CA1082708A - 3- (diphenylamino) phthalides - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
3-[4-(Disubstituted-amino)phenyl]- or 3-[(9-julolidin-yl))-3-(diphenylamino)phthalides useful as color formers in pres-sure-sensitive and thermal marking systems are prepared by reac-tion of 2-14-(disubstituted-amino)benzoyl] or (9-julolidinyl-carbonyl)benzoic acids with diphenylamines.

Description

10 ~ ~'7~ ~

This invention relates to 3~substituted-3-~diphenylamino)phthalides u~eful as color form0rs in pressure-~ensitive carbonless duplicating systems, ~hermal marking system~ and hectographic or spirit-reproducing cbpy~ng system~t to processe~ for the prepar~tion therflof5 and to pressure-sen~itive duplicating ~ystems, thermal marking ~ystem~ and hectographic copying systems con~ining the same.
Several cla~ses o organic compounds of widely di-ver~e structural types are known to be useful a~ color formere ~or carbon;ess duplicating sy6tems. Among the more widely recognized classes, there may be named phenothiazines, for example, benzoyl leuco methylene blue; fluorans, for example, 2'-anllino-6'-diethylaminofluoran; phthalides, the class wlth which this invention is concerned, for examplo, crystal violet lactone; and various other types of color formers currently employed in commercially accepted carbon-less duplicating systems. Typical of the many such sy3tems taught ln the prior art are those described in U.S. Patents

2,712,507, 2,800,4S7 and 3~041,289~
Many of the color formers in the prior art suffer one or more dieadvantages ~uch as low tinctorial strength, poor l$ght stability, low resistance to ~ublimation and low solubility in common organic solvent , the latter disadvan-2S tage thus requiring the use of specialized and expensive -.

. .

iLOti ;~'70~

801vent8 in order to obtain microencapeulated 801ution8 Of 8ufficient concentration for u8e in pr~8ur8-8ensitive copying 8y8tem8. Other prior art includes U.S. Pat~nt8

3,736,168 and 3,491,112 and Japane3~ Patent Publication No.
71/4616.
R. Valters and V. ~8iekuro in Khim. G~terot~ikl.
Soedin. 1975, (llJ 1476-8 di~CU88 ring-chain tautomeri8m in 3-(N,N-diphenylamino)-3-phanylphthalide but di~cloee no utility for the compound.
Thi~ invention relate8 to compound9 having Formula I

(Q)n ~ ~

Yl Y2 Formula I
wherein Q i9 ai-lower-alkylamino, nitro, halo or COX, where X i8 hydroxyl, benzyloxy, alkoxy having frcm 1 to 18 carbon atoms or OM where M i9 an alkali metal cation, an ammoniUm cation or a mono-, di- or tri-alkylammonium cation having from 1 to 18 carbon atom8;
n is O; or 1 when Q i8 di-lower alkylamino, nitro or COX; or from 1 to 4 when Q i8 halo;
Yl, Y2, Y3 and Y4 are the 8ame or different and are hydrogen, halo, hydroxyl, lower-alkoxy, alkyl having from 1 to 9 S

} ~ ;1 V ~

carbon atoms, phenyl-lower-alkyl, COOR4 or NR5R6, where R4 and R5 are hydrogen or low~r-alkyl and R6 is hydrogen, lower-alkyl, cycloalkyl having from S to 7 carbon atoms, or lower alkanoyl; Z i8 ~ j A3~R2 , l ll and 9-julolidinyl R8Rg ~ R7 in which:
R is hydrogen or non-tertiary alkyl having from l to 4 carbon atoms;
Rl is hydrogen, or non-tertiary alkyl having from 1 to 18 carbon atoms;
R2 i9 hydrogen, phenyl or non-tertiary alkyl having from 1 to 4 carbon atoms;
R3 is hydrogen, non-tertiary alkyl having from l to

4 carbon atoms or non-tertiary alkoxy having from l to 4 car-~on atoms;
R7 is hydrogen, halo, lower-alkyl, lower-alkoxy or di-lower-alkylamino;
R8 is lower-alkyl; and Rg is lower-alkyl, benzyl, phenyl or phenyl sub-stituted with a lower-alkyl or lower-alkoxy group.
The compounds are useful as color formers in pres-~ure-sensitive carbonless dupli¢ating systems, thermal marking ~ystems and hectographic copying systems.

Particularly embodiment~ relat~ to compounds having Formula I
wherein Q, n~ Yl, Y2, ~3 and Y4 have the previously given meanings and 2 is 3 ~ ~ ~ ~2Rg~- l`` ~

Rl, R2, R3, R7, R~ and Rg having the previously given meanings. Preferred compound~ within the ambit of this particular embodiment are those wherein:
a) n is O;
b) n is 1 and Q is di-lower-alkylamino or COX
where X has the previously given meanings; and c) n is 4 and Q is halo; especially 3-~N-(4-ethoxy-phenyl)-N-phenylamino~-3- ~-ethyl-2-methyl-3-indolyl)phthalide, 3-(diphenylamino~-3-~1-ethyl-2-methyl-3-indolyl)phthalide, 3-~1-ethyl-2-methyl-3-indolyl3-3-~N-phenyl-N-m-tolylamino)-phthalide, 3-~1-ethyl-2-methyl-3- ::
indolyl)-3-~N,N-bis(3-ethyl-5-nonylphenyl)amino]phthalide,

5-(and 6-)carboxy-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(l-ethyl-2-methyl-3-indolyl~-phthalide, 3-[N-¢4-ethoxyphenyl)-2n N-phenylamino]-3-(1.-ethyl-2-methyl-3-indolyl)-5-~and 6-) methoxycarbonylphthalide, 5-~and 6-ethoxycarbonyl 3 { N -t4--ethoxyphenyl)- N -phenylamino] - 3 ~
ethyl-2-methyl-3-indolyl~phthalide, 3-[N-~4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3-indolyl)-5-~and 6-)-n-octyloxy-carbonylphthalide, 5-~and 6-)benzyloxycarbonyl-3-N-[4-(ethoxy-phenyl)-N-phenylamino]-3- ~-ethyl-2-methyl-3-indolyl)phthaliae, 4,5,6,7-tetrachloro-3-[N-~4-ethoxyphenyl)-. -5-. ..

.
` ' ' - `
., ~ .
`': :'~ `, ':: `

N-phenylamino]-3-(ethyl-2-methyl-3-indolyl)phthalide, 3-(l-ethyl-2-methyl-3-indol~ 3- [N,N-bi8- ~4-octylphenyl)-amino]phthalide, 3-[4-(dimethylamino~phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino~-phthalid~; 3-~4-dimethyl-amino)phenyl]-3-[N-~4-isopropoxyphenyl)-N-phenylamino]-phthalide; 4,5,6,7-tetrachloro-3-[4-~dimethylamino) phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino~phthalide;
3-14-(diethYlamino)-2-methylphonyl~-3-lN-~4-ethoxyphenyl)-N-phenylamino]amino]phthalide; 3 ~4-~dimethylamino)phenyl]-3-~N,N-~is-(4-octylphenyl)aminQ~phthalid2; 6-~dimethylamino)-3-[4-(dimethylamino)phenyl~-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide; 3-[4-(dimethylamino)-phenyl]-3-(N,N-diphenylamino)phthalide; 6-(dimethylamino)-3-[4-(dimethylamino)phenyl]-3-[N,N-bis(4-octylphenyl)amino]-phthalide; 3-[4-(ethylbenzylamino)phenyl]-3-~N-(4-ethoxy-phenyl)-N-phenylaminolphthalide and 3-[4-~diethylamino)-2-methylphenyl]-3-{N,N-bis~4-~dimethylamino)phenyl]amino}-phthali~e.
One can prepare the compounds of Formula I, by a process which comprises reacting a 2-sub~tituted benzoic acid havin~ Formula II

