Aug., 1943
ACYLATION OF 3-PHENYL-5-PYRAZOLONE AND 3-ANILINO-5-PYRAZOLONE
Summary The effect of ascorbic acid and dihydroxymaleic acid on the autoxidation of various organic developing agents is investigated. I n two experiments, stannous ion and hydrazine are added to hydroquinone solutions. A retardation is observed in most cases. This is explained on the assumption that the autoxidation of the developing agents is catalyzed by their quinonoid oxidation products, and that the added reducing agents eliminate these quinonoid products. The quinones are assumed to catalyze the autoxidations by virtue of their reaction with the
[COMMUNICATION N O .
930 FROM
THE
1495
developing agents in which highly reactive semiquinones are formed. Most likely the latter are also reduced by the inhibitors. In some cases, the reducing agents accelerate the autoxidation of the developing agents. The acceleration is caused by the formation of semiquinones in the reduction of the quinones. This interpretation is supported by . experiments in which #-cumoquinone accelerates the autoxidation of ascorbic acid to an extent which cannot be explained by a reduction of the $-cumoquinone to the #-cumohydroquinone and autoxidation of the latter. ROCHESTER, NEWYORK
RECEIVED APRIL1 2 , 1943
EASTMAN KODAK LABORATORIEf,]
Investigation of Pyrazole Compounds. IV.’ The Acylation of 3-Phenyl-5-pyrazolone and 3-Anilino-5-pyrazolone BY A. WEISSBERGER AND H. D. PORTER The acyl derivatives of l-phenyl-3-amino-5- silver halide of the emulsion and the compound pyrazolone were described in the first paper of this under test, if it is of suitable constitution, couples series2 where the constitution of the parent com- with the oxidized developing agent t o form a dye pound was established. The present paper deals with a )C=N-N(CHah group? The with the acylation of 3-phenyl-5-pyra~olone,~ film is washed, silver and excess silver halide are and 3-anilin0-5-pyrazolone.~~~ The determinaremoved with a photographic reducer and thiotion of the positions of the acyl groups was again sulfate, and a clear film is obtained. If a dye is assisted by color tests, in which the substance formed, it gives information by its existence, colore under investigation is heated with p-nitrosodiand location, on the nature of the parent commethylaniline,’ or oxidized in the presence of ppound. The dye may be deposited throughout amin~dimethylaniline.~ the emulsion layer of the film, a t the emulsion A modification of the latter test, which uses the surface only, or it may be found in the developer silver halide of a photographic film as the oxidizsolution. If the molecular weight of the dye is ing agent, was most helpful. Originated by low and the solubility in the alkaline developer Fischer and Siegrist,e i t has become the basis for high, the dye formed in the emulsion layer may several successful color photographic processe~,~ bleed entirely or in part into the developing and is frequently used in color photographic resolution. On the other hand, coupling comsearch. The compound is dissolved in carbonate, pounds which, because of their low rate of an unsymmetrically dialkylated developing agent diffusion, do not penetrate into the gelatin, react of the p-phenylenediamine class, e. g., p-aminodionly with that oxidized developing agent which methylaniline, is added, and a strip of exposed diffuses out of the emulsion. These compounds photographic film is immersed in the solution. form dyes on the surface of the film or as a preThe p-phenylenediamine derivative reduces the cipitate in the liquid. I n carrying out the film(1) Investigation of Pyrazole Compounds, 111, THISJOURNAL, 66, strip test, a blank should be made to distinguish 732 (1943). (2) Weissberger and Porter, ibid., 64, 2133 (1942). the dye formed as described above from colored (3) Curtius, J . prakt. Chcm., 60, 515 (1894). oxidation and condensation products formed by (4) Worrall, THISJOURNAL, 44, 1551 (1922). (5) Weissherger and Porter, ibid., 66, 62 (1943). the developing agent in the absence of couplers. (6) Fischer and Siegrist, Phot. Korr., 61, 19 (1914). (7) Davies, Phot. J., ?6, 248 (1938); Forrest and Wing, J. SOC. M o t . Ptct. Eng., 49, 248 (1937); Mew. J. Prankl. Ins;., 988,50 (1942).
