JANUARY, I 895.
VOL. X V I I .
No.
I.
THE JOURNAL OF T H E
AMERICAN CHEMICAL SOCIETY. ON THE BEHAVIOR OF ALLYLflALONIC, ALLYLACETIC, AND ETHYLIDENEPROPIONIC ACIDS WHEN BOILED WITH CAUSTIC SODA SOLUTIONS. CONTRIBUTIONS TO T H E KNOWLEDGE OF PROPYLIDENEACETIC ACID.' B Y JOHN G . S P E N Z E R . Received October 16, 1894.
D
U R I N G the preparation of hydropiperic acid, Fittig and Buri,* in 1883,discovered that in the reduction of piperic acid by nieans of sodium amalgam, two yery different isomeric hydropiperic acids were formed, according as the reducing fluid was kept almost neutral,, or allowed to become strongly alkaline by not adding acid. I n the first procedure they obtained the already known and now designated (Y hydropiperic acid, while in the second process together with the (Y acid, larger or smaller quantities of the new isomeric /3 hydropiperic acid appeared, which seemed to have been produced from the (Y acid through the agency of the caustic soda formed in the reducing fluid. I n fact it was proven experimentally, by heating the (Y hydropiperic acid, with caustic soda on the water-bath, that p hydropiperic acid could be obtained. Weinstein3 and Regel' were induced by Fittig to examine the two isomeric acids further, and because of its behavior on substituting broniine and hydrobromic acid as also in the oxidation with potassium permanganate they came to the interesting con1 Read before Section C.. American Association
lyn,N. Y . , August
20, 1%.
Chem., 116, 1 7 1 . Ibid. 1 2 7 , 31. 1 Bo-. d . Chem. Ges., ao, 414. 2 Atin. 8
for Advancement of Science, Brook-
2
THE BEH;TT:IOK OF , ~ I . r , ~ ' I ~ ~ l . ~ I . ( - ) ~ * I ~ ~
J O H T G . SPEN%I-C H ,--CH =C H--C C) 0H /I hydropipc-ric acid ( (Y /j) Other such displacements of the double lionti> of union through the agency of alkalies and even by boiling Ivater \ v e x soon found. Baeyerl observed, that the r P 5 diliydrotereplitli~lic acid, became tlie d'.j dihydroterephthFlic acid. when boiled with water, and the latter, in turn, \rtien boiled with caustic sotla. produced the d1.4dih~droterephthalicacid, accordiiig to the following scheme : CH--CH HOOC-CH( \CH--COOH CH=CH/ Ti'.j dihydroterephthalic acid. CH--C H,~ c H --coo H H O O C - C H \~C H Z C I l / '
'
-, since pure propylideneacetic acid can produce 110 lactone. Such acids a s have been prepared and described under the iiaiiie of propylideneacetic acid are no homogeneous bodies. I t was not until the writer, i n July, 1892,procured the acid in its crystalline form by boiling ethylidenepropionic acid with caustic soda; and Mackenzie,' in February, 1893, secured it after the method of Komnenos that pure propylideneacetic acid had been made and characterized. Boihig a j Ethylidcne@pionic .4cid with Sodium Hydyoxide.Sodium ethylidenepropionate, in portions of ten grams each, was boiled with thirty-three grains of sodium hydroxide dissolved in 2 g j grains of water for fifteen hours i n a copper flask connected with a return condenser. T h e cold alkaline solution was now acidulated with ether, the ethereal extract distilled with steam until the distillate came over perfectly neutral ; tlie milky acid 1
2 b 5
R P ~d .. ~ / , r i i i . G E J .22, . 494, Ibid. 23, 6 1 6 . I b i d , 14. y q . Ibid, 14> 2.600. 4 Ihid, PI, 2,7ry. 3 Ibid. 26, y r j . 8 Hey. ti. r h e i u GeA.>1 4 , gog. Ibid, 2 5 5 , 33. I>issertatioti.Strasshurg. 1894.
ALLYLACETIC, AND ETHYLIDENEPROPIONIC ACIDS, ETC.
