Amination by Ammonolysis 111. Effect of Inorganic Salts P. H. GROGGINS AND A. J. STIRTON Bureau of Chemistry and Soils, U. S. Department of Agriculture, Washington, D. C. I n ammonolysis the principal reaction is accom- containing the halogen substituent attached to a panied by side reactions which are responsible for phenyl nucleus. The method described makes possible the manuthe formation of hydroxy derivatices, secondary amines, and reduction products. The introduction facture of 2-aminoanthraquinone at about one-half of ammonium salts to inhibit hydroxyl-ion concen- the cost entailed by the use of silver salt. I n view of tration gave results which at best were little better improvements in the yield and purity, and the than the control. The use of oxyhalogen compounds elimination of necessary puriJication operations, to oxidize the acid split off in the ammonolysis of there is a possible saving of about 25 per cent over halogenoanthraquinone proved to be eminently suc- the known method of preparation f r o m 2-chlorocessful. Binary mixtures of ammonium nitrate anthraquinone wherein no oxidant is employed. and potassium chlorate increased the range in which Furthermore, the process makes possible aminat ions good results could be obtained. Ternary mixtures which heretofore were impracticable on account of containing a copper compound in addition to potas- the impure character of the amine obtained. Under sium chlorale and ammonium nitrate also increased suitable conditions the amino compound is obtained the eflective temperature range for ammonolysis, directly in a high state of purity, and the removal of but it is questionable whether such mixtures are the ammoniacal mother liquor is the only treatment desirable except in the amination of compounds given to the Jinished product. N PARTS I and I1 (4) it was pointed out that the am-
I
monolysis of halogeno compounds is beset with two principal disturbing side reactions: (1) the formation of hydroxy derivatives through the activity of’ water or hydroxyl ions, and (2) the formation of second:iry amines by condensation in the presence of hydrochloric acid or arylammonium chloride. Solution of these two problems depends then on (1) depressing the hydroxyl-ion concentration of the ammoniacal solution, and ( 2 ) inhibiting the activity of hydrogen chloride or its ammonium salts.
DISCWSSION O F PROBLEMS The second problem has heretofore been given consideration by Hale and his associates (6). They state that the use of cuprous oxide is advantageous, since it reacts with and decomposes the ammonium halide that is formed during the reaction in accordance with the following equation: Cui0
+ 2SHaC1+
+ 2NH3 + € 1 2 0
C~iClz
It has previously been pointed out that copper oxides will go into solution in aqueous ammonia to form copper-ammonio hydroxides which are comparatively strong bases. It can furthermore be shown that other bases can serve to decompose the ammonium chloride formed during the amination process. Thus, for example, any oxide or hydroxide of the active metals may be used, but the increased alkalinity thus produced serves only to promote the adverse influence of hydroxyl-ion concentration. With increasing quantities of hydrogen chloride being liberated, the formation of secondary amines by condensation is promoted. This fact can better be appreciated by reference to the process for making secondary amines, such as diphenylamine, from primary amines by using hydrochloric acid as a catalyst. In this process Frei (1) states that the amount of acid employed may range between 1.5