(8) Mees, “The Theory of the Photographic Process,” The Macmillan Co., New York, N Y . , 1942, p 393.
Vol. 65
A. WEISSBERGER AND H. D. PORTER
1 491i
3-Phenyl-5-pyrazolone, I, on heating on the tives, VI is more readily hydrolyzed by alkali than IT. steam-bath with acetic anhydride forms, accord CsH, -C ---CH ing to the litera turc,3'9 I-acetyl-3-phenyl-5-pyra1 Il zolone, 11, melting a t 121 We found that IT N C--OAc +J/' C,4"---C -----CH2 CbHs---C - -- CFJ
/I
N
C#l
LI. VI
1
I1
' h
00
When I1 is heated in pyridine, i t rearranges completely to form VI. I n this reaction, an TI acetyl group wanders from nitrogen to oxygen, iiielts a t 137--138-, and that the lower m. p. re- a migration which has been observed in a few ported in the literature is caused by the presence cases12only The rearrangement explains why VI ot up to 20e/;. of another monoacetyl compound rather than I1 is formed when I is acetylated in melting a t 150". Structure I1 is confirmed for pyridine. The reverse rearrangement, of VI tCJ the compound melting a t 1X3. This is soluble 11, was not observed in pyridine. However, on 111 carbonate, excluding 0-acetylation, and is heating in acetic acid, not only VI is formed from hydrolyzed to 1 bv caustic alkali. Inasmuch as 11, but the reverse migration also takes place. ' -phenvl-3 tnt.thyl--l-acetyl-5-pyrazolone. 111, i s Since the acetyl group is present in the solvent, the reaction in acetic acid is probably not a migrac H1-- e--- CIlAc tion in the strict sense but rather an exchange re\ icy cictioii with the solvent which proceeds with S isomerization. C& Acetylation of I1 or of V I gives the diacetyl III derivative of m. p. 84' which was obtained by von stable to caustic alkali,1° the hydrolysis ex- Rothenburg on acetylation of I and was formucludes C-acetylation in position 4. With these lated as 1,2-dia~etyl-3-phenyl-5-pyrazolone,~ VI1 properties, the compound melting a t 127' might In view of the formation from I1 and VI, the still be l-acetyl-3-hydroxy-5-phenyl-pyrazole, IV, diacetyl compound is more likely to be l-acetylthe carbonate solubility being analogous to that .i-phenyl-5-dcetoxypyrazolone, VIII. This strucof 1 - phenyl - 3 - hydroxy - 3 - methyl - pyrazole, C&3&--C=CH CJ-I,-C-CH V." However, the compound melting a t 12;' I 1 I/ It Ac-N CO N C-OAC CsHj--C==CH CH3-C=--;CH .E' \N/ ' I 1 1 Ac
I
Ac-N
C- OH
CcH;---N
'\ X
N
IS'
C
>
readily forms a magenta dye, not only with p aminodimethylaniline in the film-strip test, but also with p-nitrosodimethylaniline. With a compound of structure IV, the dye formation would involve a deacetylation, and this is unlikely to occur in the condensation with p-nitrosodimethylaniline. The monoacetyl compound melting a t 150" is best prepared by acetylation of I in pyridine. It is insoluble in carbonate and readily hydrolyzes to I with caustic alkali. I t . is. therefore, 3phenyl-5-acetoxypyrazole, VI. In agreement with this structure and with the general behavior oi 0-acetyl as compared with E-acetyl deriva(9) von Rothenburg, J Orakt. Cllem i10) Stoltk rbrd 65, 142 (1897) f I \ T a % ? r B o 96 7 ! i (1003,
52, 31 (18951
I
(JH
'X'
.IC
1 TI
Ac VITI
ture is confirmed by the deacetylation of von Kothenburg's compound to I1 and to VI, with alcoholic piperidine and with water-containing acetic acid, respectively. Formula VI1 could only be maintained if during the acetylation and the deacetylation there occurred reversible migrations of acetyl, consistent with the yields obtained. 'This is not the case, particularly in view of the fact that no rearrangement of VI was found in pyridine. Besides VIII, a new diacetyl derivative melting a t 7.5" can be isolated in small yield when I 1s boiled with acetic anhydride. By the same treatment, VI11 itself is rearranged to the new conipound. Like 17111, this is insoluble in carbonate. (12) C 1%' Porter, 'Molecular Rearrangements CItalor Complnr 1 ili , l e w York N Y 1928
"
T h e Chemical
Aug., 1943
ACYLATION OF 3-PHENYL-5-PYRAZOLONE AND 3-ANILINO-5-PYRAZOLONE
1497