I9
distillate was neutralized with barium carbonate in the cold, filtered, and evaporated to dryness. From the liquid remaining in the distillation flask the /3 oxyvalerianic acid was obtained (see fi oxyvalerianic acid). To separate the ethylidenepropionic acid and expected propylideneacetic acids, the dry barium salt was repeatedly extracted with hot alcohol and filtered hot each time ; the barium salt remaining undissolved was perfectly white and proved to be unaltered barium ethylidenepropionate ; it was through double decomposition with sodium sulphate changed to the sodium salt, in which form it was again boiled with caustic soda. In the alcohol another barium salt had been dissolved ; on distilling off the solvent a light yellow-colored, amorphous varnish-like mass was left behind ; this was supposed to be the barium salt of the newly formed a P acid. Toremove every trace of /s y acid from it, the barium salt was decomposed with sodium sulphate forming the sodium salt, and this mixed with a quantity of dilute sulphuric acid (one volume concentrated sulphuric acid and one volume of water), corresponding to five times the amount of organic matter present, plus a sufficiency to neutralize the sodium of the sodium salt and heated in a flask almost to boiling, with constant agitation for fifteen minutes, then mixed with a like bulk of water and boiled for thirty minutes. Allowed to cool, the acid solution is extracted with ether, the ethereal extract again rapidly boiled with some water, and a few drops of dilute sulphuric acid to again change into lactone any oxy acid, which may have been formed, rapidly cooled off, sodium carbonate added to an alkaline reaction, and the lactone at once shaken out with ether. T h e alkaline solution free from lactone was again acidified, extracted with ether. and the ethereal residue distilled with steam, the acid distillate neutralized with sodium carbonate anew, and the sodium salt obtained, again treated with sulphuric acid as above. T h e entire operation was repeated until no more lactone was formed ; this was accomplished after repeating it two or three times, when every trace of /s y acid had surely been removed. Propylideneacetic acid : CH,- CH,-CH = C H -COOH. After no more lactone could be detected in shaking the alka-
XI
JOHN
(;.
SPI:SZIIR.
'rm
H I ~ A Y I O KOF .II,I,YI,MALONIC,
line litquid after boiling with sulphuric acid, the solution W:IS acidified and distilled with steam. and from the acid distillate tlie sotliuiri or calciuiii salt of the IY /j acid produced. On decoiii. posiiig tlie sodium salt ivitli sulphuric acid, or the calcium salt with ill-drochloric acid i n a nnrro\v tube, the pure (Y /3 acid \vas o1,tairietl as an almost colorless oily layer ; it was clrawn off,tile last portioiis extracted with ether, am1 the ethereal solutions dried 1))- iiieans of dried sodium sulphate or calciuin chloride, filtered, and tlie ether e\raporated, leaving a colorless oil, xvliich congeals in a freezing mixture at once atid reiiiaitiing solid : " C. indefitiitely in ice-water, since it inc1t.s at 7:' to 8 In cold winter weather it is extreinelJ- easy to obtain the acid perfectl). pure arid of the correct iiieltiiig point. Tile ;tcid iroiti the ethereal extract is poured into a watchglass and placed i n a desiccator at :L low temperature ; it then solidifies in flat rlioitil~ohedraltullles or leaves, which can, with the aid of :i cold platinum wire, be brought upon a piece of filter paper. to there give up tile last traces of moisture, remainiiig behind as flat, glistening crj,stals, T h e acid is therefore the i~ p aci(1. correspouding to the etliylidetiepropionic acid ; its tiieltitig-poiiit. coinpared with x specimen of the acid subsequentlj. prep:iretl. after tlie niethotl of Komnenos, t which was purified niid crystal!ized i n a like riianrier, gave the following resjults. X specimen of each was placed on the bulb of the same thermometer arid plunged into a freezing mixture for a minute aiid tlieii into cold water, the temperature of which was gradually raised. At 69" C . they both remained solid. Xt 7' C . likewise so. At 74" C . both samples began to melt slightly. At 7.;' C. both were about half melted. At 8" C. only a small quantity of each still remained solid. At x i o C. both were completely melted. The melting-point determinations were made by placing the acid in thin-walled melting-point tubes two mm. in diameter, m d closed at both ends : this allowed of a repetition of the estii A UII.
C h c m . , 218, 166.
ALLYLACETIC, AND ETHYLIDENEPROPIONIC ACIDS, 8°C.
2I
mations without any danger of loss by evaporation or inaccuracy from the absorption of water. During some recent work on propylideneacetic acid by the Komnenos' process, Mackenzie' found the melting-point to be g+"-108"
c.