and 5.0 per cent of the total quantity of primary amine taken. The condensation reaction is promoted by regularly releasing the ammonia split off. Thus, the removal of one of the products of reaction by lowering the ammonia concentration helps condensation. I n the treatment of chloroanthraquinone, the total hydrogen chloride split off during the course of amination would be roughly about 2.0 per cent of the total solution or 16.4 per cent based on the weight of primary amine formed. I n the ammonolysis of chlorobenzene, the quantity of hydrogen chloride formed obviously is 39.2 per cent of the aniline present. When consideration is given to the comparative concentrations of ammonium hydroxide and ammonium salts, it would not be surprising if the formation of secondary amines takes place readily during the final stages of the reaction. For this and other reasons it is often advantageous to disregard the practical philosophy of employing a low ammonia ratio when costly compounds such as 2-aminoanthraquinones are being prepared. Since it is necessary to obtain such compounds in a high state of purity, the technical advantage of using less ammonia is more apparent than real. EXPERIBZENTS WITH AhlMONIUhf SALTS
The effects of introducing ammonium salts were studied in order to determine whether the presence of a common ion would inhibit the formation of hydroxy derivatives in the ammonolysis of 2-chloroanthraquinone. The effect desired was not so much to obtain a generally high yield by inhibiting the formation of soluble hydroxy derivatives as it was to secure a product of sufficiently high purity to meet industrial requirements. Generally, 2-aminoanthraquinone of less than 97.5 per cent purity is not considered satisfactory for vat dye manufacture. The data recorded in Table I show the results obtained by incorporating ammonium salts in the autoclave charge. The
169
INDUSTRIAL AND
170
E N G I l E E R I S G CHEMISTRY
results show definitely that ammonium salts of reducing acids, such as ammonium oxalate and ammonium sulfite, are not suitable. The products from those charges showed signs of decomposition and the purities nere low. The results from ammonium nitrate and ammonium perchlorate were, however, only slightly better than the controls. Consequently, it m-as concluded that the employment of ammoniuni salts alone did not here contribute to the production of a sufficiently pure compound. TABLEI. EFFECTOF AMMOXIUM SALTSIT =\miouoi,ysIs OF 2-cHLOROASTHR-4QVI~OXE
2CHLOROtNTHH.4-
28%
EXPT Q U I N O N E N H B A r u o v r r v 311 i 1 L \ I P T n I E I r r ~ i ) 'P t I i r l > h G r a m s Grams Grilni, C !lour. Yo 70 08.4 91 1 .. 190 80 315 Control 1 36.375 9i.2 91.1 4 120 30 NHaCl 2 36.375 325 98 2 88.1 8 190 70 3 36.375 325 NHaCl 91.9 30 96.5 NHaClOa 1 190 4 36.375 325 8 8.0 30 9 7 . 6 9 ion 5 36.375 325 (NHI)&C), 83 5 30 95.5 (NHa)rC?On .5 190 6 36.375 325 6 6 .0 30 9 0 . 0 NHaNaBOa 7 190 7 36.375 325 ?4 95.: 315 Control 193 42.5 8 "4 96 I 19,j 315 8 NH4Rr 42.5 9 "4 9i 3 195 N H I C H ~ C O ~ 16 315 i n 42.5 95,s 91 . 0 18 315 Control 200 36.375 11 95.6 10 18 93.5 200 XHaNOa 35.375 315 12 94.5 24 9 5,9 6 200 NHpNO? 36.375 315 13 14 42.5 315 Control 200 20 94 6 91.6 15 42.5 315 NHiClOI i : 5 200 "0 97.0 91.8 16 41.5 315 "4x01 3.0 200 20 99.7 90.3 17 42.5 315 XHYOI 200 20 95.8 92.6 18 42.5 315 NHiNOa 8 200 24 96.5 89.6 a I n all tables, yield per cent = (weight of reactiun priiduct)/(neight of 2-aminoanthraquinone theoretically obtainable). b No purification steps were performed on a n y of t h e products obtained in this investigatlon.
{
EFFECTOF INTRODUCTI~S OF OXIDAKTS I t has been shown that the formation of secondary amines generally accompanies the preparation of primary amines ( I , 5 ) because of the presence of hydrogen chloride or its ammonium salts. In attacking the problem of inhibiting or ameliorating the deleterious activity of the acid, it was ascertained that the use of base-forming materials, such as metal oxides or alkali metal hydroxides, was unsatisfactory. These compounds, as can be seen from the experiments recorded in Table 11, do not give satisfactory results in the amination process, because hydrolysis as well as ammonolysis occurs. TABLE IN EXPT
11. EFFECTO F . & L K A L I S E - R E A C T I S G CO?JPOU;.jD* AMMONOLYSISO F 2-CHLOROANTHRAQrJISONEa~b COMPOUND USED Orams Control ... Control 6 NaOH 4.9 CaO 2.3 NaBOv4HnO 1.0 CUZO Cur0
...
6
190 195 190 190 195 200
E:: 1 195 .- 2-Chloroanthraquinone, 42.5 grains: 28%
7 a
{ C11
TEMP. TIME YIELD C. Hours 7, ._ 30 24 30
30 24 24 24
aqueous
98.4 95.6 70.6 93.4 94.8 92.7 96.1 "1,
PURITI
% 9111
90.0 52.5 R5.6 91.1 88.2 88.5 315 grams;
capacity of autoclave, 500 00. b Charge, 36 375 grams.