Acetylation on carbon is excluded by the hydrolyThe benzoylation of I, with one mole of benzoyl sis to I, leaving as possible formulas, VI1 and chloride in pyridine, gives a monobenzoyl derivathat of a 1-acetyl-3-acetoxy-5-phenylpyrazole,tive, which is insoluble in aqueous alkali and IX. On heating with piperidine, the new diacetyl regenerates the parent compound with alcoholic piperidine. It is, therefore, 3-phenyl-5-benzoylCeHs--C=.CH I I oxypyrazole, X. When this is acetylated, the A-N C-OAc product formed can be debenzoylated with piper\N/ idine to 11, and is therefore l-acetyl-3-phenyl-5IX benzoyloxypyrazole, XI. compound yields a new monoacetyl derivative melting a t 144'. The latter is soluble in carbonCeHb-C-CH %HE-C-C-H I1 11 II II ate, hydrolyzed to I in alkali, and forms a dye N C-OBz N C-OB2 neither with p-nitrosodimethylaniline nor in the \N/ \N/ film-strip test. Thus, it has the properties H I Ac which, as discussed above, are to be expected of X XI IV; this structure is therefore assigned to the In order to benzoylate X further, it was treated monoacetyl derivative melting a t 144'. No with benzoyl chloride in pyridine or in toluene, migration of acetyl from nitrogen to oxygensimilar to the change of I1 to VI-was observed In both cases, a dibenzoyl derivative of m. p. with IV in pyridine. However, from a solution 117' was obtained. When toluene was used, this of IV in acetic acid, VI could be isolated after was accompanied by a dibenzoyl derivative of heating. It is probably formed by an exchange m. p. 181'. Both compounds are insoluble in reaction with the solvent. The formation of aqueous alkali, but regenerate I with alcoholic I V by partial deacetylation of the compound sodium hydroxide. Since l-phenyl-3-methyl-4melting a t 75' agrees as well with formula VII benzoyl-5-benzoyloxyyrazole, XII, on treatment with caustic alkali loses only that benzoyl as with formula IX. With water-containing acetic acid, i. e., the group which is attached to oxygen, l4 the regeneraconditions under which VI11 is deacetylated to VI, tion of I excludes attachment of a benzoyl group the diacetyl derivative melting a t 75' also yields to carbon. Attempts to obtain information on VI. Provided that no migration of acetyl occurs the structure of the dibenzoyl derivatives by parin this deacetylation, the diacetyl compound is tial debenzoylation with piperidine failed. With IX. Then, in the formation of I X from VIII, an the lower melting compound, only I was isolated acetyl group would wander from nitrogen 1 to besides the starting material. The pure materials nitrogen 2. This type of migration was studied recovered accounted for only a small part of the by von Auwers and Dietrich,13and, in agreement reactant. The higher-melting compound, after with the results of these authors, the acetyl group the same treatment, was recovered almost would wander to that nitrogen atom which, in quantitatively. view of the groups attached to it, is the more basic CH~-C---C-BZ CeHb-C=CH one. With structure VI1 for the diacetyl derivaN ll C-OB2 II Bz-T!4' LO tive melting a t 75', the formation of this com\N/ "/ pound from VI11 would involve the migration of I I Bz GHs acetyl from oxygen to nitrogen in position 2, and XI1 XI11 the deacetylation to VI would imply the reveise With hydrogen chloride in dioxane, both commigration. Although the possibility of the latter migration is demonstrated by the formation of VI pounds are debenzoylated to X, and therefore from IV, one is inclined to prefer formula I X over neither is likely to be l12-dibenzoyl-3-phenyl-5VI1 on account of the less complex relation to pyrazolone, XIII, a structure which would be VI. This preference is enhanced by evidence to analogous to von Rothenburg's formula for his be presented in discussing the acetylation of 3- diacetyl compound. Formula XI11 would be anilino-5-pyrazolone. We therefore assume for possible only if, with hydrogen chloride in dioxthe diacetyl compound melting a t 75" formula ane, a benzoyl group wandered from nitrogen IX, although VI1 cannot be dismissed entirely. to oxygen and the reverse migration occurred in (13) von Auwers and Dietrich, J . prakt. Chcm., 139, 65 (1934).