It is much more di5cult to obtain the solid acid of a constant melting-point in summer; to this end the following method was used : T h e acid freed, as much as possible, from ether and water, contained in a small flask held horizontally, was moved backwards. and forwards through a water-bath of 65' C., in order to remove the last traces of ether. T h e flask was then closed with a stopper and calcium chloride tube, and plunged into a freezing mixture of ice and salt, in such a manner that the acid congeals on one side of the flask ; the flask was now placed upright in a vessel of ice-water for an hour ; the mother-liquor draining out was poured off; finally the crystalline cake was itself slightly warmed, so t h a t the last low melting portions of the acid percolated out what remained congealed in a freezing mixture completely and did not remelt in ice-water. Pure propylideneacetic acid becomes solid at oo C.; if the melted acid be placed in ice-water, it solidifies in half an hour. If a crystal of the acid be dropped in, it congeals at once. T h e smallest quantities of water or ether have a decided effect on its melting-point. At the ordinary temperature pure propylideneacetic acid is a mobile colorless liquid with a faint, pleasant odor of acetic acid. It is so qolatile, that even at 45' C. it passes over with the ether vapors, and in summer a considerable loss is not to be prevented when working with this substance. About sixty per cent. of the ethylidenepropionic acid is converted into propylideneacetic acid by boiling with caustic soda. For analysis the acid melting at ';7 to S i o C. was used. I. 0.2716 gram acid gave 0 . 1 9 1 5 gram H,O, and 0.595 gram
co,. 2.
co,.
0.2965 gram acid gave 0.2125 gram H,O, and 0.6508 gram
1 Dissertation,
Strassburg,
I&&$.
22
J O H S G . SPENZER.
THE REHAVIOR OF .41LYLMALONIC,
a.
Calculated for C,H,O,.
c .......... 60.00 €1
..........
8.00
€~OlIU I
2
j9.75 per cent. 7.84
j9.86 per c e n t . 7.96 ''
Salts ofPyojylideizeacefic Acid.--Barium Salt. T h e barium salt of propylideneacetic acid is very characteristic ; it was prepared by neutralizing propylideneacetic acid with barium carbonate suspended iii water ; the neutral solution was boiled, filtered, and evaporated to a pellicle ; after cooling, the pellicle was removed froni the surface of the solution and the liquid placed in an icechest (for when allowed to evaporate a t the ordinary temperature a sticky inass only separates o u t ) to undergo a very slow evaporation. After soine weeks the salt is deposited i n needles grouped to rosettes ; these were waslied and subjected to analysis. T h e salt contains considerable water of crystallization, but effloresces easily, becoining anhydrous in a desiccator over sulphuric acid. I . T h e salt pressed between filter paper and allowed to remain in ail ice-chest on a piece of filter paper over night, was on the following morning neighed into an open crucible, and allowed to remain i n a desiccator to constant weight. 0.2102 gram lost 0 . 0 1 7 0 grain H,O or 8.10 per cent. 2 . T h e pressed salt was, after remaining for fifteen minutes on a piec- of filter paper in the ice-chest, weighed into a n open .id allowed to remain to constant weight in a desiccrucih' cat. ,6470 grain lost 0.1028 gram H,O or 15.88 per cent. ;he pressed salt was placed for twenty-five minutes in the ,: !. it 14' C. and then treated as above. 0.2493 gram lost 0.0203 gram H,O or 8.14 per cent. 4. 0.1932 gram of the salt dried in a desiccator gave 0.1335 gram BaSO,, 0.0785 grain Ba. Calculated for (C,H;O,),
Ba.
40.89 per cent. Ba.
Found.
40.63 per cent. Ba.
I t follows froni these determinations that because of the disposition of this salt to effloresce, it is impossible to make a n exact estimation of the water; the difference in amount seems to depend on the temperature at which the crystallization takes place.
