized by heating with 25 cc. of dilute ni- used. Five grams of p-amino-t-hexylbenzene was tric acid (1.20) in a Carius tube a t 130' for from ten to fifteen hours.1° The mixture was poured treated with 2.5 cc. of concentrated sulfuric acid into 400 cc. of water. The p-nitrobenzoic acid in 15 cc. of water. The solid salt was suspended TABLEIV BENZOYL ESTERS OF p-I-ALKYLPHENOLS Compound
p-t-Butylphenoll* p-t-Amylphenolll Di-Me-n-Pr-p-OH-Ph-methane Di-Me-i-Pr-p-OH-Ph-methane Di-Et-Me-p-OH-Ph-methane
M. orb. p., OC.
M M B M M
Formula
81-82 60-61 169-171(3 mm.) CloHnO 54-55 CiOHzz0 77-78 CipH220
Carbon, % Calcd. Found
80.80 80.80 80.80
80.66 80.71 80.72
Hydrogen, % Calcd. Found
7.86 7.86 7.86
7.65 7.81 7.79
TABLEV BENZENE SULFONYL ESTERS OR $-t-ALKYLPIiENOLS Compound
P-1-Butylphenol fi-t- Amylphenol Di-Me-n-Pr-p-OH-Ph-methane Di-Me4 Pr-p-OH-Ph-methane Di-Et-Me-p-OH-Ph-methane
M. orb. p.. "C. (3 mm.)
M B B B B
70-71 1&1-185 174-175 178-179 183-184
(9) Kreysler, Bet., 18,1717 (1886); Studer, ~ n n .211,246 , (1882). (10) Anschtitz and Beckerhofi, ibid., Sa?, 219 (1903). (11) Malherbe, Be?., 62, 319 (1919). (12) Kreysler, ibid., 18,1717 (1885).
Formula
Calcd.
CioHiaOaS CirH2oOaS C18HzzOs~ CisHzaOsS CiqH220sS
11.03 10.52 10.06 10.06 10.06
Sulfur, %
Found
10.97 10.26 9.88 9.91 9.98
in 300 CC. Of water cooled to 5' and diazotized with 1.9 g. of sodium nitrite in 8 cc. of water. This was added slowly beneath the surface of the stirred
March, 1936
441
Z I N C ON d R O T Y L AND hfETHYLVlNYLCARB1NYL B R O M I b E S
TABLE VI @-TOLUENE SULFONYL ESTERSOF @-t-ALKYLPHENOLS Compound
M. or b.p., OC. (3 mm.)
Formula
Calcd.
p-t-Butylphenol p-t- Am ylphenol Di-Me-n-Pr-p-OH-Ph-methane Di-Me-i-Pr-p-OH-Ph-methane Di-Et-Me-p-OH-Ph-methane
M 109-110 M 54-55 B 194-195 B 187-188 B 1-189
CirHioOsS CiJhOaS CieHzPaS CisHi4OaS Ci9HiiOaS
10.52 10.06 9.64 9.64 9.64
suspension from a dropping funnel the delivery tube of which had been drawn to a capillary. The diazotized solution was then warmed on a waterbath and steam distilled. The tabulated esters were prepared by the pyridine method.'a
Summary 1. Aliphatic tertiary alcohols condense with phenol in the presence of aluminum chloride to give good yields of p-tertiary-alkyl phenols. 2. The benzoyl, benzene sulfonyl and p(13) Einhorn and Holland, Ann., 901, 95 (1898).
(CONTRIBUTION FROM
THE
Sulfur, %
Found
10.44 9.93 9.72 9.57 9.60
toluene sulfonyl esters of five phenols were prepared. 3. Aliphatic secondary and tertiary alcohols condense with benzene to give the corresponding alkylbenzenes. The tertiary alcohols react much more readily and give higher yields than the secondary alcohols. 4. Aliphatic primary alcohols do not condense with either phenol or benzene in the presence of aluminum chloride, under the given experimental conditions. EASTLANSING,MICH.
CHEMISTRY DEPARTMENT OF
THE
RECEIVED OCTOBER 28, 1935
UNIVERSITY OF CALIFORNIA AT LOS ANGELES]
Allylic Rearrangements. 111. The Action of Zinc on Crotyl and Methylvinylcarbinyl Bromides' BY WILLIAM G. YOUNGAND SAULWINSTEIN Crotyl bromide A previous communication from this LaboraCHsCH=CHCHIBr tory2 mentioned the possibility of allylic rearrangement during the preparation of butenes from C H ~ H CHaCH mixtures of crotyl and methylvinylcarbinyl broCHaCHzCH=CH2 /I I1 62 % CHaCH HCCHa mides by the formation and hydrolysis of the Grig30% 7% nard reagents of these bromides or by treatment of the bromides with zinc in alcohol. Recently CHaCHBrCH=CHn zn? we were able to show that rearrangement to an Methylvinylcarbinyl bromide equilibrium took place during the preparation and The same butene mixture was obtained from all hydrolysis of the Grignard reagents of these of the bromide mixtures. bromide^.^ It is the purpose of this paper to present evidence that an allylic rearrangement to Experimental Part a different equilibrium takes place in the analoThe preparation of mixtures of crotyl and methylvinylgous process of reducing the bromides with zinc, as carbinyl bromides was carried out as previously described.& None of the products used in this work contained butyl shown below. We have treated various mixtures of crotyl and bromide. Carius analyses gave values within 0.15 of the calculated value of 59.20% Br. The refractive indices of rnethylvinylcarbinyl bromides with zinc in alcohol the bromide mixtures and the corresponding compositions and have analyzed the resulting butene mixtures are given in the Table of Results. by the dibromobutane reaction rate r n e t h ~ d . ~ The conversion of the bromides to butenes was carried
12"
(1) This work was accomplished with the aid of a grant from the Board of Research of the University of California. (2) Young and Prater, THISJOURNAL, 64, 404 (1932). (3) Young, Winstein and Prater, ibid., 68, 289 (1936). (4) (a) Dillon, Young and Lucas, ;bid., 82, 1983 (1930): (h) Young and Winstein, ibid., 68, 102 (1936).
out in the same apparatus used for the preparation of the Grignard reagents.' The bromides were dropped into zinc dust in boiling aqueous alcohol, the evolved butene (5) Winstein and Young, {bid., 69, 104 (1936). ( 6 ) Young, Prater and Winstein, ibid., 86, 4908 (1933).
