Document 2JDr6mkb0KM11dZ9oLgywxjyb
E. I. DU PONT DE NEMOURS & COMPANY
256 VANDERPOOL STREET NEWARK, NEW JERSEY
Serial No. KN-70-3
Copy No.
14
r et ur n t o
JACKSON LABORATORY
FILE ROOM
NEWARK PLANT PIGMENT COLOR RESEARCH REPORT
SUBSTITUTED QUINACRIDONES FROM SUCCINYLSUCCINIC ESTER AND 2,6-DIETHYLANILINE
Period Covered May, 1969 to July, 1969 (Part Time)
FILE: 223.91 DATE: 2/17/70
NJ 14071
DUP050081910
KN-70-3
1. 2. 3. 4. 5.
6. 7. 8. 9.
10. 11. 12. 13.
14. 15.
Numerical Pile Research Office File, Newark 223.91 Newark Library File 223.91 M.Hunt/E.Gonick, Pigments, Wilmington W.S.Struve
F.F,Ehrich/E.F.Klenke/BB,Perkins/Newark Library P.J.Monahan, Newark (Vital Records) N.G.Fisher, Central Research Dept., Wilmington R.H.Wetzel/j.F .Maurer/J.W.Minnich/tf .A.West
M.C.Crossan, Newport Research File G.R.Aldridge Extra Extra
Extra Extra
NEWARK PLANT
PIGMENT COLORS RESEARCH REPORT
SUBJECTS SUBSTITUTED QUINACRIDONES FROM SUCCINYLSUCCINIC ESTER AND 2,S-DI2THYLANILINE
PERIOD COVERED : May, 1969 to July, 1969 (Part Time)
'V.SUBMITTED BY;:
R. ALDRIDGE
".17, / S'-sx tt-vAPPROVED BYs F.` F, EHRICH
DATE SUBMITTEDs 12/15/69 DATE RELEASED: 1/30/70.
ABSTRACT
The pyrolysis of diethyl 2,5-bis(2,6-diethylanilino)-3,6dihydroterephthalate in Dowtherm gave a mixture of 4,11-diethyldihydroquinacridone and 4,11-diethylquinacridone. In polyphosphoric acid 2,5-di(2,6-diethylanilino)terephthalic acid gave a mixture of diethy, triethyl, and tetraethyl quinacridones.
DUP050081911
TABLE OF CONTENTS
INTRODUCTION OBJECT OF INVESTIGATION PERIOD COVERED BY REPORT SUMMARY AND CONCLUSIONS PATENT STATUS DISCUSSION EXPERIMENTAL SUGGESTIONS FOR ADDITIONAL WORK NOTEBOOK REFERENCES
Page 1 I 1 1 2 2 3 6 6
DUP050081912
INTRODUCTION
Uhder conditions that mono-substituted anilines condense with succinylsuccinic ester (SSE) to give substituted dianilinodihydroterephthalate esters, the reaction of 2,6-diethylaniline (I) with SSE was carried out to determine if there was sufficient steric hindrance to prevent the reaction of the amino group in I with SSE. Diethyl 2,5 -bis (2,6--diethylan.il ino) -3,6 -dihydroterephthalate (II) was obtained in 90% yield showing there was little, if any, steric hindrance to the reaction of SSE with I.
OBJECT OF INVESTIGATION
To prepare and evaluate substituted quinacridones from II, and its corresponding terephthalic acid, 2,5-di(2,6-diethylanilino) terephthalic acid (III).
PERIOD COVERED BY REPORT
May, 1969 to July, 1969 (part time).
SUMMARY AND CONCLUSIONS
The pyrolysis of diethyl 2,5-bis (2,6-diethylanilino)-3,6dihydroterephthalate (11) in Dowtherm gave a mixture of 4,11diethyldihydroquinacridone (4,11-diethyl DQA), and 4,11-diethylquinacridone (4,11-diethyl QA) (see diagram below for numbering in quinacridone system).
2
4H
QUINACRIDONE (QA)
On oxidation with Sitol, this mixture gave 4,11-diethylQA as shown by its analysis, infrared spectrum, and X-ray crystallographic pattern. The cyclization of II to 4,11-diethylDQA (25-38% yield) requires the displacement of two ethyl groups either in the form of ethylene or diethyl ether (ethyl group in terminal ring combines with ethoxy group from ester group). Tests on the gas mixture from the pyrolysis reaction proved the presence of ethylene.
In polyphosphoric acid at 140-60, 2,5-di(2,6-diethylanilino) terephthalic acid gave a red pigment (IV), presumably a triethylquinacridone based on its elemental analysis. The mass spectrum of IV showed it to be a mixture of triethylquinacridone (3 parts), tetraethylquinacridone (2 parts), and diethylquinacridone (1 part). The formation of tri- and tetraethylquinacridones requires that the displaced ethyl groups migrate to new positions in the quinacridone ring.