ALLYLBCETIC, AND ETHYLIDENEPROPIONIC ACIDS, ETC. 23
It was found impossible to examine the crystals optically; one can only see that they are tables with end faces, but to which system they belong can not be said. T o observe the deportment of the crystallized salt at a higher temperature, a portion which had crystallized out in the icechest was placed together with its mother-iiquor in a stoppered vessel and allowed to remain several days at a temperature of 20' C.; a part of the crystals were thereby dissolved ; the other portion, however, remained crystalline and did not become sticky. Calcium Salt. T h e calciuiii salt was made by neutralizing an aqueous solution of the acid with calcium carbonate in the cold ; the solution boiled, filtered, and evaporated to a pellicle ; on cooling, the salt crystallized out in moderately long, flat, glistening prisms; they were collected on a platinum cone, washed, dried, and laid 011 filter paper for twelve hours at 6" C. T h e salt gives off all its water of crystallization in a desiccator. 0.4155 grain gave 0.098 j gram H,O. Calculated for (C5H101), Ca+4H1O. 23.22 per cent. " 0 .
0.2263 gram of salt dried Calculated for (C5H101)1 Ca.
at
Found.
23.71 per cent. 100'
16.81 per cent. Ca.
C. gave 0.1298 gram CaSO,. Found.
16.87 per cent. Ca.
T h e calcium salt crystallizes much easier than the barium salt, since it can be obtained at a temperature of 16" C. in nice prisms, while the barium salt always becomes sticky at this temperature. Calcium propylideneacetate like the barium salt is easily soluble in water and alcohol. Projylideneacetic acid dibromide .
/3 dibromvalerianic acid. a /3 pentinic acid dibromide. CH, -CH,-CHBr -CHBr-COOH. To further characterize the acid, the bromine and bromhydric acid addition products were made. To prepare the dibroniide, the vessels and reagents used were carefully dried. T h e acid was dissolved in a little carbon disulphide and then with exclusion of air the calculated amount of bromine in a ten per cent. carbon disulphide solution was added through a dropLY
24
J O H N G. S P E N Z E R .
T H E BEHAVIOR O F ALLVLhIALONIC,
per funnel-tube. A violent reaction was not noticed even at the commencement, the decolorization being slow and incomplete. T h e experiment was conducted in diff used daylight. After a small excess of bromine had been added, the whole was cooled off and allowed to remain quirt for twenty-four hours ; the most of the carbon disulphide was then removed by aspirating a current of dry air through the bottle ; the remaining solution was placed on a large watch-glass i n a desiccator, :tiid the disulphide entirely renmved by frequent stirring with a glass rod. T h e desiccator placed in a refrigerator soon caused the dibroiiiide to crystallize out i n large leavcs. After the disulpliide had been completely removed by alternate stirring, and evacuatioii of the desiccator, the solid dibroniide was dissolved in the least possible quantity of petroleuiii ether, and the solution allowed to stand in a corked test-tube for several hours. Here the dibroiiiide was deposited in rosettes of flat prisms on the sides of the tube. T h e niother-liquor was rapidly decanted ant1 the crystals washed two or three times with cold (0' C . ) petioleuiii ether, and again crystallized out of the latter, when the preparation was considered pure. T h e dilxoiiiide seeins not adapted for crystallographic study ; the crystallization is probably iiionos,mmetric ; it melts without coloration at 56" C . ; it is very soluble in carbon disulphide aiid benzene ; in petroleuni ether it is easily soluble. 0.2040 gram of the dibroiiiide dried in a vacuum gave 0.2957 graiii of XgBr = 0 . I 2 j 8 gram Ur. Calculated for C6H,13r,U,.
61.54 per c e n t . B r .
Found.
61.68 per c e n t . Br.