(14) Michaelis and Engelhardt, Bw., 41, 2668 (1908).
-A. WEISSBERGER AND H. D. PORTER
149s
Vol. t i t i
ChHjNH--C-=CH CcHJXH-C-CH the benzoylation of X. By the process of elimination, therefore, one of' the dibenzoyl deriva '11. N C--OH CnH )-K C -4 ) f 1 tives must be 1 -benz:,yi-3-phenyl-~-benzo~l(~x~7" pyrazolone, XIV, and the other 1-benzoyl-:.PORTER
IIi7was also obtained, in 67 and 25% yield, respectively, by adding one equivalent of piperidine to a boiling absolute
Vol. 65
0.8 g. of acetyl chloride was added to a cold solution of 1 g. of VI, in 5 ml. of pyridine; the mixture was stirred a t room
ethanol (4 ml./g.) solution of l-acetyl-3-phenyl-5-acetoxy- temperature for twenty-four hours, decomposed in icepyrazole, VIII, or of l-acetyl-3-phenyl-5-benzoyloxy- water and the residue recrystallized from methanol. pyrazole, XI, refluxing for fifteen minutes and cooling. On stirring a t room temperature with 2% sodium hyOn standing in 2% sodium hydroxide solution at room droxide, VI11 dissolved within one-half hour. The solutemperature for one hour. 11 was hydrolyzed to 3-phenyl-5- tion gave on acidification 3-phenyl-5-pyrazolone, 1 . 1 7 pyrazolone, 1.l' l-Acetyl-3-acetoxy-5-phenyl-5-pyrazole,1X.-( 1) A so1-Acetyl-3-hydroxy-5-phenylpyrazole,IV, was prepared lution of 25 g. of 3-phenyl-5-pyrazolone, I,a in 50 ml. of IX, (0.75 g,) acetic anhydride was refluxed for six hours, cooled and 20 g. from l-acetyl-3-acetoxy-5-phenylpyrazole, following the procedure for the preparation of I1 from VIII. of ice added. The crystalline mass formed on scratching 'The crude product (7.5%) was twice recrystallized slowly was filtered, rinsed with 20 ml. of 50% ethanol, and recrysironi benzene, 0.15 g. (25Y0i of fine white needles: in. p. tallized from methanol, warming only to 45" and letting i 44-146". cool to room temperature undisturbed, to give 11.5 g. .4m!. Calcd. for C,IHION&: N,l.%% Fouud: N, (31.5%) of VIII.17 The filtrate, on cooling, gave 12 g. of mixed crystals (m. p. 55-62') which were recrystallized 13.7;. 1V was unchanged by heating for half an hour in pyridine from 120 ml. of "heptane" (Eastman Kodak Co.), cooling slowly in a hot cupboard a t 40' to give IX. With small on the steam-bath. 3-Phenyl-5-acetoxypyazole, VI.-To a suspension of additional amounts obtained by the same procedure from the various filtrates, the total yield was 5.3 g. (14.5%) of 4 g. of 3-phenyl-5-pyrazolone, I,3 in 10 ml.of pyridine on long, colorless prisms; rn. p. 75-76'. Rapid recrystallizathe steam-bath was added 2.5 g. of acetic anhydride, dropwise with stirring. The solution was heated fifteen min- tion from "heptane" gave white needles; m. p. 75-76". utes longer, cooled, and diluted with water (10 ml.) uiitil -.lmi/, Calcd. for C:aH1&203: N, 11.48. Found: N, just cloudy. Crystallization was induced by scratching, 11 :i2 the mixture cooled, and filtered to yield 2.2 g. (44%) of ( 2 1 A solution of 7 g. of l-acetyl-3-phenyl-5-acetoxywhite granules; m. p. l50--1 , unchanged after recrys- pvrazole, P H I , in a mixture of 9.6 ml. of acetic anhydride tallization from methanol. arid 0.4 ml. of acetic acid was refluxed for three hours. d.Calctl. for C&IlnN.O>: