/?-PHENYLETHYL ESTERSWITH POTASSIUM AMIDEIN LIQUIDAMMONIA
March, 1945
TABLE I" ALKAMINE ESTER HYDROCHLORIDES, CsH6CH(A)COOCHr C (CH&NH (B).HCl Molecular formula
A
B
CsHr CsHr CsHs
tr-C:H, n-CrH, n-CrHrI
CsHs CaHs
CsHr
rr-CsHii i-C4Hs i-CsHiI
H H CzHs CzHs CzH,
n-CIH, n-CIHp n-CaH? n-GHs n-CaHl:
M. p., OC. (uncor.)
CrrHnOzNCl 158-159 CziHroOzNCl 173-174 CzrHirOzNCl 117-118 C ~ H i r 0 z N C l 100-101 CziHaoOzNCI 156-157 CzaHirO&CI 141-142 CIIHZ~OZNCI 112-113 CI~H~SOZNCI126-127 CIIHZ~OZNCI 115-116 CisH3oOzNCI 109-110 CroHirOrNCI 108-109
CI analyses, % Calcd. Found 9.80
9 .78
9.43 9.09
9.41
8.78 9,83 Y .OY
12.41 11.83 11.30 10.81 9.96
9.07 8.75 9.44 9.12 12.61 12.00 11.46 10.96 10.21
This table contains only the amino alcohol ester hydrochlorides which were readily purified by recrystallization.
[CONTRIBUTION FROM
THE
409
A heavy red oil sank from the ether to the bottom of the aqueous layer. A sample of this oil, on being seeded with crystals of a previous preparation of the hydrochloride of 8-methyl-8-mono-n-amylaminopropyl diphenylacetate, crystallized within a few minutes. The remainder of the oil and the aqueous layer were made basic with sodium hydroxide solution and extracted with isopropyl ether. Dry hydrogen chloride was passed into the isopropyl ether solution, precipitating a heavy oil, which crystallized within a few minutes, on being seeded. The product,
[email protected] diphenylacetate hydrochloride, was purified by recrystallization from acetone and anhydrous ether.
Summary
X series of hydrochlorides of @-iiiethyl-~-mui~ualkylaminopropyl phenylacetates, diphenylacetates and phenylalkylacetates is described. RECEIVED SEPTEMBER 12, 1944
RICHMOND, VA.
DEPARTMENT O F CHEMISTRY, DUKE UNIVERSITY]
@-Eliminationand Other Types of Reaction with Certain p-Phenylethyl Esters and Potassium Amide in Liquid Ammonia B Y CHARLES R. HAUSER,JOSEPH
Although the carbonyl carbon or a-hydrogen in the acyl portion of carboxylic esters generally enters into reaction with bases, the a-carbon or 0-hydrogen in the alkoxy portion is also capable of reacting. These four vulnerable positions of esters are indicated by asterisks in the following general formula.