fi Broinvalerianic acid. CH,-CH,-CHBr
--CH,-COOH. T h e liydrobroniic acid addition product of propylideneacetic acid was prepared as follows : T o one volume of the pure acid contained in a small cylinder having a well-ground stopper, one and a half volumes of hydrobromic acid saturated at oo C. were added ; on shaking, a clear solution resulted ; it was allowed to reniaiii quietly for twenty-four hours at the ordinary teniperat u r e ; the monobromide had now risen to the surface of the hydrobromic acid as a light brown-colored layer. T h e cylinder was now vigorously shaken from time to time, to bring any
SLLYLACETIC, AND ETHYLIDENEPKOPIOKIC ACIDS, ETC. 2 5
unaltered propylideneacetic acid which might be dissolved in the monobromide, into intimate contact with the hydrobromic acid. After this occasional shaking had been continued four or five days, the contents of the cylinder formed two distinct layers; the reaction was ended and all the propylideneacetic acid had been quantitatively changed into fi broinvalerianic acid. T h e cylinder, still stoppered, was now placed in ice-warer to cause the new acid to solidify, this, however, did not occur. It was then placed in a freezing mixture of ice and salt, and on agitating slightly, the inonobromide at once congealed to :I mass of fine needles lying on the surface of the hydrobromic acid. T h e cylinder stood for fifteen hours at a temperature of 15' C . ; then the crystalline cake was broken through with a glass rod, distributed through the hydrobromic acid, and brought into a platinum cone where it was allowed to dry, being washed with small successive portions of ice-water, in order to remove the greater part of the mineral acid. T h e contents of the cone were now brought upon a watch-glass and placed in a vacuum over sulphuric acid and potassium hydroxide ; a dry sandy-white substance resulted, which was powdered and recrystallized out of petroleum ether. So produced, the 6 bromvalerianic acid is, after drying, perfectly pure, as the analysis proves. 0.233 grain of the substance dried in a vacuum gave 0.2410 gram AgBr. Calculated for C,H,BrO,.
44.20per cent. Br.
Fouiid.
44.20 per cent. Br.
bromvalerianic acid melts at 59' to 60" C., the melting-point not altering in the least by repeated determinations on the same sample. I t dissolves readily in ether, chloroform, carbon disulphide, less easily in benzene and petroleuni ether, and is almost insoluble in water of oo C. If the cold, saturated solution of the inonobroinide in petroleuiii ether be allowed to evaporate spontaneously it crystallizes out in beautiful, colorless, eight-sided prisms. T h e crystals set up after Nautnann's system give the following crystallographic measurenients :
26
THE BEHAVIOR OF ILLYLMALONIC,
JOHN G. SPENZEK.
j3 BROMVALERIANIC ACID. Crystal system
: 11
Observed forms: m
={
IIO
‘
A=
Mouosymmetnc
4688 I o 4900 1 = 79“ j8’55’’ I
1 cc P,
a=
[
I 1 0 0 ) 30
Pm, b
=IOIO
)wPm,
V = ~ O I I ) P Wd, = ( i o I ) + P w , e = = [ I o ~ ) - P c c .
d T h e crystals are mostly two to five mm. long by one to two mni. wide, and possess a valerianic acid-like odor.
+
Some crystals are minus [io11 P w , as also [ r o o ] GO P w , while [IO;] - p w was only observed once. T h e faces were almost always smooth and polished, giving excellent reflexes. T h e following angles were measured and calculated : Measured
r : r = (011) : (011) = *5rc 31’ a : in = (100) : ( 1 1 0 ) = “55‘ 20’ 30” r : rn = (011) : (im) = *99- I ’ m : m = (110): ( I i o ) = 110“ 43’ m : b = (110) : (010) = 34‘ 47’ r : P = (011) : (010) = 64‘ 6‘ a : b = ( t o o ) : (010)= 89” 58‘ a : d = (100) : ( ~ o I )= 99- 2’
Calculated
......
...... ......
I10
41’
31- 39’ 30” 6 4 ’ 14’30” 90‘ 99c 121
ALLYLACETIC, AND ETHYLIDENEPROPIONIC ACIDS, ETC. 27 Measured.
Calculated.
r : m = (011) : (110) = 74O 2' a : e = (100) : (101) = 61O 59' r : d =(IOI) : (101)= 36O 33' r : m = (011) : (110)= 63" 33'
3 6 O 29' 63O 28'
r : d = (011) : ( l o r ) = 3 P 8' d : m =(roo') : (100) = 80° 1 1 '
31° 45' Eao 48'
74O 26' 62O 44'
A cleavage could not be found. T h e plane of the optical axes stands at right angles to the klinopinacoid arid is only slightly inclined towards the orthopinacoid. Obtuse bisectrix = b axis. /y Oxyvalerianic acid, CH,-CH,-CH (OH)-CH,-COOH. T h e acid mixture from the treatment of ethylidenepropionic with caustic soda was not completely volatile with steam. T h e residue left in the distillation flask, after the ethylidenepropionic and propylideneacetic acid had been driven over, had a strong acid reaction and gave up a yellow oil when shaken with ether. It was purified by dissolving in ether and precipitating with petroleuin ether as a thick colorless liquid. This syrup could not be solidified either by allowing it to remain in a desiccator or at a temperature of 18' C. for several hours, aided by frequent stirring with a platinum wire. A portion of the acid, which had been prepared from the perfectly pure barium salt, was dried in a desiccator to constant weight ; it then presented an absolutely colorless liquid, which, when put into a narrow test-tube and placed in a freezing mixture, would not become solid with frequent stirring by means of a platinum wire. At best it remained a colorless molasses-like liquid, although the barium salt from which it was obtained as well as the acid itself, as far as purity is concerned, left nothing to be desired as the analyses show. 0.2745 gram obtained from the pure barium salt contained in a platiriuiii boat and dried in a desiccator gave 0.2073 gram H,Ofo.5105 gram CO,. Calculated for C,H,,O,.