Ti',13.85. I;(>uliil: X, U'orked up as in procedure (l), 2.1 g. (307,) of unchanged \'III1i and 0.9 g. (13%) of I X resulted." WThcn 2 g. of acetyl chloride was used in place of the 'Kheri I X was shaken with 2% sodium hydroxide in 30% acetic anhydride and thereaction run a t room temperature, ethanol for ten minutes, the solution, after filtering from SI:' (40%) was also obtained. the undissolved material, gave on acidification and concenOn shaking with 270 sodium hydroxide, VI dissolved in tration 3-phenyl-5-pyrazolone, I.l7 about ten minutes t.o give, on acidification, 3-pheiiyl-33-Phenyl-5-benzoyloxypyrazole,X.-To a solution of pyrdZOloIle, 1." 10 g. of 3-phenyl-5-pyrazolone, I , 3 in 50 ml. of pyridine VI'? was formed by partial hydrolysis of l-acetyl--:i- heated on the steam-bath was added 8.9 g. of benzoyl phenyl-5-acetosypyrazole, VIII, and of 1-acetyl-3-acetoxy- chloride, dropwise with stirring. After five minutes the 5-phenylpyrazole, I X . When the solutions of these coni - solution was cooled to room temperature and diluted with pounds in 66% acetic acid (6 ml./g,) were refluxed for ten water (30 ml.) until just cloudy. Crystallization was illminutes, VI crystallized after cooling in 257, yield. I t was duced by scratching, the mixture cooled under the tap, fornied by a rearrangement of 1-acetyl-3-phenyl-5-pyrazo- filtered, and rinsed with 95% ethanol, 11 g. (670/,), m. p. ione, .[I, subjected to the conditions just stated. From the 1ci9--I7l3; recrystallized from 95% ethanol, feathery, reaction separated crystals (30% of the weight of IIj white crystals; m. p. 170-171'. which consisted of about equal parts oi VI1r and of 3. I I I ( L I . Calcd. for CIJ11.2NIL'102: N, 10.6. Found: N. phenyl-5-pyrazolone, 1,;''the former being extracted with 11J. I:. benzene. When VI'? itself was subjected to these condiXIr (16%) was also obtained when dry hydrogen chloride tions, 25% of it was recovered. Vl17 was also formed (isolated in 10% yield) by a rearrangement of I1 aiid of 1- was bubbled for three hours through a hot dioxane solution XIV, or of 1 acetyl-3-hydroxy-5-phenylpyrazole, IV, on heating in of l-benzoyl-3-phenyl-5-benzoyloxypyrazole, XV. The solugiacial acetic acid (3 ml./g.) for half an hour. When 1-1 benzoyl-3-benzoyloxy-5-phenylpyrazole, itself wa.j subjected T O this treatnienr. II'? was i,solated in tioiis, after cooling, were filtered, and the product triturated with 95% ethauol. yield. X was debenzoylated to Ii7under the conditions for thv By a rearrangement, V I I 7 was also obtained on heating I1 in pyridine on the steam-bath for half an hour. However, formation of I1 from XI. l-Acetyl-3-phenyl-5-benzoyloxypyrazole, =.-A mix no change in the r n . p of VI" was effected by the samr rurr of L g. of :~-phenyl-5-benzoyloxypyrazole, X, and 4 treatment. .l-Acetyl-3-phenyl-5-acetoxypyrazole, VIII, was pre- nil. of acetic anhydride was heated on the steam-bath for pared, by heating with excess acetic anhydride (2 ml./g.) on one himr, cooled and filtered, 0.7 g. (57%). m. p. 108-109'; thie steam-bath for half an hour, from 3-phenyl-5-pyrazo- recrystallized from methanol, firie white needles; m. p. 108lone, 1 3 (yield 6070),9from l-acetyl-3-plienyl-5-pyrazolone.1O!! .-lnui. Calcd. for C18HllN203: C, 70.5; H, 4.57. I I, (yield 50%) and from 3-phenyl-5-acetoxypyrazole, V I 'vicld INK$%\. 1JIIIt" was further obtained 1~G7~> when