Oxidation was found to be the most satisfactory method of counteracting the influence of hydrochloric acid or its ammonium salts in the reaction mass. The use of oxyhalogen compounds leads to consistently improved results. In this class of compounds may be included the salts of hypochlorous acid (HOCl), perchloric acid (HClOJ, and chloric acid (HC103).' The bromates and iodates are likewise beneficial but not to the same extent.
POTASSIUM CHLORATE AS OXIDAKT In Table I11 are presented the data relating to the use of potassium chlorate in the ammonolysis of 2-chloroanthra1
Covered by separate government a n d industrial applications for p a t e n t
Voi. 2 5 , KO. 2
quinone. These show that a product of 97.6 to 97.8 per cent purity can be obtained, with a yield of over 96 per cent of the theoretical. When consideration is given to the facts that (1) technical 2-chloroanthraquinone was used; (2) a comparatively low ammonia ratio-i. e., 7.4 :1 by weightwas provided; and (3) ordinary 28 per cent aqueous ammonia was used, the procedure appears to provide a satisfactory basis for economical technical operations. Attempts to obtain satisfactory results by increasing the quantity of chlorate and decreasing the reaction temperature were unsuccessful. It is also evident from the data that the conditions which proved eminently satisfactory for larger sized charges were not the optimum for smaller batches. It is apparent that the best results are obtainable only over a narrow range, and the translation of such experiments to technical operations might be fraught with difficulties, even with precise regulation of operations. Later it will be shown that the inclusion of a second and milder oxidant along with the chlorate makes it possible to secure satisfactory results over a wider range of conditions. T A B L E 111. EFFECT O F P O T A S S I t 3 f C I f L O R A T E AS 0x1D A N T I S PREP.4RATION O F 2 - A ~ I N 0 . ~ r T H R A Q U I S o ' E a 2-CALOROANTHRA-
EXPT.QEINONE Grams 1 '2
3 4
5
Q '3 10 11
36.375 36.375 36,375 86 3 i 5 36.475 36.375 !6.37,5 36.375 42.5 42.5
42.5 42.5 1 2 ,d 42.5 42,5 42,5 4.0 41,5 18 42.5 4.0 3 .0 19 42.5 20 42.5 L25 C a l a r i t y uf n u t w l a v e ,
1:!
1:i 14 1.5 16 1;
Tmip. TIME YIELD PURITY NET YIELD C. EIourv % % % 91.4 86.4 195 24 94.5 93.5 90.2 195 24 96.5 92.1 34 96.5 95.5 195 91.2 24 95.7 95.4 195 90.2 21 95.5 91.5 195 91.0 24 97.2 93.7 190 95.1 9 2 . 0 190 24 96.t 90.9 24 98.6 92.2 188 90.9 86.8 24 95.6 195 89.5 93.5 24 95.7 193 93.6 24 97.9 195 95.6 86.7 91.6 200 20 94.6 94.0 97.8 20 96.1 200 20 96.8 97.6 9 4 . 5 200 92.7 195 24 96.3 96.3 91.8 95.2 96.4 24 195 91.9 24 9 5 . 3 9 6 . 4 195 9 3 . 0 89.0 2 1 9 5 . 7 192 89.5 21 97.7 91.6 192 89.6 8 7.5 20 9 7 . 4 190 500 cc.; 2870 aqueous "a, 315 grams.