................ 50.85 per cent. H ............... 8.47 '( C
Found.
50.72 per cent. 8.39 "
fl oxyvalerianic acid is easily soluble in cold water, ether, benzene, and in chloroform ; in carbon disulphide and petroleum ether it is insoluble.
28
JOHS G . S P E X Z E K .
T H E I~F:H.\\-IOR OF
.xr,r,\ir,xmosrc,
Froiii forty-five grams of ethylidenepropionic acid, which was boilecl with caustic soda, 1 6 . j grams or thirty-six per cent. of /j oxyvalerianic acid w a s producwl . S d f s qi /j Oq~z~alci-l'aiil'r .Icid.--Calciuni Salt. T h e still y d lo\v-coloretl acid was tliiuterl nith water arid lieatcd o n tlie water-bath uiitil tlie mixture reacted neutral : it was then filtered and the yellow-colored filtrate decolorized with aiiiiiial charcoal ; the filtered solution was now evaporated until a pellicle fornietl on the surface arid ivas theii nllowed to cool ; the pellicle was dissolved aiiti alter reiiiaining :it the ordinary temperature for sonie tiiiie there was depositetl oii the bottom of the vessel a collection of ivhite opaque Tvarts of porcelain-like appenrmce, \vliich, ivlien poivderetl and dried i i i the air, \vas malyzetl. I . 0 . 4 3 gram of air-dried salt lost 0.0263 grarii H 7 0 at 17.5' C. Calculated for ( C 5 € I s O z ) 3Ca+H,O
6.16 per cent. H,O. 2 . 0.1889 grain ariliydrous Calculated for ( C , H , , 0 R ) 2C a . 14.j 9 per ceiit. Ca.
l:~~~11111.
6
I?
per c e n t .
salt gave o . q i j grain CaSO,. I:oull~i.
r j . , ; ~per cent.
T h e salt retains its water of crystallizatioii verb- tenaciously and gives i t lip when licated for some time at 1 7 j 3 C. At 180" C. it begins to melt ant1 acquire a yellow tint, whereby it loses considerable in weight and at 200' C. a ellon on transparent iiiolten mass filled with bubbles results, with ail increase in the ainouiit of decoinposition, which began at ISO" C. The salt is quite soluble iii water and insoluble in alcohol. Still tlie aqueous solution, to which three voluiiies of absolute alcohol has been added, reniaiiis perfectly clear a t first, oiily becoining cloudy after the lapse of some hours, and after a longer period the salt is deposited as a sandy iiidistinctly crystalline mass. Treatetl witli alcohol on a slide and examined uridrr the iiiicroscope the followiiig was observed : The precipitate consists of small, mostly irregularly formed, double refracting leaves, stretched a t tinies in one direction, and which present an oblique obliteration of light, parallel to this principal direction of development. Because of this oblique obliteration the crystals probably belong to the monoclinic system. Barium Salt.-The bariuiii salt was prepared in exactly the sanie manner as the preceding, by warm iieutralizatioii of
ALLYLACETIC, .4ND ETHYLIDENEPROPIONIC ACIDS, ETC.
29
barium carbonate; the solution evaporated to a pellicle, was allowed to cool, the pellicle not dissolving ; after about an hour it became cloudy, and deposited small, fine needles, which gradually accuniulated on the bottom of the beaker as a sandy crystalline mass. This crystalline inass treated with alcohol and examined under the microscope, showed a colorless, strongly double refracting homogetieous number of crystals, gfouped to a half ball ; they were tables of rhombic or right angular form, with an oblique obliteration and were, therefore, probably monoclinic. 0.1983 grain of the air-dried salt lost o.oog3 gram H,O at 105' C. and gave 0.1 193 gram BaSO,. Calculated for (CSH,O,), Ba+H,O.