Aug., 1943
ACYLATION OF 3-PIBNYL-5-PYRAZOLONE AND
3-ANILINO-&PYRAZOLONE
1501
XI" was also obtained (50%) by acetylation of X with preparation of I1 from VIII, or (15%) by boiling in glacial acetic acid for two hours. acetyl chloride in pyridine solution. l-Benzoyl-3-phenyl-5-benzoyloxypyrazole, XIV.-To a With 2% sodium hydroxide (see 11),XXa was hydrolyzed solution of 2.6 g. of 3-phenyl-5-benzoyloxypyrazole, X, in to 3-anilino-5-pyrazolone, XV1.I' It was unaffected by 5 ml. of pyridine heated on the steam-bath, was added 2.1 boiling in glacial acetic acid for two hours. g. of benzoyl chloride, dropwise with stirring. Heating l-Acetyl-3-anilino-5-aceto~yrazole, XXIa, was prewas continued for half an hour, the mixture cooled, decom- pared like XXa, but the reaction mixture was heated for posed with ice-water, filtered, and the product recrystal- half an hour. A fist crop separated on cooling of the lized from 65 ml. of 95% ethanol, 2.1 g (58%) of short, reaction mixture. The a t r a t e from this was decomposed white needles; m. p. 117-118'. with ice water, filtered and the solid material washed with Anal. Calcd. for CzsH16NzOs: N, 7.6. Found: N, boiling ligroin to leave a second crop, recrystallized from 95% ethanol, 65% of short, white needles; m. p. 131-132'. 7.58. Anal. Calcd. for C1,HlaNaOa: N, 16.2. Found: N, When XIV was shaken with 2% sodium hydroxide in 50% ethanol for one hour, the solution, after filtering from 16.05. From XXa under the above conditions XXIal' was obthe undissolved material, deposited on acidiiication and concentration 3-phenyl-5-pyrazolone, L17 After deben- tained in a 70% yield. l-Acetyl-3-acetoxy-5-anilinopyrazole,XXII, was prezoylation with piperidine under the conditions for the formation of I1 from XI, only a small amount of 3-phenyl- pared according to the procedure given for the preparation of XXIa, but the reaction mixture was refluxed for two 5-pyrazolone, 1,17and a small amount of unchanged XIV" hours. It was then cooled, decomposed with ice water, were obtained in pure form. l-Benzoyl-3-benzoyloxy-5-phenylpyrazole, XV.-To a and the product recrystallized from ligroin, 35% of white, solution of 2.6 g. of 3-phenyl-5-benzoyloxypyrazole, X, in granular crystals; m. p. 108-109°. Anal. Calcd. for C I ~ H I ~ N ~N,O ~16.2. : Found: N, 25 ml. of boiling toluene was added 1.4 g. of benzoyl chloride, the mixture refluxed for three hours, cooled, filtered 16.26. and the product recrystallized from absolute ethanol, 0.8 g. XXII was also obtained (6%) by concentration of the ligroin washings from the preparation of XXIa, and (22%) of short white needles; m. p. 181-182". Anal. Calcd. for C Z ~ H I ~ N ~ O C,, :74.9; H, 4.35; N, (10%) by refluxing XXIa in glacial acetic acid for two hours. Only unchanged XXIa was recovered after re7.6. Found: C, 74.84; H, 4.20; N,7.41. The a t r a t e of the reaction mixture on diluting with four fluxing in dry xylene for two hours. Under the conditions volumes of petroleum ether gave 2 g. (54%) of crude 1- of the hydrolysis of IX, XXII was hydrolyzed to 3-anilino5-pyrazolone, XVI.17 benzoyl-3-phenyl-5-benzoyloxypyrazole, X1V.l' 3-Anilino-5-benzoyloxypyrazole,XXII1.