,~02H
(Q) ~ 11 ~=0 ~ Formula II

with a diarylamine having Formula III

Yl ~ ~ Y3 Y2 ~ ~ 4 Formula III

-6-'7~3~
in the presence of the anhydride of an alkanoic acid having from 2 to 5 carbon atoms, and an organic baee; where in Formulas II and III, Z, n, Yl, Y2, 3, 4 previously given meanings and Q is selected from the group consisting of di--lower-alkyl-amino, nitro, halo and COX
where X is hydroxy, benzyloxy or alkoxy having from 1 to 18 carbon atom~ .
Another process for producing the compounds of Formula I, compri~es reacting a 2-substituted benzoic acid 1~ of Formula II, with an inorganic acid chloride which is thion~l chloride, phosphorus oxychloride, phosphorus tri-chloridè or phosphorus pentachloride, followed by reaction of the resulting product with a diarylamine of Formula III, in the presence of an organic base; where in Formulas II
and III, Z, O, n, Yl, Y2~ Y3 and Y4 have the meanings given in the preceding paragraph.
A further process for preparing the compounds of Formula I, wherein Z is ~L

comprises reacting a phthalamic acid having Formula IV

~,~ /C02H
(Q) n~ 1-l ~ 4 ~/
.~, Y~ 2 _7_ Formula IV

.. ~.,. .~., . , -10~;~'70~
with an indole having Formula V

Formula V
in the presence of the anhydride of an alkanoic acid having from 2 to 5 carbon atoms; where in Formulas IV and V Q, n, Yl, Y2, y3, v4, Rl, R2 and R3 have the abo~e-given meanings The present invention also deals with a pressure-sensitive carbonless duplicating system, thermal marking s~stem or hectographic copying system containing a color-forming sub~tance comprising a compound having Formula I.
A particular smbodiment resides in a pressure-sensitive transfer sheet~ adapted for use with a receiving sheet having an electron accepting layer, comprising a support sheet coated on one side with a layer of pressure-rupturable microcapsules, said microcapsules containing a liquid solution of a color forming substance comprising at least one compound having Formula I~ Another particular embodiment resides in a heat responsi~e record material comprising a support sheet coated on one side with a layer containing a mixture comprising at least one color-forming compound having Formula I and an acidic developer arranged such that applica-tion of heat will produce a mark-forming reaction between the color-forming compound and the acidic developer~
A further particular embodiment resides in a hecto-graphic or spirit reproducing copying system comprising a tran~fer sheet coated on one side with a layer containing a color-forming substance comprising at least one compound having Formula I, wherein n is l and Q is COX where X is ,...... . ~ , . .
~, . .

~ '7~ ~
OM and M ha~ the previously given meanings.
As uced herein the term "halo" includes chloro,fluoro, bromo and iodoO Chloro iB the preferred halo sub-stituent because of the relatively low cost and ea~e of pre-paration of the required chloro-substituted intermediates and because the other halogens offer no particular advantage6 over chloro. However the other a~ove-named halo aubstituents are also satisfactory.
The termQ "lower-alkyl, lower-alkoxy and di-lower-alkylamino" denote saturated, acyclic groups having from 1te 4 carbon atoms which may be straight or branched as exemplified by methyl, ethyl, pr~pyl, isopropyl, butyl, sec-butyl, isobutyl, ert-butyl, methoxy, ethoxy, propoxy, i80-propoxy, butoxy, sec-butoxy, i~obutoxy, tert-butoxy, dimeth-ylamino, diethylamino, ethylmethylamino, dipropylamino,dibutylamino, isobutylmethylamino, di-tert-butylamlno and the like.
A~ used herein the term "cycloalkyl having from 5 to 7 carbon atoms" include6 cyclopentyl, cyclohexyl and cycloheptyl.
The term "lower alkanoyl" denotes saturated acyclic acyl groupR having from 1 to 5 caxbon atoms which may be straight or branched as exemplified by formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, 2-methylbutyryl, isovaleryl, pivalyl and the likeO
The term "phenyl-lower-alkyl" include~ benzyl, 2-phenylethyl, 2-phenylpropyl, 3-phenylpropyl, l-phonyl-butyl, 2,2-dimethyl-2-phenylethyl and the like. If desired the phenyl group may contain a lower alkyl or lower alkoxy substituentO

~ :~
-{r ~

, ~ ' '~ ' .lV~;~710~
The term "alkoxy having from 1 to 18 carbon atoms"
includes, in addition to the above-noted lower-alkoxy groups, saturated, acyclic, straight or branched-chain groups such as n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyl-oxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, n-pentadecyloxy, n-hexahecyloxy, n-hepta-decyloxy, n-octadecyloxy, l-methylpentyloxy, 2,2-dimethyl-butyloxy, 2-methylhexyloxy, 1,4-dimethylpentyloxy, 3-ethyl-pentyloxy, 2-methylheptyloxy, l-ethylhexyloxy, 2-propyl-10pentyloxy, 2-methyl-3-ethylpentyloxy, 1,3,5-trimethylhexyl-oxy, l,S-dimethyl-4-ethylhexyloxy, 5-methyl-2-butylhexyl-oxy-2-propylnonyloxy, 2-butyloctyloxy, l,l-dimethylundecyl-oxy, 2-pentylnonyloxy, 1,2-dimethyltetradecyloxy, l,l-dimeth-yl-pentadecyloxy and the like 15As used herein the term "alkyl having from 1 to 9 carbon atoms" denotes saturated monovalent straight or branched chain aliphatic hydrocarbon radicals including meth-yl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, amYl, l-methylbutyl, 3-methylbutyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, 2-ethylhexyl, nonyl, 3-ethyl-heptyl and the like.
The term "non-tertiary alkyl having from 1 to 18 carbon atomsl includes, in addition to the above-named alkyl groups having from 1 to 9 carbon atoms, excluding o~ course any tertiary alkyl groups, saturated, monovalent, straight or branched-chain aliphatic hydrocarbon radicals such as n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl, 1,3,5-trimethylhexyl, 1,5-dimethyl-4-ethylhexyl, 5-methyl-2-butyl-3~ hex~l, 2-propylnonyl, 2-butyloctyl, 2-pentylnonyl, 1,2-dimeth-, yl-tetradecyl, and the like.
As used herein the term "alkali metal" includes lithium, sodium and potassium.
The term "mono-, di~ or tri-alkylammonium cation"
includes ammonium cations substitute by from 1 to 3 alkyl group~ as above described, The al~yl groups can be the same or different provided the ammonium cation contain~ no more than 18 carbon atoms. As examples there can be named methyl-ammonium, t-butylammonium, t-octylammDnium, n-dodecylammonium, n-octadecylammDnium, di-n-butylammonium, di-n-nonylammonium, isopropyl-n-butyl-ammonium, dimethyl-n-butylammonium, tri-ethylammonium, N-ethyl-N,N-diisopropylammonium, tributylammonium, di-n-butyl-octylanmonium and the like.
The term "9-3ulolidinyl" of course refers to the radical having the formula Anhydrides of alkanoic acids of two to five carbon atoms include acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anh~dride, valeric anhydride, iso-valeric anhydride, ~-methylbutyric anhydride, pivalic anhydr-ide and the like. Acetic anhydride is preferred because of i~s low oost and high reactivity, however the other above-named anhydrides are also satisfactory.
Organic bases include pyridine, collidine, tri-lower-alkyl amines, urea, diarylamines of Formula IV, herein-:, .. . . .:

' . ' :

~ '7~U~

above and the like~ Because of their low cost and readyavailability pyridlne and urea are preferred.
In accordance with one process the compounds having Formula I, are obtained by reacting approximately equimolar amounts of a 2-substituted benzoic acid of Formula II and a diarylamine of Formula III in the anhydr-ide of an alkanoic acid having from two to five carbon atoms, such as acetic anhydride, with or without an inert diluent and in the presence of an organic base, for example pyridine or urea, at a temperature of from about 0 to 1005C. for from approximately 10 minutes to 24 hours. The reaction is usually carried out in the absence of an inert diluent at about 20 to 40C. for approximately 0.5 to 2 hours. If desired an excess of the diarylamine reactant can be employed as the organic base~ The product thus obtained can be isolated by filtration if it is insoluble in the reaction medium or by dilution of the reaction medium with a miscible solvent in which the product is insoluble such as a lower-alkanol or low molecular weight hydrocarbon for example iso-propyl alcohol or hexane or a mixture of these in order toeffect precipitation of the product. Alternatively, the reaction mixture can be poured into aqueous base such as dilute ammonium hydroxide, sodium hydroxide, sodium carb-onate or sodium bicarbonate and the product extracted with an organic solvent such as benzene or tolue~e followed by evaporation of the organic solvent leaving the pxoduct as a residue. The product once isolated can be purified by conventional means such as trituration or recrystallization from a suitable solvent.
3~ In accordance with a second process the compounds '708 of Formula I, can be prepared in two steps which compris~
first reactin~ a 2-substituted benzoic acid of Formula II, with an excess of an organic acid chloride such as thionyl chloride, phosphorus oxychloride, phosphorus trichloride or phosphorus pentachloride with or without an inert diluent such as benzene, toluene, chloroform or 1,2-dichloro-ethane, at 20 to 30C. for about 0.5 to 2 hours; and following removal of excess inorganic acid chloride, reac-tion of the resulting product which while not having been isolated is presumed to be a halide having Formula VI

p (Q)n I ~ P
'"' '``>~

Formula VI
in which ~, n and Z have meanings previously given in Formula II, with a diarylamine Of Formula III, hereinabove in an inert solvent in the presence of an organic base as pre~iously described at a temperature in the range of 0 to 80C. for about 1 to 48 hours, The product can be isolated and purified in the manner previously described.
In accordance with a urther process the compounds having Formula I, wherein Z is r'~
R3 ~" ~

`R2 ~an be prepared by reacting a phthalamic acid of Formula IV
with an indole of Formula V in the anhydride of an alkanoic - , . ~ .
-:, -.. , .
' ' `'-~ ' ` '`' ` '' " ' ~' '" ' ' '~ , : ' , . . . . ..

