TXIBROMPHENOLBRO.1IIDE.
7
been received. Fifty-nine members oi the larger committee are therein recognized. Thirty-one voted for a table based upon 0 = 16 exclusively; two for H = I exclusively; and five for the simultaneous use o l both standards. To the last vote should be added that of the four members of the smaller committee, making nine i n all for the double table. Seventeen members refrained from voting. T h e vote, then, gives one more than a majority of the entire committee in favor of the olsygen standard alone, although the committee appointed by the Chemical Society of Paris in rgoo seems not to have been consulted. Copies of the report as drawn and agreed to were sent to England, France, Germany, Italy and Japan for sitnultaneous publication. It is therefore, in the opinion of Professors Thorpe, Seubert, and myself, too late to attempt any change for the current year. To withdraw, rewrite, and re-sign the report would involve too great a delay. l y e therefore ask for patience on the part of the larger committee, whose wishes will receive due consideration next F. \Y.CL-~RKE. Tear.
TRIBROMPHENOLBROMIDE : ITS DETECTION, ESTIMATION, RATE OF FORflATION, AND REACTION WITH HYDRIODIC ACID. BY 5 J LLOYD Received October z;, 1904
THEfollowing eupcriments form part of an investigation of the reaction between bromine and phenol, which mas undertaken with the object of improving Koppeschaar's method of determining the latter substance. T h e tribroniplienolbromicle used was prepared by 11-erner'sl recipe, recrystallized three times from chlorofoiin, and dried for three days over sulphuric acid in a vacuum: it formed goldenyellow crystals, melting-point I 19'. DETECTION.
ll'lien searching for a distinctive qualitative test for tribromphenolbromide, I found that ammonia, and chloroform solutions of many of the organic bases react with it to form colored products, a s follows : 1
Bid! Suc Clum
, 43. 3:'
(r%j)
6
S. J. LLOYD.
Aninionia Aniline Dirnethy laniline Paratoluidine Diplien ylaniine a-Naphthylamine ,'?-Naphthylamine Aniinoazobenzene
13rown. Deep red, turning inudtly. Slight darkening. Clear red Light red. Dark blue, turning purple. 1,iglit rose-pink, appears very slo\vly. nrown-red, appears very siowly ant1 gradually deepens. I'yriditie Light yAlo\v. Intense green, purple if concentrated. Benzidine Azoxyhenzene, Xetanitqaniline, Acetanilide, no change.
( t f these. aniline ant1 lxiizitlint. pi-oved most suitable as r e a p i t s : \v i tli trihroiiiph enol, t e t rabroiii pli e ii ol a ii t l 11e s a b 1-omplieiioq u i 1: 01 i e tliq- give no. color, whi!e \\-it11liromine \vatel- a n aiiiliiie solution is bleaclietl, and benzidine gives ;I seal-.brmvii, cjuitc tlistiiict from the g-reeii xvitli tribrornplieiioll~rtimitlc. The lieiizitline solution ni:iy lie pi-epared 11)- wariniiig 5 gr;iiiis of beiizidii?e sulpliate with 30 cc. i i f a I O per cciit. llotasli solution, c~ioliiig~estractiiig the 1)eiizitlinc with chloroform. ant1 filtering cui?' the ch!or;~iorm solutioii. 'I'liree (lrops of iliil; reagent give A clistiiict greeii Tvith I O cc. o f ;i solutioii contaiiiiiig I gram cif trib roiii pli cnolbroiii i tl e i I i a 1i t CY t I i cli lo ro io rni . Shaking the t ri h rc~iiil)lienolbioinitiesclut ion 11-i tl I tlecinormal iiim i l ~ i ~ ~ s ~ ~ l l ~ I i ; t t ~ before atitling tlie benziciiiit: i-eagyiit tlocs i i o t er fcre \vi tli tlie color reaction.
I:S'TI >l.i'rIo>;.
-.Is the reaction xvitli potassium icxlitle is oliviousl!. iuisuitnble i see page z o ) , a basis for the mtthotl \\.as sought in the action o f reducing agents : Belledict' states that zinc and h!-tlrochloric acid t u triliroiiiplienol, Init t1ot.s not aecin retlucc tril~romplieiiolbi-~:iilitle t o 11:LTe 111at1e an>- (1u an t i t a t iv e iiica sur eni en t s . .\ f t er e sper i iiieiit iiig ivitli sodium amalgam an(! ivitll magiiesimii, I fiiially tleciclecl in favor of po~w;deretl zinc aml sulpliiii-ic acitl. wliich are without action upoii tribroniphenol. lnit retiio8veoiie atom o i 1)romint. from tribruniplieiiolbromitlc. ljy tieterniiniiig the lmmiiiic i i i t h y solution ,liter retluctioii. it is tliiis 1)tissiblt: to calculate the ariiouiit c f ~rihroiiiplieiiolbromidtin the substaiice analyzed. 'l'lie tietail.; nf tlie iiietliocl are as follon-s : I lie trihro~iiphenolhro~iii~l~~ \\.;is placeti i l l ;i I .jo i'c. tlas!;, 20 CY P .
: A H , ~C.% i n a . (IjeliigN, i y y , : r ;
9
TRIBROYPHENOLBROSIIDE.
of alcohol (96 per cent.), 5 cc. S/4 sulphuric acid and a b u t
0.25
gram powdered zinc1 were added, and the flask heated on a waterbath until the whole of the tribromphenolbromide had dissolved and the solution had lost its characteristic yellow color. Excess of calcium carbonate was then added to neutralize the free sulphuric acid, and the alcohol together with most of the tribromphenol were distilled off on a water-bath ; the residue was extracted with three successive portions of hoiling water, 25 cc., 25 cc., and IO cc., respectively ; and in the filtrate, after cooling, the bromine was determined by X/IO silver nitrate with potassium chromate as indicator. Elank experiments with tribromphenol showed that no bromine was removed by this treatment. TESTAX.AI,YSES. Trihromphetiolbromide Gram
AgNOIcalc.
Per cent.
12.4j '3.19
12.46
IZ.SO
12.92
99.92 100.61 99.07
AgNOs found. cc.
0.5023 0.j327 0.5249 SOT
cc.
13.11
'rirE P R I ~ I A R Y PRODUCT.
The precipitate formed 11)- the action olf bromine water upon phenol is at first pure white in color, but on standing with the solution containing excess of bromine it gradually assumes a yellowish tint ; the change is due to the formation of trihromphenolbromide, the presence of which was detected by the qualitative tests described above. The change of color shows that tribromphenolbromide is not the primary product of the action of bromine water upon phenol. as imagined by IVeinreb and Eondi,? but is formed bv a gradual reaction I,et\vren the precipitated tribromphenol and the excess of bromine.
rE OF FORMATIOX. E! nieaiis q f the method of analysis described above, the amount of tril>roniphenoI~romideformed when the phenol was treated with bromine under varying conditions was determined. The following solutions were employed : Phenol, 20 grams per ~ c ~ 16.83 grams per liter ; the tribromphenslbroliter : s r l ~ /iitmtc. niide from j cc. of the phenol solution is thus equivalent to 10.74cc. of the silver nitrate Hypobrmqzitc, bromine was dissolved in a soluR.\
1
This is more than enough. excess does no h a r m
?
I?'fOnQfShe/f/ Chmire.
6,jo6 ( I F % )
S . J. LLOYD.
IO
tioii of caustic potash of known all