-( 1) To a susWith 2% sodium hydroxide (see XIV), XV was hydrolyzed overnight t o 3-phenyl-5-pyrazolone, I.17 Attempted pension of 5 g. of 3-anilino-5-pyrazolone, XVI,ls4 in 50 ml. debenzoylation with piperidine under the conditions for the of pyridine and 0.5 ml. of water was added dropwise with formation of I1 from XI gave a n almost quantitative re- stirring 8 g. of benzoyl chloride, a t a temperature just below covery of XV.I7 After heating the reaction mixture over- 45". After standing at room temperature for half an hour, night, 15y0 of XV17 was recovered, but no other pure 100 ml. of water was added, the precipitated oil brought to crystallization, filtered, and digested with 30 ml. of benproduct could be obtained. l-Acetyl-3-hydroxy-5-aniliiopyrazole, XVII, was pre- zene, 6 g. (75%); m. p. 146-148". Recrystallized from pared from l-acetyl-3-acetoxy-5-anilinopyrazole, XXII, 95% ethanol, white flakes; m. p. 148-150". The melt (0.3 g.) following the procedure for the preparation of partially re-set above the m. p. Anal. Calcd. for ClsHlaN3Oz: N, 15.0. Found: N, I1 from VIII. Recrystallized from absolute ethanol, 0.1 g. 15.09. (40%); fine white granules; m. p. 203-205" dec. XXIIIl' was also obtained (25%) by heating XVI with Anal. Calcd. for C11H11NPO1: N, 19.3. Found: N, one equivalent of benzoic anhydride in pyridine solution, 18.99. besides 28% of l-benzoyl-3-anilino-5-benzoyloxypyrazole, With 2% sodium hydroxide (see 11), XVII was hydroXXV," from which it was separated by extraction with lyzed to 3-anilino-5-pyrazolone, XVI.17 benzene. l-Acetyl-3-anilino-5-pyrazolone,XXa.-A mixture of 1 Under the conditions for the formation of I1 from XI, or g. of 3-anilino-5-pyrazolone, XVI,1*4and 10 ml. of acetic for the hydrolysis of XIV to I, XXIII was debenzoylated anhydride was stirred and heated on the steam-bath for to 3-anilino-5-pyrazolone, XVI.17 six minutes, cooled, atered, and the product recrystallized l-Benzoyl-3-anilino-5-pyrazolone,XXTY. -A mixture of from acetic acid, 0.8 g. (65y0) of white crystalline powder; 7.8 g. of 3-anilino-5-pyrazolone, XVI, 60 ml. of pyridine, m. p. 207-209" dec. and 12.4 g. of benzoyl chloride was heated on the steamAnal. Calcd. for CllHllNaOz: N, 19.3. Found: N, bath for fifteen minutes, then 0.8 ml. of water was added, 19.14. and heating continued for fifteen minutes. The solution, No 0-acetyl product could be isolated when XVI was cooled to room temperature, was diluted with water (40 subjected to the conditions for the preparation of VI from ml.) until just cloudy, cooled under the tap and filtered, I, using, for solubility reasons, three times the amount of 7.6 g. (65%) of yellowish needles; m. p. 193-196" dec. pyridine. Instead, m a 1 7 (50%) was obtained. Recrystallized from 70 ml. of acetic acid, 3 g. of fine ivory m a l 7was also obtained (81%) from 1-acetyl-3-anilino- needles; m. p. 198-200" dec.; loss probably caused by &acetoxypyrazole, XXIa, following the procedure for the debenzoylation.
L'iO?