The considerably greater solubility of IV in dimethylformamide and its extremely poor lightfastness (tint faded completely after
DUP050081913
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24 hours, Fadeometer exposure, slight fading in 4,11-diethyl QA tint after 120 hrs. Fadeometer exposure) in lithographic varnish versus 4,11-diethylQA suggest that the tri- and tetraethylquinacridones in IV may he substituted in the 1 and/or 5 and/or 6 positions. The assumption that 3,10- and 2,9-diethylquinacridones would have lightfastness as good as or better than 4,11-diethylQA is a reasonable one.
The lightfastness of 4,11-diethylQA (scarlet in color) is inferior to that of quinacridone.
PATENT STATUS
No filing action is planned.
DISCUSSION
The cyclization of II to 4,11-diethylDQA requires the displace
ment of either ethylene (2 moles) and ethanol (2 moles) or diethyl ether (2 moles). Similarly, the cyclization of di(n)butyl 2,5-di(2,6-diethylanilino)~3,6-dihydroterephthalate (C36H50N2O4) to
4,11-diethylDQA requires the displacement of either ethylene (2 moles) and n-butanol (2 moles) or n-butyl ethyl ether (2 moles)., i, i.e.,.
^rCS4,E22Ns0s + 2 Hac CH2 + 2 n-C^HgOH 4,11-diethylDQA ethylene n-butanol
c36H50Na4
^C24H22.N202 + 2 n-C4H9-O-.C2H5 n-butyl ethyl ether
The following evidence indicates that ethylene is formed in the pyrolysis of C3^H50N204 (ll-di(n)butyl ester) 1 the gases from the pyrolysis reaction on passage through a bromine in carbon tetrachloride solution discharge the bromine color without the evolution of hydrogen bromide, and the addition product, ethylene bromide, was shown to be present in the carbon tetrachloride solu tion by its conversion to a solid derivative, 1,2-di(2-naphthoxy) ethane. The presence of n-butanol in the distillate from the
pyrolysis of C36H50N2O4 was confirmed by , olfactory tests.
The first step in the postulated mechanism (page2a) is the formation of a ketene-eneamine intermediate and ethanol (or butanol). The second step involves an intramolecular addition of the -NC-e=C- unit associated with the center ring to the adjacent 2,6-diethylphenyl ring to form a pseudo-quinolone, which eliminates ethylene to form the substituted quinolone, V (enol form). V, then repeats the preceding steps to form 4,11-diethylDQA (enol form).
Unlike II, the pyrolysis of diethyl 2,5-bis(2,6-dimethylanilino)-3,6-dihydrofcerephthalate (VI) did not yield any 4,11-dimethyldihydroquinacridone or any Dowtherm-insoluble product. The failure of VI to form 4,11-dimethylDQA or related dihydroquinacridones is not surprising in view of the greater energy required to displace methyl groups than that required to displace ethyl groups from pseudo-aromatic systems.
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In polyphosphoric acid at 140-60, 2,5-di(2,6-diraethylanilino) terephthalic acid (v i i) gave a red pigment whose infrared spectrum was similar to, but not identical with, 4,11-diroethylquinacridone. The migration of ethyl or methyl groups during the ring closure of III or VII to tri- or tetraalkylguinacridones in polyphosphoric acid at 140-60 is not surprising in view of the rearrangement of 1,2,3,5-tetramethyl or 1,2,4,5-tetramethyl benzenes to 1,2,3,4tetramethyl benzene in cold concentrated sulfuric acid (Jacobsen rearrangement).
EXPERIMENTAL
The sample of 2,6-diethylaniline (I) used to prepare the 2,5di- (2,6-diethylanilino)dihydroterephthalate esters (diethyl and di-n-butyl) was a high quality sample since vapor phase chromato graphy of I on two different columns showed it to be substantially free of impurities. The supplier (Matheson, Coleman and Bell) affirmed its minimum purity to he 98%.
Preparation of Diethyl 2,5-Pi(2,6-diethvlanilino)-3,6-dihvdro-
terephthalate
! ~ 1914/31F
Charge to 3 liter flask: 76.8 g (0.30 mole) diethyl succinylsuccinate 1500 cc 2b alcohol
Blanket with nitrogen, and heat to 70 (incomplete solution). Add*
7.5 ml trifluoroacetic acid 134 g (0.90 mole) 2,6-diethyianiline The water formed in the reaction was removed by codistillation with ethanol (1200 cc in 3 hrs.). Cool, filter, slurry presscake with a sodium carbonate solution (10.8 g Na2C03 in 60 cc BfeO), stir, filter, wash with water until brilliant yellow free, and dry.