e. SHIVERSAND PHILIPs. SKELL with esters of simple aliphatic alcohols, although olefins are produced on pyrolysis of certain of these ester^.^ With esters of alcohols having sufficiently activated /?-hydrogens, however, /?elimination is readily effected by bases. 0Nitroethyl acetate, for example, forms nitroethylene even in the presence of bicarbonate. CH~COO--CHZCH~NOZ +CHsCOOH
I
H *-C-C*=O
Keactions involving the alkoxy portion of esters would be analogous to those exhibited by alkyl halides. Actually several substitutions at the a-carbon, in which the carboxylate group of the ester is replaced by the attacking base, have been observed.' 0-Elimination, which involves the removal of the @-hydrogen as a proton accompanied by the release of the carboxylate ion to form an olefin,2has apparently not been observed
+ CH*=CHNO*
In the present investigation @-eliminationhas been realized with certain /3-phenylalkyl esters and potassium amide in liquid ammonia. Although 0-phenylethyl benzoate exhibits with potassium amide the carbonyl carbon reaction to form benzamide and /3-phenylethyl alcohol, 0-phenylethyl mesitoate in which the carbonyl group is hindered undergoes mainly @-elimination to form styrene and niesitoic acid.j
-", -----+
( I ) These include the reaction of methyl bmzonte with sodiiini AI~.~-CO~CH~CHIC~H~ methoxide t o form dimethyl ether [ A d i c k e , B w . , 66, 1904 (1933). A~w-COOH CsHbCH=CHp - -~ llaynani and XloElvain, IS JOUHNAL, 60, 813 (1!138)],the reactiriii common with eaters of ~ l r l o ~ i r n tfor . ~ . er;aniplr, aldoxime acetates. o f dimethyl, diethyl or dibutyl phthalate u i t h sodium phenoxide 1 0 especially t h r anti isomers, the reaction Iieing elTecteil by tertiary form the corresponding alkyl phenyl ether [King and Wright, J . . 243tl amines or alkali: bce Haurer and Jordan, Tirrs J ( i i 1 n x ~ i . 57, ('hem. S O C . , 1 l(i8 (IR:i!l) 1, the reaction of methyl benzoate or acetate 1 l!t3.i); Vermillion and liauser. ihid., 63, 1227 I l!ll I ) , Vermillion r$ith triiuethylaniine t o form the telrariiethylamm~,iiiiiiriiun [Will. s r ~ d IIauser, J . O v s . Chci,r., 6, R I U t l ! l 4 l ) . .t,,tter aiid Kdhn, B r r . . 35, 2757 (l!J(Y2); Hammelt aiid Pflugel-. (3) See Hurd "Pyrolyiis of Carbon Compouiids," Chemical Cata'CHIS I V U K N A L , 66, 4 0 i Y (1$J3:3)1. the alkylatiou o f mono-substituted log Co., New York, N. Y., 11320, pp i10-931; Norrii and Rigby, inalonic esters with diethyl carbonate t o form di-substituted malonic THISJ O U R N A L , 5 4 , 2097 (1932). esters [Wallingford and Jones, ibid., 64, 578 (1942)l and the S O (4) Schmidt and Rutz, Ber.. 61, 3112 (Iil'?8), H a i s a n i Riley, called abnormal acetoacetic ester reaction of benzyl or allyl acetate Chem. K E Z ' 32, , 408. 411 (1943). in the presence of sodium to form the ester of @-phenylpropionicor (i) @-Ulimiiiation wa$ realizer1 also with ,!-phr:nyl-ii-lnityl inebitoallylacetic acid [l'seou and \Vang. J . C h i i i r s c Chem. Soc , 6, 221 u t e (b. p. 176' a t 3 mm.) hut with this ebtcr, iii uliich the @-hydrogen ( 1 9 3 7 ) ; Bacon, A m . Cirrm. J . , 33, 08 (190,7)]. I n the latter reacic wmewhat deactivated by the @-ethylu r o u p . tlic rnrl,onyl carl,c,n tion the ester anion is a h s m r i l to be formed a s in t h e ordinary acetoi i i i n iiriii Carbonyl Carbon > /3Hydrogen > a-Carbon. I t should be mentioned that substitution a t the a-carbon to form the airline was realized only to a very small extent with P-phenylethyl acetate and not a t all with 6-phenylethyl benzoate or mesitoate. 16) See Hauser and Hudson. "Organic Reactions." Roger Adarns, Editor-in-Chief, John Wilry and Sons, Inc., New York, N. Y., 1942, chapter I X . (7) An intramolecular mechanism in which t h e negative end of the ester anion removes the #-hydrogen t o form directly t h e acetate ion rind styrene apparently does not operate, since excess amide ion is required t o produce styrene. (E) Judging from the relative rates of alkaline hydrolysis of the riirrehponiling ethyl esters, the carbonyl carhon should be only onei e r i l l i i i , reirctive in the benzoate a %i n t h e acetate See Harnmett, '8'Iiy.tv;sl Org,inic < ' I V U I ~ . I ~ > \1r(;r;tw-lltll H