C. 1;. H. ALLENAND J. W r . GATES,JR.
ir01. 65
.irzal. Calcd. for CisHlaN&: Tu', 15.0. Found: N, i-k.85. XXIV was comparatively stable to 2% sodium hydroxide. Under the conditions described for the hydrolysis of XXa, the m. p. %'as only lowered to 190-195" dec.
.~-Phenyl-5-acetoxypyrazole,VI, 1-acetyl-3-acetoxp-3-phenylpyrazole, IX, 1-acetyl-3-hydraxy3-phenylpyrazole, IV, 3-phenyl-5-benzoyloxypyrazole, X, l-acetyl-3-phenyl-3-benzoyloxypprazole, XI, I-benzoyl-3-phenyl-5-benzoyloxypyl-Benzoyl-3-anilino-5-benzoy~oxypyrazole, XXV.--A mixture of 5 g. of 3-anilino-5-pyrazolone, XVI,1*4 and 4 g. razole, XIV, 1-benzoyl-~3-benzoyloxy-3-phenylof be~izoylchloride in 50 ml. of dioxane was stirred on the pyrazole, XV, 1-acetyl-3-hydroxy-5-anilinopysteam-bath overnight. After cooling, the solution was razole, XVII, l-acetyl-3-anilino-5-pyrazolone, tieranted from a n oil, diluted with water ( 5 ml.) until XXa, l-acetyl-3-anilino-5-acetoxypyrazole, XXIa, cloudy, cooled, filtered, and the product recrystallized from l-acetyl-3-acetoxy-3-anilinopyrazole, XXII, .iiT, tnl. of dioxane. I g. (13y07,) of short ivory needles; ni. p. ::32--134 anilino-3-benzoyloxypyrazoleIXX, 1-benzoyl-3 A n n i . Calcrl. for C-i;sH:;N~O;%: S,10.9;. Found: K, anilino-5-pyrazolone, XXIV, and l-benzoyl-% I I I. $14, ..i h e oil formed in the reaction mixture, on trituration anilino-5-benzoyloxypyrazoIelXXV, were pre pared as new compounds and their structures first with water and then methanol, gave 0.6 g. of unestablished. changed 3-anilino-5-pyrazolone XVI.'? Pure l-acetyl-3-phenyl-3-pyrazolone, 11, melts Film-strip Test.--A sample (about 0.005 9.) of the compound to be tested and a n approximately equal weight of a t 127'. The compound reported in the literature p-aniinodimethylaniline hydrochloride are dissolved in 5 as melting a t 121' is contaminated with VI. The ml. of 3% sodium carbonate in a test-tube. A strip of diacetyl derivative of 3-phenyl-5-pyrazolone meltexposed photographic film ( e . E . , Rodalithj is immersed i n the solution and the test-tube shaken occasionally until, ing a t 8-1' is not 1,2-diacetyl-3-phenyl-5-pyrazowithin one t o five minutes, a high density of silver is de- lone, VII, but l-acetyl-3-phenyl-5-acetoxypyraveloped. The strip is then rinsed with running water for d e , V I I I . about one minute, and silver and silver halide are removed A migration of acetyl from nitrogen to oxygen hv shaking the strip in a mixture ( 5 ml. total) of equal was found to occur when 1-acetyl-X-phenpl-.jparts of solutions 1 and 2 . until the film is translucent. It pyrazolone, 11, was treated with pyridine, yielding i.s then washed in running water and inspected. 3-phenpl-5-acetoxypyrazo1el VI. Solution I : 25 g . uf potassium ferricyanide, 5 g. of potassium bromide, 5 g. of sodium carbonate, water to A migration of acyl from position 1 to position make 1 liter. Solution 2 : 200 g. of sodium thiosulfate, 2 was observed with several of the above-named ,i g of sodium carbonate, water to make 1 liter. pyrazoles. Summary The formation of dyes by color develop The acetylation and benzoylation of 3-phenyl- ment of a photographic film is described as a 5-pyrazolonc, I, and of 3-anilino-5-pyrazolone, test XST. were studied I