KClOa Gram. Contrul 0.8 1.0 1.25 1 50 1.0 1.2 8.0 Ciintrol 0,i.j 1 "5 colltrGIIOFF, S t a t e T-ni\ersitj of I m a , Iowa C i t j , Iowa
The nmoiznt qf corzcerzfrate Iiuiiiig a specific pounds (1.8 to 10 kg.). There grarity of 1. 2 arid [he amount qf avh lL?}iichcurl be no geographical relation to the disposal of Bteffen's waste, obfairzedj r o ma gipe,Lanlounf of dilute LL3astes amount obtained. The high& a d e t e r n i i n a t i o n of the mineral content of wastes obJ i e l d is 22 p o u n d s from St. vary with the geographical sorir,e of the wade. tained froni various parts of the I,ouis, h I i c h , ; coIrles country has been first underThe at'erage Potassium corderd Of the ash f r O i i l 11asoii City, Iowa, with 12 and [he thirteen sanzples of irasfes inaestigczted is 1 6 pound., respectirely. Tlie taken. Thirteen samples of the dilute waste were obtained from 34.64 Der c-ent. The Dotassiunz a71d sodium lowest yield n-as 4 pound.: from factories scattered through the content; do rary, fhe sulfate and chloride Co1o. area from Alichigan to Utah as contents do i w y with the geographicwl source of . follows: Colorado-Sv-ink. Fort DETERNISATIOSS OF RESIDUE:. the Luaste. Collins, Loveland, Delta; AIichiT-OLATILE AIATTER, ASD AYH gaii--St. Louis, Blissfield; KeFork, Lewiston : braska-Grand Island; Utah-Spanish There mas no correlation between volatile matter or TTyoming-Torrington, Rorland ; Iowa-AI ason CXty(pond), residue on ignition and the amount of concentrated material hIason City (campaign), obtained. The neight of the concentrated material ohThrough the courtesy of the various companies, barrel tained depends on the dissolyed subqtance in the waste, 'which samples were obtained. A11 of the samples were treated is affected by seasonal variation in the composition of the with carbon dioxide to remove the calcium before concentra- beet and the mineral content of the 11-aterused in the process tion. Throughout the work care was taken to heat the (8)' samples uniformly so that fair comparison of the results The waste before carbonation has yarying amounts of roiild be macle. excess lime which has been added in the precipitation of the wgar. I n this work, therefore, all analyses have been made COVCE\TR~TIOS OF WASTE of the dilute wastes after carbona t'ion. Fifty cubic centimeters of each waste were evaporated in The concentration vas carried out in a vacuum evaporator. Determinations were made of the weight and specific gravity platinum dishes, dried a t 100' C., and weighed. Any higher of the dilute naste, the specific gravity after treating with temperature caused decomposition of nitrogenous comrarbon dioxide gas (to a faint color with phenolphthalein), pounds. The residue was ignited by charring over a n open and the weight and specific gravity after coricentration flame, and then heated in an electric muffle a t a dull red heat. The ash was weighed and saved for analysis. The results (Table I). Of the analysis are shown in Tahle TI. T \ R L E I. SPECIFIC C:RiVITIEb AYD ITEIGHTb O F \I74>TE BEFORE T L R L E 11. RL\IDUE- i \ U T-OL-ITILh 1\14TlEN ~ Y DAFTER CONCEYTR ~TIOV S I: general qtudy of the
14
&
r PL \CE
-
Dilute
S G ~R ~ITYX ~ ~ .After ConcenCOn t r a t e d
1.014 i . n i ~ 1~,013 1 . 0 2 0 1.014 1 . 0 1 3 1.010 1 022 1 . 0 1 5 1 011 1 , 0 0 8 1.01.5 1,009 1.01.2 1 , 0 0 9 1 014 1.010 l.Oll3
1,0113 1 012 1 01:' 1 018
1.420 1.410 1.396 1.406 1.408 1.440 1.392 1,404 1.414 1,012 1.460 1.007 1,454 1.016 1 . 3 9 2 1.014 1.415
~ ~ ~ ~ WEICIIT Dilute Concentrated
433 (196.4) 422 (191.4) 1 2 0 (190.5) 42 1 (191) 427 (193.7) 413 . 5 (187.8i 420 ( 1 9 0 . 5 ) 410 (190.5) 444 ( 2 0 1 . 4 ) 426 ( 1 9 3 . 2 ) 400 (181.41 417 ( 1 8 9 . 2 , 423 ( 1 9 1 . 9 )
PI.
\Ch
Su-ink, Colo. Delta, Colo. I.o~-eland,C o l n . F t . Ciillinn, C o l < ~ . 8t.Louis, I I i c h . Blissfield, M i c h . Grand Island, Nebr. Lewiston, U t a h Spanish F o r k , Utah Torrington, W y o Worland, Wyo. l l a s o n City, loa-a 'p) Mason C i t y , IoIva : C I 1 7 erage
8,s
4.0 7.5 8 5 22.0 6 5 9.0 8.5
13 0 7.0 5.0 16 0 12.5
The specific gravity is reduced by carbonation