"7(~

acid having from two to five carbon atoms, such as acetic anhydride, w~th or without an inert diluent and optionally in the presence of an organic base, for example pyridine or urea, at a temperature of from 0 to 100C. for from approximately 1 to 24 hoursO The reaction is usually carried out at about 20 to 40C. for approximately 2 to 12 hours. The product so-obtained can be isolated and purified in accordance with the above-described procedures.
When preparing compounds of Formula I, wherein Q
is COX and X is benzyloxy, alkoxy having from 1 to 18 carbon atoms or OM where M is an alkali metal cation, an ammonium cation or a mono-, di- or trialkylammonium cation having from 1 to 18 carbon atoms it is ordinarily preferred to first pre-pare the compound of Formula I, wherein Q is COOH followed by conversion of the carboxyl group to the desired ester, alkali metal salt or ammonium salt in accordance with conventional procedures.
Some of the 2-substituted benzoic acids of Formula II required as starting materials in the preparation o the products of Formula I are known, for example as disclosed in U~S. Patent 3,812,146, issued May 21, 1974, German Offenlegungsschrift 2,423,534, published December 12, 1974, Journal of the Chemical Society 107, 885 ~1915~ and Chemical Abstracts 83, 77938h ~1975~ Those previously not known can be prepared in accordance with the procedures described for the preparation of the known compounds, e.g. as disclosed in British Patent 1,435,179, The 2-substituted benzoic acids are prepared by reacting a phthalic anhydride having Formula VII

,i ' ~

'7U~
!
~ ``~
(Q)~ o ~ ..

Formula VII
with an appropriate indole of Formula VI, a pyrrole of Formula VIII, a carbazole of Formula IX, an aniline of Formula X or julolidine, R8Rg Formula VIII rFormula IX Formula X
and n in Formula VII having the meanings given above in ~ormula II and R, R7, R8 and Rg in Formulas VIII, IX and ;~
X having the previously given meanings, in the presence of a Lewis acid, for example, aluminum chloride or zinc chloride, with a diluent such as benzene, chlorobenzene or o-dichloro-benzene at a temperature of about 0 to 100C. The reaction is conveniently carried out in benzene in the presence of aluminum chloride at about 0 to 25C. Alternatively, the more reactive indoles ~Formula V~ can be reacted with the phthalic anhydrides ~Formula VII) in the absence of a Lewis acid by simply heating the reactants together in an inert solvent at about 80 to 150C.
It will, of course, be appreciated that reaction of an unsymmetrically substituted phthalic anhydride (~ormula VII) with an indole, p~rrole, carbazole~ aniline (Formula V, VIII, IX or X~ or julolidine can produce isomers or a mixture of isomers of 2-2-CO-benzoic acids ~ormula II~. :

. . - . . : . . -,. - . , . . - : . .
.. ~, ,, . . .
;. - ~ . . - : : . . ' , For example, reactlon of a 3-substituted phthalic anhydride tFormula VII where n i9 l and Q occupies position 31 with an indole, pyrrole, carbazole, aniline or julolidine can produce either a 3- or 6-~substituted 2-Z-CO-benzoic acid ~Formula II where n i5 l and Q occupies either position 3 or position 6) or a mixture of these. Similarly, a 4-substituted phthalic anhydride (Formula VII where n is l and Q occupies position 4) can produce either a 4- or a 5-substituted 2-Z-CO-benzoic acid ~Formula II, where n is l and Q occupies position 4 or position 5) or a mixture of these. The mixture of isomeric 2-Z-CO-benzoic acids can be separated by conventional means such as fractional crystallization or ~hromatography. Alter-natively, the isomeric mixtures can be reacted directly with appropriate diarylamines of Formula III to produce isomeric mixtures o~ phthalides of Formula I. Thus reaction of a mixture of 3- and 6-substituted 2-Z-CO-benzoic acids ~Formula II where n is l and Q occupies position 3 or 6) with a diarylamine of Formula III will produce a mixture of 4- and

7-substituted phthalides ~ormula I where n is l and Q
occupies position 4 or 7~; and in like fashion a mixture of 4- and 5-substituted 2-Z-CO-benzoic acids (Formula II where n is 1 and Q oacupies position 4 or 5~ will produce a mixture of 5- and 6-substituted phthalides ~ormula I where n is l and Q occupies position 5 or 6~. The mixtures of phthalides can, if desired, be separated by conventional means or simply and preferably used as mixtures in the practice of ~his inven-tion.
The diarylamines of Formula III which are also required as starting materials in the processes of the 0 invention belong to a well known class of compounds and '7(~

are either commercially available or readily obtained byconventional procedures well known in the art~
The novel compounds of Formula I hereinabove are essentially colorless in the depicted form. When contacted with an acidic medium, for example silica gel or one of the types ordinarily employed in pressure-sensitive carbonless duplicating systems such as silton clay or phenolic resins the compounds of Formula I develop a yellow to black colored image of good to excellent tinctorial strength, and possess- -ing excellent light stability, resistance to sublimation and xerographic copiabilityO The compounds are thus highly suitable for use as colorless precursors, that is color-forming substances in pressure-sensitive carbonless duplica-ting systems, The compounds which produce a yellow to red color can be used as toners in admixture with other color formers to produce images of a neutral shade which desirably are readily copiable by xerographic means. The compounds of ~ormula I wherein at least one of Yl and Y2 and at least one of ~3 and Y4 are simultaneously di-lower-alkyl~mino develop a brown to grape image when contacted with an acidic medium and are accordingly of particular value as color precursors. Moreover, the compounds of Formula I, in par-ticular those wherein n is 1~ Q is COX and X is alkoxy ;:
having from 1 to 18 carbon atoms, or those where one or more .
of Yl, Y2, Y3 and Y4 are alkyl of 1 to 9 carbon atoms, have enhanced solubility in common and inexpensive organic solvents such as odorless mineral spirits, kerosene, vege-tablè oils and the like; and those wherein n is 1, Q is COX
and X is OM in which M has the previously given meaning are soluble in water and lower-alkanols thereby avoiding the - - .

-~o~ v~

need for more expenslve, speclalized solvents such as poly-halogenated or alk~lated biphenyls which have ordinarily been used to prepare microencapsulated solutions of the color formers of the prior art~
The compounds of this invention may be incorporated in any of the commercially accepted systems known in the carbonless duplicating art~ A typical technique for such application is as follows~ Solutions containing one or more colorless precursor compounds of Formula I, optionally in admixture with other color formers, in suitable solvents are microencapsulated by well-known procedures for example as described in U,Sc Patent 3~649~649O The microcapsules are coated on the reverse side of a transfer sheet with the aid of a suitable binder and the coated transfer sheet is then assembled in a manifold with the microcapsule coated side in contact with a receiving sheet coated with an electron accepting substance~ ~or example, silton clay or a phenolic resin, Application of pressure to the manifold such as that exerted by a stylus~ typewriter or other form of writing or printing causes the capsules on the reverse side to rupture~ The solution of the color former released ~rom the ruptured microcapsules flows to the receiving sheet and on contact with the acidic medium thereon forms a yellow to red colored image of good tinctorial strength~ It is, of course, obvious that variants of this mode of application can be utilizedQ For example, the receiving sheet in a manifold can alternatively be coated with the subject com- :
pounds and the acidic developing agent can be contained in microcapsules applied to the reverse side of the top sheet :. 30 in the manifold: or the receiving sheet can be coated with a mixture containing both the acidic developing agent and the microencapsulated color former.
It has also been found that when the compounds of Formula I are intimately mixed with an acidic developer of the type generally employed in thermal papers such as described in U.S. Patent 3,539,375, that is, paper which produce a colored image when contacted with a heated stylus or heated t~pe, for example, bisphenol A, heating of the mixture produces a colored image of varying shades from yellow to purple depending on the particular compound of the invention employed. The ability of the compounds of ~ormula ~ to form a deep color when heated in admixture with an acidic developer such as bisphenol A, makes them useful in thermal paper marking systems, either where an original or a duplicate copy is prepared by contacting the thermal paper with a heated stylus or heated type in any of the methods generally known in the art. -The compounds of this invention which are soluble in water and lower-alkanols may be incorporated in any of .
the commercial hectographic or spirit-reproducing copying systems such as described in British Patent 1,427,318. In ~-such systems a transfer sheet coated on one side with a layer containing one or more water- or lower alkanol-soluble color formers of ~ormula I is placed with its coated surface against one surface of a master paper which is then typed, written or marked on, causing transfer of the coating as a substantially colorless reverse image to the master paper at the points where the transfer sheet and master paper have been pressed togetherD The master paper is then brought ~;~ 30 into contact with a succession of sheets of paper moistened 7V~