H,O .............. 4.63 per cent. Ra ............... 35.22 "
Found.
4.67 p e r c e n t . 35.36 '(
At 105' C. the salt melts without decomposition to a colorless transparent mass ; even, on the water-bath, when covered with a little water a thick syrup results. It is insoluble in alcohol. Silver Salt.-The silver salt was obtained by the double decomposition of a warm concentrated solution of the calcium salt with silver nitrate, as slightly violet-colored crystals or a powder according as it separated out rapidly or slowly. When recrystallized from hot water it is nearly white and is but little affected by light. 0.1037 gram of the salt dried at 50' to 55' C. gave in the conibustion 0.0497 gram Ag.; 0.1018 gram CO,; ando.03go grain H,O. Calculated for (C,H,O,)Ag.
............. 48.00 per cent. C ................ 26.67 H ................ 4.00 '( Ag.
..
Found.
47.93 per cent. 26.86 " 4.27 ('
Microscopically the crystalline powder appeared to be fine, flat, at times, corroded needles, which had an oblique obliteration in their long direction. Boililig fi Oxyvaleriaiiic An'd with S o d i m Hydroxide.--For this very interesting experillietit 6.240 graiiis of calcium fi oxyvaleriatiate (representing five grams of acid) was used ; through double decomposition with sodium carbonate sodium fi oxyvalerianate was formed and this boiled for thirty hours in a copper flask connected with a return condenser and containing I 7. I grams, of sodiurii hydroxide in 154grams of water.
30
JOHX G . SPEKZEK.
THE BEHAVIOR OF XLLYLM.I~LONIC,
After cooling, the solution was acidified with sulphuric acid and extracted with ether. The ethereal residue rapidly boiled with water and a few drops of dilute sulphuric acid, to change any y oxy acid present (which could have originated froin the p oxy acid with ethylidenepropioiiic acid and valerolactone as intermediate steps) into lactone, was then inade slightly alkaline with sodium carbonate, and shaken out with ether; nothing was taken up by the latter, consequently, the presence of y oxy acid must be excluded. The alkaline solution, after the ether had been removed, was acidulated with sulphuric acid and distilled with steam until the distillate passed over the neutral. T h e unaltered p oxy acid remained behind in the distillation flask, which, when shaken with ether, allowed of its removal from the contents of the same ; it was converted into the calciuiii salt, which ainounted to three and four-tenths grams or more than one-half of the acid originally employed. T h e acid distillate was neutralized with barium carbonate, but since the barium salts thus obtained do not allow a good separation with alcohol, they were converted into the sodium salts through the aid of sodium sulphate, and now the p y acid coiiverted into lactone by boiling with sulphuiic acid, made alkaline with soda solution, the lactone was shaken out with ether, and characterized by boiling with barium hydroxide for thirty minutes, thus converting it into the barium salt of y oxyvaleriaiiic acid. After precipitating the excess of barium with carbon dioxide in the heat, the evaporated filtrate gave I .973 grams of an amorphous substance easily soluble in alcohol and water, from which it was deposited as a gummy mass, and proved in all its conduct to be the barium salt of y oxy acid. Finally by exactly precipitating with sulphuric acid in the heat, and adding potassiuin carbonate to the cold filtrate in a narrow tube t!ie valerolactone was obtained as a supernatant layer. T h e alkaline solution freed froin lactone was acidulated with sulpliuric acid and distilled with steam ; from the acid distillate through neutralization with calcium carbonate 0.94 gram of calcium propylideiieacetate was obtained, froiii which the acid itself was freed. After purifying i n the nianner already mentioned it melted at 7 t o to S i o C.
ALLYLACETIC, AND ETHYLIDENEPROPIONIC ACIDS, ETC.