Yields 140 g (90%)
mp 169-70
Found;
C, 75.40 H, 8.30 N, 5.68
C32H4aNa04 req. C, 74.2 H, 8.1 N, 5.4
Preparation of Di-n-Butyl 2,5-Di(2.O-diethvlanilinoiS.e-dihvdro-
phtnalate
~~
1 ' 1914/50A
Found;
C, 75.32 H, 8.82 N, 4,77
C36H50N2O4 req. C, 75.2 a, 8.72 N, 4.88
Preparation of Diethyl 2,5-Di(2,6-dimethylanilino)-3,6-dihvdrotere-
phthalate
"
1914/41A
Found: C, 72.95 H, 7.57 N, 6.10
C2QH34N3O4 req, C, 72.8 H, 7.36 N, 6.06
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Preparation of Diethyl 2,5--D.i(2-ethylanilino)-3,6-dihydrotere>
phthalate
1914/46F
Foiand: C, 74.09 H, 7,55 N, 6.45
C2H34N204 req. C, 72.8 H, 7.36 Nf 6.06
Preparation of 2,5-Di (2,6-diethvlanilino)terephthalic Acid 1914/3IB
Charge to 1 liter flash 21.4 g {.041 mole) diethyl 2,5-di {2,6-diethylanilino)-3,6dihydroterephthalate 250 ml 2B alcohol 21.4 g Sitol
Stir, Add dilute sodium hydroxide solution (10 g in 100 cc H2O), reflux 901, dilute with hot water to 1 liter, and filter. Adjust pH of filtrate of 1-2 with 55 cc 5N HCl, filter, wash chloride ion free, and dry.
Yield; 9.3 g (bright red)
mp approx. 325`
Pound;
C, 72.97 H, 7.38 N, 6.17
C28H32N204 req* C, 73.0 H, 6.96 N, 6.09
Preparation of 2,5-Di (2,6-dimethvlanilino)terephthalic Acid
..................................
! ' 1914/41C
Pound* 202
Neutralization Equivalent Calc, for Ca4Ha4Na04 s 202
Preparation of 2/5-Di(2-ethvlanilino)terephthalic Acid 1914/53A
Pound:
C, 70.48 H, 5.83 N, 7.02
C24Ha4Na04 req. C, 71.3 H, 5,94 N, 6.93
Preparation of 4,11 - Diethyldihvdrocruinacridone
1914/46P
Diethyl 2,5-di(2-ethylanilino-3,6-dihydroterephthalate 4,11- (c 2H5)2DQA
Pound:
C, 78,10 H, 5,91 H, 7.46
Ca4H2gNa0a req. C, 77.8 H, 5.95 N, 7.57
Preparation of 4,11-diethvlauinacridone
1914/53D2
2,5-Di(2-ethylanilino)terephthalic Acid --4t11-diethylQA PPA
The product was acid recrystallized, and then recrystallized from dimethylformarnide.
Pound:
C, 75.88 H, 5.43 N, 7.60
Ca4HgQHa0a req. C, 78.2 H, 5.44 N, 7.61
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Preoaration of 4,11-Diethvlquinacridone
1914/57B
4# 11-Diethyl DQA ----------4,11-diethyl QA Sitol
Pound;
C/ 77.16 H, 5.73 E, 7.67
Cs4H20Na02 req. C, 78.2 H, 5.44 E, 7.61
It spectra of 57B and 53D2 are identical except for peak at 6.55|X in 57B which is absent from 53D2. The location of this peak suggests the presence of some 4,11-diethyl DQA in 57B.
Pvrolvsls of Il-diethyl ester
1914/40A
250 cc Dowtherm (under Na) Heated to reflux. Add portionwise 21.4 g jl-diethyl ester Refluxed 1 hr., cooled red-brown suspension to 30, washed Dowtherm free with methanol/ and dried.
filtered/
Yield: 3.8 g Color: red
% Yield Of 4/11-diethyl DQA =25
Oxidation of this product with Sitol-C2H5OH-NaOH-H2O followed by two acid recrystallizations gave 4/11-dietnyl QA. Recrystal lization of this product from dimethylformamide gave an analytically pure sample.
Pound: C, 78.10 H, 5.42
E, 7.61
C24H20NaO2 req. C, 78.2 H/ 5.44
N/ 7.61
The infrared spectrum and x-ray pattern of this product are identi cal with the spectrum and c rystallographic pattern of 4/11-diethyl
QA (1914/53D2) prepared from 2,5-di(2-ethylanilino)terephthalic
acid by ring closure in polyphosphoric acid.
Ring Closure of 2,5-Pi(2,6-diethvlanilino)terephthalic Acid
..........................................
1 1914/31C
4.6 g (.01 mole) III
92 g.
polyphosphoric acid
Heated at 140-60 for 2 hrs./ cooled to 70, added water (180 cc) at 70-90 drowned in 1 1 water/ filtered/ washed with water/ slurried with 0.1 N sodium hydroxide solution/ filtered/ washed brilliant yellow free, and dried.
Yields 3.6 g Colors red
This product was acid recrystallized twice and then recrystal lized from dimethylformamide.
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Pound:
C* 78.40 H, 6,23 N, 6,94
C26Ha4N20a req. C/ 78.8 Itriethyl QA) H, 6.06
N, 7,07
C2*N2gN2O2 req. C/ 78,2
(diethyl QA)
H, 5.44
N, 7.61
The mass spectrum of this product shows it to he a mixture of triethylquinacridone (3 parts), tetraethylquinacridone (2 parts), and diethylquinacridone (1 part).
SUGGESTIONS FOR ADDITIONAL WORK
The solubility of the mixture of tri- and tetraethylquinacridones is believed to be greater than that of any other quinacridone. Quinacridone photochemical studies in organic solvents that require solutions and not suspensions are a possibility.
NOTEBOOK REFERENCES
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