with a suitable spirit~reproduclng fluid such as ethanol.
The fluid dissolves a part of the color former and transfers it to each paper sheet where it combines with an electron-accepting substance, to give a yellow to red colored image which duplicates the original typing or writing on the master paper.
The molecular structures of the compounds of this invention were assigned on the basis of the modes of synthesis, elemental analysis and study of their infrared, nuclear magnetic resonance, and mass spectra.
The following examples will further illustrate the invention without, however, limiting it thereto.
EXAMPLE I
A. A mixture containing 24 g. of 2~ ethyl-2-methyl-3-indolylcarbonyl)benzoic acid, 16.5 g~ of 4-ethoxy-N-phenyl-aniline, 7 ml~ of pyridine and 70 ml. of acetic anhydride was stirred 1 hrb at room temperature Dilution with 30 ml.
of 2-propanol and 100 mlO of ligroin produced no precipitate.
The reaction mixture was therefore poured into 10% aqueous 2n ammonia and the product was extracted with toluene. The organic extracts were washed with water and saturated aqueous sodium chloride and evaporated to dryness under vacuum. Trituration of the residue with ligroin afforded 25~3 g. of 3-~(4 ethoxyphenyl~ N-phenylamino~-3-~1-ethyl-2-methyl-3-indolyl)phthalide, m,p~ 110-135C. Recrystalliza-tion of an analytical sample from 2-propanol-ligroin provided colorless crystals, m p. 161-163~C. A toluene solution of the product contacted with acidic clay or phenolic resin developed a yellow colored imageO
B. A mixture containing 7O86 g. ~0~02 mole) of 2- ~-., , . ., ,, ., - , 7(~

ethyl-2-methyl-3-indolylcarbor.yl)benzoic acid, 6.38 g. ~0.03 mole) of 4-ethoxy-N-phenylaniline and 12 ml~ of acetic anhydr-ide was stirred overnight at room temperatur~ and then poured into 200 ml. of 10% aqueous sodium hydroxide and 100 ml. of toluene. After stirring 1 hr. the lay~r~ were separated.
The toluene layer was dried over anhydrou6 ~odium sulfatQ, treated with decolorizing oarbon and filter~d The filtrate was concentrated to 5Q ml. and slowly diluted with 900 ml.
of hexane. The precipitated product was collected, washed with hexane and dried to give 6.0 g. of product essentially identical to the product of part A above.
~XAMP~ 2 A. A mixture containing 3cl g. of 2~ ethyl-2-methyl-3-indolylcarbonyl)benzoic acid, 5 g. of 3,3'-diethyl-5,5'-di-nonyldiphenylamine, 10 ml. of acetic anhydride and 1 mlO
of pyridine was stirred 1 hr. at room temperature and then poured into 10% aqueous sodium hydroxide and the product extracted with toluene. The toluene extracts were dried over anhydrous sodium sulfate and evaporated to dryness under vacuum. Trituration of the residue with ligroin and 2-propanol afforded 0.8 g. of 3-[N,N-bis-~3-ethyl-5-nonylphenyl)amino-]3-~1-ethyl-2-methyl-3-indolyl)phthalide, m.p. 76-90C. ~dec.). A toluene solution of the product contacted with acidic clay or phenolic resin d~veloped a red colored image.
Bo A mixture containing 6.2 g. of 2-~1-ethyl-2-meth-yl-3-indolylcarbonyl)benzoic acid, 903 g. of 3,3'-diethyl-5,5'-di-nonyldiphenylamine, 25 mlO of acetic anhydride and 1 g. of urea was stirred 2 hrs. at room temperature and then 0 poured into 5% aqueous ammonium hydroxide and extracted with toluene~ The organic extracts were dried over anhydrous sodium sulfate and evapo~ated to dryness under vacuum. The residue was triturated with cyclohexane to give 4.96 g. of product essentially identical to the product of part A above.
EXAM
A, A stirred solution containing 48.0 9. ~0O250 mole) of trimellitic anhydride and 45O0 g~ ~0.314 mole) of l-ethyl-2-methylindole in 350 ml~ of 1,2-dichloroethane was heated 2 hrsO under refluxO The reaction mixture was allowed to cool to room temperature and the precipitated solid was collected, washed with 1~2-dichloroethane and dried to give 66.0 g.
of a mixture of 4- and 5 carboxy-2~ ethyl-2-methyl-3~
indolyl-carbonyl~benzoic acid, mOp~ 198-201C. This material was used in subsequent reactions without further purification.
B~ A mixture containing 7O0 gO of 4-¢and 5-)carboxy-2-~1-ethyl-2 methyl~3YindoLylcarbonyl~benzoic acid, 4.3 g. of 4-ethoxy-N-phenylaniline, 25 mlO of acetic anhydride and ~-2 mlO of pyridine was stirred 2 hrs~ at room temperature.
Dilution with 20 mlO o 2-propanol and 100 ml. of ligroin produced no precipitateO The mixture was therefore poured into toluene and the product extracted with 5% aqueous ammonia~ The aqueous alkaline extracts were neutralized with 3N hydrochloric acidO The resulting precipitate was collec-ted, washed with water and dried to give 5.6 g. of 5-land 6-)carboxy-3-~NYt4-ethoxyphenyll-N-phenylamino~-3-~l-ethyl-2-methyl-3-indolyljphthalide~ mOpO 145-148C.
CO To a stirred solution containing 2 g. of the above acid in 30 ml~ o~ acetone was added 2 ml. t-octylamine. After stirring 10 minutes the mixture was diluted with 200 ml. of hexaneO The solvents were decanted and the residue was tri-;"7~3~

turated with hexane to give 1 8 g~ of t-octylammlonium 3-~N-(4-ethoxyphenyl)-N-phenylaminv~-3-~1-ethyl-2-methyl-3-indol-yl)-phthalide-5-(and 6-)carboxylate, m~p 141C. ~dec.lO

To a re~luxing mixture containing 5.5 g. of 5-(and 6-)car~oxy-3-[N-~4-ethoxyphenyl~-N phenylamino]-3~
ethyl-2-methyl-3~indolyl~phthalide, 3 g~ of potassium carb-onate and 150 ml~ of acetone was added 4 g~ of dimethyl-sulfate, A~ter heating 1 hr~ under reflux the mixture was poured into 300 ml. of 5~ aqueous ammonia and extracted with 400 mlO of tolueneO The toluene extracts were washed with water and saturated aqueous sodium chloride and evap-oratèd to dryness~ Trituration of the residue with ligroin afforded 0~6 g of 5-~and 6-)methoxycarbonyl-3-[N-~4-ethoxy-phenyl)-N-phenylaminoJ 3~ ethyl-2-methyl-3-indolyl) phthalide as a tan solid~ m.p~ 79-84C (decO)O A toluene solution of the product contacted with acidic clay or phenolic resin developed a yellow orange colored image~

A mixture containing 3O0 g of 5-~and 6-~carboxy-3-lN-(4-ethox~phenyl) N phenylamino~-3~ ethyl-2-methyl-3-indolYl)phthalide/ 3 ml, of 25~ aqueous sodium hydroxide and 50 ml. of hexamethylphosphoramide was stirred 1 hr. at room tem~erature and then treated with 3 ml of ethyl iodide.
After stirring at room temperature another 2 hrs. the reac-tion mixture was poured into water and the product extracted with toluene~ ~he toluene extracts were washed with water and saturated aqueous ~odium chloride, dried over anhydrous sodium sulfate and evaporated to dr~ness under vacuum. The residue was triturated with ligroin to give 0 2 g. of 5-~and . ' .