31
I n the process of boiling with caustic soda, there was obtained from the /3 oxy valerianic acid : 56.6 per cent. of unaltered oxy acid. 21.26 per cent. of ethylidenepropionic acid. 14.64 per cent. of propylideneacetic, with a loss of 6.5 per cent. Distillation of the /9 Oxyvalevianic Acid.-A portion of the thick, almost colorless, acid was so distilled from a small distillation flask that it passed over slowly and in drops. As the boiling began, the thermometer with its bulb in the liquid indicated 190' C.; it was now raised until its bulb was just beneath the exit tube; it sank to 180' C., but rapidly rose to 190' C., where it remained constant for a short time, gradually rising to 195' C., and then to 200' C., where the principal portion went over, and finally to 203' C.; the last drops of the distillate were colored yel1ow;and a small tarry residue only remained in the flask. T h e distillate, which had the same empyreumatic odor as that from methylparaconic acid, was mixed with five times its volume of water and sufficient sodium carbonate to render it distinctly alkaline after a Vigorous shaking ; nothing could be extracted by means of the ether, consequently, the distillate contained no lactone and a conversioh of p oxyvalerianic acid into y oxy acid respectively y lactone had not taken place. T h e salt solution, free from ether, was now acidulated and distilled with steam, in order to separate the unsaturated acids from the oxy acid. T h e milky distillate was neutralized with barium carbonate and thereby the mixed barium salts of the volatile acids obtained ; as, however, these can not be satisfactorily separated with alcohol, the above-described process used to effect their separation when produced by boiling the oxy acid with caustic soda was employed and the P y acid separated as lactone from the a /3 acid ; the latter was characterized by means of its melting-point. From the residue of the distillation with steain a small amount of the B oxy acid could be extracted. T h e principal product in the distillation of the p oxyvalerianic acid was propylideneacetic acid ; only a small quantity of ethylidenepropionic was found, and a like small portion of oxy acid went over unaltered. T h e three isomers allylacetic, ethylidenepropionic, and pro-
THE BEHAI'IOR OF A L L Y I , M h L O N I C , ETC.,.\CIDS.
32
pylideneacetic acids, can, as the accompanying table shows, be easily characterized anti distinguished. But recently Fittig and Mackenzie' have for the sake of siinplicity, applied the terms y 6, p y . and a p pentinic acids to the allylacetic, ethylidenepropiorlic, and propylideneacetic acids, respectively. ~ l l ~ lacid, ~ ~ ~ Ethylideneprot pionic i ~ acid.
Free acid.
Fluid. boilingpoint 1 ~ 6 " - 1 8 j 'c.,
c h a r a c t e ristic
odor resembling that of valerianic acid.
Calciun, da,t,
Rarinnl
1 '
Propylideiieacetic acid.
~
Fluid. boilingpoint iy3a-Iy4' C. Solid nielts at ji-b:" C
'
I
Crystallize out of a hot saturated aqueous solution with one molecule of water in Rat pointed prisms, which a r e insoluble in alcohol.
Crystallizes O U of ~ the aqueous solution in the cold. with four molecules of water of crystallization Soluble in hot absolute alcohol.
Crystallize out of a hot saturated aqueous solution with one molecule of water in flat pointed prisms. Irisoluble in alcohol.
Crystallizes in the cold out of the aquebus solution with two and four molecules of water. Soliible i n hot absolute alcohol .
~
Gives with hydrobroiiiic bromvalerianic acid. This crystallizes out of petroleum ether in monoclinic I)risms with the following orms: . .
I acid ( 1 Blonobroniide.
Both acid5 produce the same i bromvalerianic acid with hydrobromic acid. Fluid and not solid at--16' C.
\
>
IJ P \+p,,--F2, melts a t Insoluhle in water, beconies liquid in water of 45'-50' C. aP,,,P
.-
j2-8'~.* -
-.
_-
risnis developed I
I: the direction of the C . I. I.. I.. E _. R ~ i d .
Thin four-sided I ily s o l u h I e in warm etroleuni monoclinic tables nieltin a t 58". ' e t h e r : fess so i n D i f f i c u 1t l v cold. M e 1 t i n gsoluble in petr& point65"; dissolves leum ether. 1 in water with a , gyratory motion Becomes fluid UII1 der water of 50'-
i
Dibromide.
i
,
WESTERN R E S E R V E U S I V E R S I T Y , M E D I C A L DEPARTMENT. C L E V E L A N D , OHIO.
1
..._-
Dissertation,Strassburg, 1%.
Monoclinic prisms melting a t 56', becoming liquid under waterof 15" C. Very readily soluble in petroleum ether a t t h e ordinary temperature.