~V ~ ~ 7 V ~

6-)ethoxycarbonyl-3-[N-(4-ethoxyphenyll-N-phenylamino~-3-~l-ethyl-2-me~hyl-3-indolyl)phthalide as a light brown solid, m.p. 86-93C. (dec.~. A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

A mixture containing 5.5 g. of 5-~and 6-)carboxy-3-[N-~4-ethoxyphenyl)-N-phenylamino]-3- ~-ethyl-2-methyl-3-indolyl)phthalide, 8 ml. of n-octyl bromide, 6 g. of potassium carbonate and 150 ml. of acetone was heated under reflux overnight. The reaction mixture was then poured into 5%
aqueous ammonia and the product extracted with toluene. The toluene extracts were washed with water and saturated aqueous sodium chloride, dried over anhydrous sodium sulfate and evaporated to dryness under reduced pressure. Excess n-octyl bromide was removed from the residue by vacuum distillation leaving as an oil 5-(and 6-)n-octyloxycarbonyl-3-[N-~4-ethoxy-phenyl)-N-phenylamino~-3-ll-ethyl-2-methyl-3-indolyllphthal-ide, A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

To a mixture containing 3 . O g . of 5-~and 6-)carb-oxy-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3- ~-ethyl-2-methyl-3-indolyl)phthalide, 3.0 g. of potassium carbonate and 100 ml. of N,N-dimethylformamide was added 2.0 g. of ~-bromotolu-ene. After stirring 10 min. the reaction mixture was poured into ice-water and the resulting precipitate was collected and dissolved in acetone. The acetone solution was evap-orated to dryne~s and the residue was triturated with ligroin to give 5-(and 6-)benzyloxycarbonyl-3-~N-~4-ethoxyphenyl)-N-' ' ' . . .
. .:, ~ ' , ".' ' ' ~,,~ ~ ' ~ 7~

phenylamino~-3~ ethyl-2-methyl-3-indolyl~phthalide as a pale orange solid, m~p~ 80 85C. A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange-yellow colored image .
A mixture containing 4.5 g~ of 3,4,5,6-tetrachloro-2-(1-ethyl-2-methyl-3-indolylcarbonyl)benzoic acid, 1.0 ml.
of thionyl chloride and 200 ml. of 1,2-dichloroethane was heated up to the reflux temperature, then cooled to 30C.
and treated with a solution containing 2.1 g. of 4-ethoxy-N-phenylaniline in 20 ml. of 1,2-dichloroethane. After stirring overnight at room temperature the reaction mixture was poured into S~ aqueous ammonia and the product extracted with 1,2-dichloroethane. The organic extracts were washed with water and saturated aqueous sodium chloride and evaporated to dry-ness. The residue was triturated with cyclohexane to give 3.1 g. of 4,5,6,7-tetrachloro 3-[N-~4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide, m.p. 182-188~C. The infrared spectrum indicated this material to be contaminated with unreacted 3,4,5,6-tetrachloro-2-~1-ethyl-2-methyl-3-indolylcarbonyl)benzoic acid. Evaporating the triturant to dryness and triturating the residue successively from ligroin and acetone afforded 0.4 g. of the pure phthal-ide, m.p. 193-194C. (dec ) A toluene solution of the pro-duct contacted with acidic clay or phenolic resin developed an orange colored image.
EXAMP~E 9 A. Following a procedure similar to that described in Example lA but employing 3 1 g of 2-(1-ethyl-2-methyl-3-indolylcarbonyl)benzoic acid and 1 8 g. of diphenylamine .

.

7Sl~

there was obtained 0,78 g~ of 3~ ethyl-2-methyl-3-indolyl)-3-(diphenylamino)phthalide, m~p. 125-130C. ~dec.). A tolu-ene solution of the product contacted with acidic clay or phenolic resin developed a yellow colored image.
B. A mixture containing 3,0 g~ of N,N-diphenylphthal-amic acid, 1.6 g~ of 1-ethyl-2-methylindole, 7 ml. of acetic anhydride and 0,5 mlO of pyridine was stirred several hours at room temperature. The reaction mixture was filtered to remove unreacted N,N-diphenylphthalamic acid. The filtrat~
was analyzed by thin layer chromatography and shown to contain the desired 3-(1-ethyl-2-methyl-3-indolyl)-3-tdiphenylamino)-phthalide identical to the product of part A above contami-nated with some 3,3-bis-(1-ethyl-2-methyl-3-indolyllphthalide.
C. The reaction of part B above was carried out in the ab~ence of pyridineO The reaction mixture was poured into 5% aqueous ammonia and the product extracted with toluene.
The toluene extract~ were washed with water and saturated aqueou~ sodium chloride and evaporated to dryness. The residue was e~sentially identical to the product of part B above as indicated by thin layer chromatography.

~ . ..
A mixture containing 7.0 g. of 2- ~-ethyl-2-methyl-3-indolylcarbonyl)-4-~and 5-)nitrobenzoic acid, 4.4 g. of 4-ethoxy-N-phenylaniline, 10 mlO of acetic anhydr-ide and 2 ml. of pyridine was stirred 2 hrs. at roomtemperature. The reaction mixture was diluted with 10 ml.
of 2-propanol and 50 ml. of ligroin to precipitate 3.73 g.
of unreacted 2-(1-ethyl-2-methyl-3-indolylcarbonyl)-4-~and 5-)nitrobenzoic acid. The filtrate was poured into 5%
; 30 aqueous ammonia and the product extracted with toluene. The '' ' ~ ' ' L(l 1~7V~

toluene extracts were wa~hed with water and ~aturated aqueou~
sodium chloride and evaporated to dryness under vacuum. The resldue wa~ triturated successively with ligroin and 2-propanol to glve 1.4 g. of 3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3-indolyl)-5-(and 6-)nitrophthalide, m.p. 171-173C. A toluene solution of the product contacted with acidic clay or phenolic re~in developed an orange colored image.

To a stirred mixture containing 7.4 g. o~ phthalic anhydride and 16.0 g. of 1-butyl-2-methylindole at 0-5C. wa~
added portionwi~e 13.3 g. o~ alum~num chloride. The mixture was dlluted w~th 50 ml. o~ benzens and stirred overnight at room temporature. The reaction mixture wa~ poured into 200 ml. o~ 5~ hydrochloric acid and the product extracted with benzeno. The bonzone extract~ were shaken with dilute aqueous pota~lum hydroxiao. The aqueous alkaline layer was separated, cooled with loo and brought to p~ 4 with acetic acid. The pr~cipitatod product wa~ collectod and driod to give 2-(1-butyl-2-m~thyl-3-lndolylcarbonyl)~onsoic acid, m.p. 88-92C.
Thi~ intormodlat~ wa~ u~o~ ln tho praparation of th~ compound of Exampl~ 17.

Followlng a proo-dur~ ~imllar to that d~crlb~d ln Examplo 11 but mploying 7.4 g. of phthallc anhyarido and 16.0 g. of 1-n-octyl-2-mothylindols thoro wa~ obtainod 6.9 g. o~
2-~1-n-ootyl-2-mothyl-3-indolylcarbonyl)bonzoic acid, m.p.
121-123C. Thi~ intormediate W~B u~ed in the preparation o~
th~ co~pound o~ ExamplH 18.

`J 30 A mlxture contalning 5.0 g. of phthallc anhydrlde, :10~

5.0 g. of 2,5-dimethylindole and 30 ml. of 1,2-dichloroethane was heated under reflux for 20 hours. The reaction mixture was cooled and the resulting precipitate was collected, wash-ed with 1,2-dichloroethane and dried to give 3.8 g. of 2-(2,5-dimethyl-3-indolylcarbonyl)benzoic acid, m.p. 198-200C.
(dec.). This intermediate was used in the preparation of the compound of Example 19.

Following a procedure similar to that described in Example 13 but employing lO g. of phthalic anhydride and lO
g. of 5-methoxy-2-methylindole there was obtained 4.6 g. of 2-(5-methoxy-2-methyl-3-indolylcarbonyl)benzoic acid, m.p.
202-203C. ~dec). This intermediate was used in the prepara-tion of the compound of Example 20.

A. To a stirred mixture of 14.8 g. of phthalic -anhydride, 16.2 g. of N-methylpyrrole and 50 ml. of chloro-benzene at 0-5C. was added portionwise over 1.25 hrs. 39.0 g. of aluminum chloride. The temperature was maintained at 2-5C. throughout the addition. After diluting with an addi-tional 20 ml. of chlorobenzene the reaction mixture was allowed to stand over a weekend. Excess water was added and the mixture was stirred. The solids were allowed to settle and the supernatant water-chlorobenzene mix was de-canted. The residue was taken up in 50 ml. of 5~ aqueous sodium hydroxide. The resulting solution was filtered and the filtrate was acidified to pH 3 with dilute hydrochloric acid.
The precipitated yellow solid was collected and dried to give 9.46 g. of 2-(N-methyl-2-(and 3-)pyrrolylcarbonyl)benzoic , 30 acid, m.p. 165-167C.

-, ~ '70 ~

B. Followlng a procedure similar to that described in Example lA but employing 2.3 gO of 2-(N-methyl-2-(and 3-)-pyrrolylcarbonyl)benzoic acid and 2.2 g. of 4-ethoxy-N-phonyl-aniline there was obtained 1.6 g, of 3-~N-~4-ethoxyphenyl)-N-phenylamino]-3-(N-methyl-2-(and 3-)pyrrolyl)phthalide, m.p.
115-134C. A toluene solution of the product contacted with acidic clay or phenolic resin developed a yellow colored image.
EXAM~E 16 Following a procedure similar to that described in Example lA but employing 3.43 g. of 2-~9-ethyl-3-carbazolyl-carbonyl)benzoic acid and 2.13 gO of 4-ethoxy-N-phenylaniline there was obtained 0.73 g. of 3-[N-t4-ethoxyphenyl)-N-phenyl-amino]-3-(9-ethyl-3-carbazolyl~phthalide, m.p. 75-85C. tdec.).
A toluene solution of the product contacted with acidic clay or phenolic resin developed a yellow-orange colored image~
Following a procedure similar to that described in Example lA but employing the appropriate 2-~3-indolyl~benzoic acids of Formula II and substituted diphenylamines of Formula III, the following compounds of Formula I, Examplos 17-29, wherein n i8 0 and Z i8 were obtained: -ExAMæLE Rl/R2/ 3 l/ 2 3/ 4 mC P ~C ) .
17 n-C4Hg H H 54-92 HH3 H 4-C2H50 yellow-orange 18 n C8 17 H H ---3Q CH3 H 4-C2H50 yellow-orange ~ H -29--:

EXAMPLE Rl/R2/R3 Yl/Y2 Y3/Y4 m p (C ) -CH3 H 4-(CH3)2CHO yellow H H H 68-75 (dec.) CH3 H 4-C2H5O yellow-orange CH3 H 3-CH3 yellow H
22 H H H 66-75 ~dec.) HH3 H 4-C2H5O orange-yellow 23 H H H 103-125 tdec.) CH3 H 4-tCH3)2cHO yellow H

CH3 H 4-~CH3)2N brown H

CH3 H 2-COOCH3 pink H

CH3 4-(CH3)2N 4-(CH3)2N grape H

CH3 H 4-CH3CONH yellow H

CH3 C8 17 4-arylalkyl yellow CH3 C8 17 C8 17 yellow H

A solution containing 1.46 g. of the color former of Example lB in 60 ml. of isopropyl~iphenyl and a solution containing 5 g. of carboxymethylcellulose in 200 ml. of water .
:~ , - . : - . .
.
,.- ,~
' ,~ ' .

were mixed and emulslfied by rapid stirrlng. The desired particle size (S mlcron~) was checked by microscope. To the emulsion was added a solutlon containing 15 g. of pig-skin gelatin in 120 ml. of water. The pH was adjusted to 6.5 with 10~ aqueous sodlum hydroxide with rapid stirring, and following the gradual addition of 670 ml. of water at 50C.
the pH was adjusted to 4.5 with 10% aqueous acetic acid with continued rapid stirring. After 5 minutes the mixture was cooled to 15C~, treated with 10 g. of 25~ aqueous glutaralde-hyde and rapidly stirred for lS minutes. The resulting micro-capsule dispersion was stirred more slowly overnight, diluted with water to 1120 g. and coated on white typewriter paper sheets (0.0015 in. film thickness). The sheets were air dried. Duplicate typewritten images were made on receiving sheets coated with either phenolic resin or acidic clay. The color former of Example lB produced a yellow colored image on both types of receiving sheets.

Following a procedure similar to that described in Example 30 but substituting soy oil for isopropylbiphenyl, the color former of Example 6 was microencapsulated and coat-ed on a transfer sheet. The co~or former developed an orange colored image on both types of receiving sheets.

A polyvinyl alcohol dispersion of the color former of Example 7 was prepared by shaking 1 hour on a paint shaker a mixture containing 2.0 g. of the color former, 3.7 g. of water, 8.6 g. of 10% aqueous polyvinyl alcohol and 10 g. of zirconium grinding beads. A polyvinyl alcohol dispersion of Bisphenol A was prepared by shaking a mixture containing 9.8 g.

7V~3 of Bisphenol A, 18.~ g. of water, 42 g. of 10~ aqueous poly-vinyl alcohol and 70 ml. of zirconium grinding beads. The coating mixture was made by combining and thoroughly mixing 2.1 g. of the polyvinyl alcohol dispersion of the color former with 47.9 g. of the polyvinyl alcohol dispersion of Bisphenol A. The coating mixture was applied (at thicknesses of 0.003 in. and 0.0015 in.) to white mimeo paper sheets and the sheets were dried at room temperature. Contacting the coated sheets with a heated stylus at a temperature between 110C. and 150C. produced a dark orange image.

A mixture containing 5.4 g. of 2-[4-Idimethylamino)-benzoyl]benzoic acid, 3.4 g. of diphenylamine, 2 ml. of pyridine and 15 ml. of acetic anhydride was stirred at room temperature. After a few minutes the solid reactants were com-pletely dissolved and after 15 minutes an orange solid pre-cipitated. The reaction mixture was stirred an additional 15 minutes and then diluted with 20 ml. of 2-propanol and 50 ml.
of ligroin. After stirring an additional 10 minutes the solids were collected, washed with ligroin and 2-propanol (which re-moved an orange impurity) and dried to give 5.9 g. of 3-[4-(dimethylamino)phenyl]-3-diphenylaminophthalide as a cream solid, m.p. 188-190C. (dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

A mixture containing 5.4 g. of 2-~4-~dimethylamino)-benzoyl]benzoic acid, 4.3 g. of 4-ethoxy-N-phenylaniline, 0.5 g. of urea and 15 ml. of acetic anhydride was stirred 0.5 hr.
at room temperature. Complete dissolution of the solid re-: , . . .. .

~V~;Z70~
actants wa~ followed shortly by precipitation of the product.
After diluting the reaction mixture with 20 ml. of 2-propanol the product was collected, washed with 2-propanol and dried to give 8.4 g. of 3-[4-(dimethylamino)phenyl]-3-[N-(4-ethoxy-5 phenyl)-N-phenylamino]phthalide as a white solid, m.p. 214-216C. (dec.) A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange color-ed image.

A mixture containing 6.24 g. tO.02 mole) of 5-~di-methylamino)-2-[4-(dimethylamino~benzoyl]benzoic acid, 6.25 g. (0.03 mole) of 4-ethoxy-N-phenylaniline and 20 ml. of acetic anhydride was stirred at room temperature for 20 hours. The reaction mixture wa~ then diluted with 30 ml. of 2-propanol 15 and stirred an additional 0.5 hr. The solids were collected, washed with ligroin and dried to give 9.3 g. of 6-(dimethyl-amino)-3-[4-(dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide as a pale pink solid, m.p. 200-202C.
(dec.). A toluene solution of the product contacted with 20 acidic clay or phenolic resin developed an orange colored image, which, on acidic clay, became green after exposure to fluoroecent light.

A mixture containing 2.0 g. of 2-~2,4-bis-(dimeth-25 ylamino)henzoyl]benzoic acid, 1.4 g. of 4-ethoxy-N-phenyl-aniline, 1 ml. of pyridine and 8 ml. of acetic anhydride was stirred 1.5 hrs. at room temperature. Dilution with 20 ml.
of 2-propanol and 50 ml. of ligroin produced no precipitate.
The reaction mixture was therefore poured into 1096 aqueous 0 ammonia and the product was extracted with toluene. The .
' .

~ 7 ~ ~

org~nlc extract~ were washed with water and ~aturated aqueous sodium chloride and evaporated to dryness under vacuum. Tri-turation of the residue with ligroin afforded 2.18 g. of 3-[2,4-bis-(dimethylamino)phenyl~-3-[N-~4-ethoxyphenyl)-N-phen-ylamino]phthalide as a pale orange ~olid, m.p. 111-117C. (dec.).
A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.
ExAMæLE 37 A mixture containing 1.7 g. of 3,4,5,6-tetrachloro-2-[4-(dimethylamino)benzoyl~benzoic acid, 0.5 ml. of thionyl -chloride and 200 ml. of 1,2-dichloroethane was heated 0.5 hr. under reflux to produce a pale green solution. After cooling to 35C. a ~olution containing 1.0 g. of 4-ethoxy-N-phenyl-aniline and a few drops of pyridine in 10 ml. of 1,2-dichloroethane was added and stirring at room temperature was continued for 2 days. The reaction mixture was then pour-ed into 10~ aqueous ammonia and the product extracted with 1,2-dichloroethane. The organic extracts were washed with water and saturated aqueous sodium chloride and evaporated to dryness under vacuum. The residue was slurried in 100 ml. of acetone and a white water-soluble solid was filtered off.
The filtrate was evaporated to dryness and the residue was triturated with 2-propanol to give 1.5 g. of crude 4,5,6,7-tetrachloro-3-~4-(dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide as a gray solid, m.p. 112-121C. The nmr spectrum indicated the product to be a mixture containing the desired phthalide and unreacted 3,4,5,6-tetrachloro-2-~4-~dimethylamino)benzoyl]benzoic acid in an approximate ratio of 60:40. A toluene solution of the product contacted with acidic clay developed a brown colored image; and when con-. ~.
. ~ : ; ~ .

'7Vl~
tacted with phenolic resin produced a pinkish-purple colored image.

Following a procedure similar to that described in Example 33 but employing 3.21 g. of 2-(9-julolidinylcarbonyl)-benzoic acid and 2.13 g. of 4-ethoxy-N-phenylaniline there was obtained 4.61 g. of 3-(9-julolidinyl)-3-~N-(4-ethoxyphenyl)-N-phenylamino]phthalide, m.p. 143-147C. A toluene solution of the product contacted with acidic clay or phenolic resin .
developed a red colored image.

.
Following a procedure similar to that described in Example 36 but employing 1.0 g. of 2-~4-(dimethylamino)-benzoyl]benzoic acid and 1.4 g. of 4,4'-dioctyldiphenyl-amine there was obtained 0.62 g. of 3-14-~dimethylamino)phenyl~-3-[N,N-bis-(4-octylphenyl)amino]phthalide, m.p. 158-169C. A
toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image. In another preparation carried out in a manner similar to that described in Example 2 the product was obtained as a solid, m.p. 163-167C.
A 2 per cent (W/V) toluene solution of the product of this example was mixed in varying proportions with a 2 per cent (W/V) toluene solution of the known color former crystal violet lactone tCVL) and the resulting solution was contacted with phenolic resin with the following results.
Cpd of Ex. 38 CVL
(2~ solution) (2~ solution) color of image produced 7 0 ml. 3.0 ml. brownish violet black 306.5 ml. 3.5 ml. brownish violet black 6.0 ml. 4.0 ml. violet black 5.0 ml. 5.0 ml. bluish black 7V~ :

EX~PLE 40 __ _ A. Following a procedure similar to that described in Example 36 but employing 3.1 g. of 2-[4-(diethylamino)-2-meth-ylbenzoyl~benzoic acid and 3.0 g. of 4,4'-bis(dimethylamino)-diphenylamine there was obtained 2.55 g. of 3-[4-(diethylamino)-2-methylphenyl~-3-[N-(4-dimethylaminophenyl)-N-(4-dimethyl-aminophenyl)amino~phthalide, m.p. 67-83.5C. A toluene solu-tion of the product contacted with acidic clay or phenolic resin eveloped a black-colored image.
B. A mixture containing 6.2 g. of 2-~4-(diethylamino)-2-methylbenzoyl]benzoic acid and 5.1 g. of 4,4'-bis(dimethyl-amino)diphenylamine, 20 ml. of acetic anhydride and 2.0 g. of urea was stirred 2 hours at room temperature and then poured into 5% aqueous ammonium hydroxide and extracted with toluene The organic extracts were dried over anhydrous sodium sulfate and evaporated to dryness under vacuum. The residue was dis-solved in 200 ml. of DMF and slowly added to 1-1/2 liter of water containing 1 g of Dabco with vigorous stirring. The air dried product was weighed S.0 g. and was essentially identical to the product of part A above.
C. In a procedure similar to that descri~ed in Example 37, 1.7 g. of thionyl chloride was added to a mixture of 100 ml. of benzene and 50 ml. of 1,2-dichloroethane. After 4.7 g.
of 2-[4-(diethylamino-2-methylbenzoyl]benzoic acid was added, the reaction mixture was warmed to 60C. to obtain a clear solution. When the solution had cooled to 40C., a solution of 3.5 g. of 4,4'-bis(dimethylamino)diphenylamine and 1 ml.
of pyridine in 50 ml. 1,2-dichloroethane was added and the mix heated to 60C. for one hour, cooled and stirred overnight at 0 room temperature. The tary material which separated was - ... : . . . . . . . .

;. .: :
.

, ' ~.~ '' ' ' 7~
filtered, washed and dissolved in dimethylformamide. Addition to an excess of water yielded 4.2 g. o~ a light grape-colored solid which developed a bl2ck color on silica gel.

A. To a stirred mixture containing 36 g. of 4-(and 5-)-carboxy-2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid (pre-pared from trimellitic anhydride and 3-(diethylamino)phenol, 60 ml. of diethyl sulfate and 450 ml. of ace~tone at 35C. was added dropwise over 2 hours a solution containing 25 g. of potassium hydroxide in 75 ml. of water. When the addition was complete stirring was continued an additional 2 hours. Another 20 g. of potassium hydroxide in 60 ml. of water was added and the mixture was heated under reflux 1 hour. Solvent was then allowed to distill until the internal temperature reached 96C. The reaction mixture was maintained at 96C. 0.5 hour then stirred at room temperature overnight, diluted with 100 ml. of water and brought to pH 4.0 with 3N hydrochloric acid.
The resulting red precipitate was collected, washed with water and air-dried to give 37 g. of 4-~and 5-)carboxy-2-t4-diethyl-amino-2-ethoxybenzoyl)benzoic acid, m.p. 63-96C. which was used without further purification.
B. A mixture containing 8.0 g. of 4-(and 5-)carboxy-2-(4-diethylamino-2-ethoxybenzoyl)benzoic acid, 8.0 g. of 4-di-methylamino-4'-diethylaminodiphenylamine, 25 ml. of acetic anhydride and 2 ml. of pyridine was stirred 2 hours at room temperature. The mixture was poured into toluene and the product extracted with 10~ aqueous ammonia. The aqueous alkaline extracts were acidified to pH 5 with 3N hydrochloric acid. The resulting precipitate was collected, washed with water and dried to give 4.8 g. of 5-(and 6-)carboxy-3-[4-(di-:, ' ' , ' '.:' .
.

~ 7 ~ 8 ethylamino)-2-ethoxyphenyl]-3-~N-(4-dimethylaminophenyl)-N-(4-diethylaminophenyl)amino]phthalide, m.p. 167-173C.
C. To a mixture contalning 4.0 g. of the above acid, 4.0 g. of potassium carbonate and 100 ml. of N,N-dimethyl-formamide was added 4.0 g. of dimethyl sulfate. After stirringfor one hour, the reaction mixture was poured into 1 liter of water containing 10 ml. of concentrated ammonium hydroxide.
The resulting precipitate was collected, washed with water and dried to give 0.2 g. of 5-(and 6-)methoxycarbonyl-3-[4-~diethylamino)-2-ethoxyphenyl]-3-[N-(4-dimethylaminophenyl)-N-(4-diethylaminophenyl)amino]phthalide, m.p. 87-93C. A
toluene 401ution of the product contacted with acidic clay or phenolic resin developed a brown-black-colored image.
Following procedures similar to those of Examples 33 to 36 but employing the appropriate 2-[(4-disubstituted-amino)benzoyl]benzoic acids of Formula II and the appropriate-ly substituted diphenylamine of Formula III the phthalides of Formula I wherein Z is R8RgN
Examples 42 to 78, were obtained.

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The color formers of Examples 34 and 42 were micro-encapsulated as follows. A solution containing 1 g. of the color former in 49 g. of isopropylbiphenyl and a solution con-taining 5 g. of carboxymethylcellulose in 200 ml. of water were mixed and emulsified by rapid stirring. The desired particle size (5 microns) was checked by micro~cope. To the emulsion was added a solution containing 15 g. of pigskin gelatin in 120 ml. of water. The pH was adjusted to 6.5 with 10~ aqueous sodium hydroxide with rapid stirring, and follow-ing the gradual addition of 670 ml. of water with heating (at 50C.) the pH was adjusted to 4.5 with 10% aqueous acetic acid with continued rapid stirring. After 5 minutes 10 g. of 25~ aqueous glutaraldehyde was added and rapid stirring was continued an additional 15 minutes. The resulting microcapsule dispersion was stirred more slowly overnight.
Starch (12 g.) was gradually added to 60 ml. of water. The mixture was heated to 90C. and stirrçd 15 minutes.
After cooling to room temperature the mixture was added to 473 g. of the abova microcapsule dispersion and the resulting emulsion stirred vigorously for 2 minutes, and then coated on white typewritsr paper sheets (0.0015 in. film thickness).
The sheets were air dried. Duplicate typewritten images were made on receiving sheets coated with either phenolic resin or acidic clay. The color former of Example 34 produced an orange image on both types of receiving sheets, and the color former of Example 42 produced a red image on both types of receiving sheets.

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~ '7~ 8 of Examples 34, 35 and 42 were prepared by shaking 1 hour on a paint shaker a mixture containing 2.0 g. o the color former, 3.7 g. of water, 8.6 g. of 10% aqueous polyvinyl alcohol and 10 g. of zirconium grinding beads. A polyvinyl alcohol dis-persion of Bisphenol A was prepared by shaking a mixture con-taining 9.8 g. of Bisphenol A, 18.2 g. of water, 42 g. of 10% aqueous polyvinyl alcohol and 70 ml. of zirconium grinding beads. The coating mixture was made by combining and thoroughly mixing 2.1 g. of the polyvinyl alcohol dispersion of the color former with 47.9 g. of the polyvinyl alcohol dis-persion of Bisphenol A. The coating mixture was applied (at thicknesses of 0.003 in. and 0.0015 in.) to white mimeo paper qheets and the sheets were dried at room temperature. Con-tacting the coated sheets with a heated stylus at a tempera- .
ture between 110C. and 150C. produced a dark orange image on the sheet coated with the color former of Example 34, a ~;
dark red image on the sheet coated with the color former of Example 35 and a dark purple image on the sheet coated with the color former of Example 42.

Following a procedure similar to that described in Example 79 but substituting kerosene for isopropylbiphenyl the color former of Example 66 was microencapsulated and coat-ed on a transfer sheet. The color former developed a red image on both type~ of receiving sheets.

Following a procedure similar to that described in Example 79 but omitting the addition of starch to the micro-capsule dispersion, the color former of Example 40 was micro-encapsulated and coated on a tran~fer sheet. The color former ... ~ . .
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The image formPd on the clay-coated receiving sheet turned green on standing.

Following a procedure similar to that described in Example 79 but omitting the addition of starch to the micro-capsule dispersion, a mixture containing 0.876 g. of the color former of Example 39 and 0.584 g. of crystal violet lactone was microencapsulated and coated on a transfer sheet.
~he mixture of color formers developed a blue to black image on resin-coated receiving sheets.
It is contemplated that by following procedures similar to tho~e described in the foregoing Examples but employing the appropriate 2-(3-indolyl) or [(4-disubstituted-amino)benzoyl]benzoic acids of Formula II and appropriately substituted diphenylamines of Formula III the phthalides of Formula I wherein Z is ~' Examples 84-117, or wherein Z is ~ .
R8RgN ~ R7 Examples 118-149, will be obtained.

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Claims (42)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A compound having the Formula I

...I

wherein:
Q is di-lower-alkylamino, nitro, halo or COX, where X is hydroxyl, benzyloxy, alkoxy having from 1 to 18 carbon atoms or OM where M is an alkali metal cation, an ammonium cation or a mono-, di- or tri-alkylammonium cation having from 1 to 18 carbon atoms;
n is 0; or 1 when Q is di-lower-alkylamino, nitro or COX: or from 1 to 4 when Q is halo;
Y1, Y2, Y3 and Y4 are the same or different and are hydrogen, halo, hydroxyl, lower-alkoxy, alkyl having from 1 to 9 carbon atoms, phenyl-lower-alkyl, COOR4 or NR5R6, where R4 and R5 are hydrogen or lower-alkyl and R6 is hydrogen, lower-alkyl, cycloalkyl having from 5 to 7 carbon atoms, or lower alkanoyl;
Z is ; ; or 9-julolidinyl in which:
R is hydrogen or non-tertiary alkyl having from 1 to 4 carbon atoms;
R1 is hydrogen, or non-tertiary alkyl having from 7 to 18 carbon atoms;
R2 is hydrogen, phenyl or non-tertiary alkyl having from 1 to 4 carbon atoms;
R3 is hydrogen, non-tertiary alkyl having from 1 to 4 carbon atoms or non-tertiary alkoxy having from 1 to 4 carbon atoms;
R7 is hydrogen, halo, lower-alkyl, lower-alkoxy or di-lower-alkylamino;
R8 is lower-alkyl; and R9 is lower-alkyl, benzyl, phenyl or phenyl sub-stituted with a lower-alkyl or lower-alkoxy group.

2. A compound according to claim 1, wherein R3 is hydrogen; R7 is hydrogen or lower-alkyl; and R9 is lower-alkyl or benzyl.

3. 3-[N,N-Bis-(3-ethyl-5-nonylphenyl)amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

4. A compound according to claim 2, wherein Y1 and Y3 are each hydrogen.

5. A compound according to claim 4, wherein Y2 and Y4 are the same or different and are hydrogen, lower-alkoxy, alkyl having from 1 to 9 carbon atoms or NR5R6 where R5 and R6 are each lower-alkyl.

6. A compound according to claim 5, wherein n is 0.

7. 3-[N-(4-Ethoxyphenyl)-N-phenylamino-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

8. 3-(N,N-Diphenylamino)-3-(1-ethyl-2-methyl-3-indolyl)-phthalide.

9. 3- [N-(3-methylphenyl)-N-phenylamino]-3-(1-6th 2-methyl-3-indolyl)phthalide.

10. 3-(1-Ethyl-2-methy1-3-indolyl)-3-(N,N-bis-(4-octyl-phenyl)amino]phthalide.

11. 3-[4-(Dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide.

12. 3-[4-(Dimethylamino)phenyl]3-[N-(4-isopropoxyphenyl)-N-phenylamino]phthalide.

13. 3-[4-(Diethylamino)-2-methylphenyl]-3-[N-(4-ethoxy-phenyl)-N-phenylamino]phthalide.

14. 3-[4-(Dimethylamino)phenyl]-3-[N,N-bis-(4-octylphenyl)-amino]phthalide.

15. 3-[4-(Dimethylamino)phenyl]-3-(N,N-diphenylamino)-phthalide.

16. 3-[4-(Ethylbenzylamino)phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide.

17. 3-[4-(Diethylamino)-2-methylphenyl]-3-{N,N-bis[4-(di-methylamino)phenyl]amino}phthalide.

18. A compound according to claim 5, wherein n is 1 and Q
is di-lower-alkylamino.

19. 6-(Dimethylamino)-3-[4-(dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide.

20. 6-(Dimethylamino-3-[4-(dimethylamino)phenyl]-3-[N,N-bis(4-octylphenyl)amino]phthalide.

21. A compound according to claim 9, wherein Q is halo and n is 1 to 4.

22. 4,5,6,7-Tetrachloro-3-(1-ethyl-2-methyl-3-indolyl)-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide.

23. 4,5,6,7-Tetrachloro-3-(4-(dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl)-N-phenylamino]phthalide.

24. A compound according to claim 5, wherein n is 1 and Q
is COX and X is hydroxyl, benzyloxy, alkoxy having from 1 to 18 carbon atoms or OM where M is an alkali metal cation, an ammonium cation or a mono-, di- or tri-alkylammonium cation having from 1 to 18 carbon atoms.

25. 5-Carboxy-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

26. 6-Carboxy-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

27. A compound according to claim 24, wherein X is OM
and M is an alkali metal cation, an ammonium cation or a mono-, di- or tri-alkylammonium cation having from 1 to 18 carbon atoms.

23. Tert-octylammonium 3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide-5-carboxylate.

29. Tert-octylammonium 3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide-6-carboxylate.

30. 5-(Methoxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

31. 6-(Methoxycarbonyl)-3-1N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

32. 5-(Ethoxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

33. 6-(Ethoxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

34. 5-(Octyloxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

35. 6-(Octyloxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

36. 5-(Benzyloxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

37. 6-(Benzyloxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenyl-amino]-3-(1-ethyl-2-methyl-3-indolyl)phthalide.

38. A process for preparing a compound according to claim 1 , which comprises preparing a compound wherein Q is limited to di-lower-alkylamino, nitro, halo and COX where X is hydroxyl, benzyloxy or alkoxy having from 1 to 18 carbon atoms by:
a. reacting a 2-substituted benzoic acid having the Formula II (herein) with a diarylamine having the Formula III (herein) in the presence of the anhydride of an alkanoic acid having from 2 to 5 carbon atoms and an organic base;
b. reacting a 2-substituted benzoic acid having the Formula II (herein) with thionyl chloride, phosphorus oxy-chloride, phosphorus trichloride or phosphorus penta-chloride; and reacting the resulting product wih a diaryl-amine having the Formula III (herein) in the presence of an organic base; or c. in the case that Z is , reacting a phthalamic acid having the Formula IV (herein) with an indole having the Formula V (herein), and, if it is desired to obtain a compound where Q is COX where X is benzyloxy, alkoxy or OM where M is an alkali metal cation, an ammonium cation or a mono-, di- or tri-alkylammonium cation having from 1 to 18 carbon atoms, converting a compound obtained wherein Q is COOH to said corresponding compound.

39. A pressure-sensitive carbonless duplicating system or thermal marking system characterized by containing a color-forming substance comprising a compound according to claim 1.

40. A pressure-sensitive carbonless duplicating system according to claim 39, characterized by a support sheet coated on one side with a layer of pressure-rupturable microcapsules con-taining a liquid solution of the color-forming substance.

41. A thermal marking system according to claim 39, characterized by a support sheet coated on one side with a layer containing a mixture of the color-forming substance and an acidic developer arranged such that application of heat will produce a mark-forming reaction between the color-forming substance and the acidic developer.

42. A hectographic copying system comprising a support sheet coated on one side with a layer containing a color-forming substance comprising a compound according to claim 27.