GB1564559A - 3(diphenylamino) phthalides - Google Patents

Abstract

New 3-[4-(disubstituted amino)phenyl]- or 3-[(9-julolidinyl)]-3-(diphenylamino)phthalides of formula <IMAGE> in which the symbols are defined in Claim 1, are prepared by reacting benzoic acids substituted by (Q)n and, in position 2, by -COZ, with the corresponding diarylamine, in the presence of a C2-C5 alkanoic acid, a base, or else with the diarylamine in the presence of a base after conversion into cyclic lactone chloride. If desired, certain salts of the compounds in which (Q)n = COOH are prepared. The compounds obtained can be employed as colour-forming agents in pressure-sensitive systems and thermal marking systems.

Description

(54) 3-(DIPHENYLAMINO) PHTHALIDES (71) We, STIRLING DRUG INC., a Corporation organized and existing under the laws of the State of Delaware, United States of America, of 90 Park Avenue, New York, State of New York, United States of America, dd hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to 3-substituted-3-(diphenylamino)phthalides useful as color formers in pressure-sensitive carbonless duplicating systems, thermal marking systems and hectographic or spirit-reproducing copying systems; to processes for the preparation thereof; and to pressure-sensitive duplicating systems, thermal marking systems and hectographic copying systems containing the same.

Several classes of organic compounds of widely diverse structural types are known to be useful as color formers for carbonless duplicating systems. Among the more widely recognized classes, there may be named phenothiazines, for example, benzoyl leuco methylene blue; fluorans, for example, 2'-anilino-6' diethylaminofluoran; phthalides, the class with which this invention is concerned, for example, crystal violet lactone; and various other types of color formers currently employed in commercially accepted carbonless duplicating systems.

Typical of the many such systems taught in the prior art are those described in U.S.

Patents 2,712,507, 2,800,457 and 3,041,289.

Many of the color formers in the prior art suffer one or more disadvantages such as low tinctorial strength, poor light stability, low resistance to sublimation and low stability in common organic solvents, the latter disadvantage thus requiring the use of specialized and expensive solvents in order to maintain microencapsulated solutions of sufficient concentration for use in pressuresensitive copying systems. Other prior art includes U.S. Patents 3,736,168 and 3,491,112 and Japanese Patent Publication No. 71/4616.

R. Valters and V. Tsiekure in Khim. Geterotsikl. Soedin. 1975, (11)1476-8 discuss ring-chain tautomerism in 3-(N,N-diphenylamino)-3-phenylphthalide but disclose no utility for the compound.

This invention relates to compounds having Formula I

Formula 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 I 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 orNR5R6, where R4 and R5 are hydrogen or lower-alkyl and R6 is hydrogen, loweralkyl, cycloalkyl having from 5 to 7 carbon atoms, or lower alkanoyl; Z is

and 9julolidinyl 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 I 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 nontertiary 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 substituted with a lower-alkyl or lower-alkoxy group.

The compounds are useful as color formers in pressure-sensitive carbonless duplicating systems, thermal marking systems and hectographic copying systems.

Particularly embodiments relate to compounds having Formula I wherein Q, n, Y1, Y2, Y3 and Y4 have the previously given meanings and Z is

R1, R2, R3, R7, R8 and R9 having the previously given meanings. Preferred compounds within the ambit of this particular embodiment are those wherein: a) n is 0; 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 - phenyl aminol - 3 - (1 - ethyl - 2 - methyl - 3 - indolyl)phthalide, 3 - (N,Ndiphenylamino) 3 - (1 - ethyl - 2 - methyl - 3 - indolyl)phthalide, 3 - (1 - ethyl - 2 - methyl - 3indolyl) - 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 - phenylaminol - 3 - (I - ethyl - 2 - methyl - 3 - indolyl) - phthalide, 3 - [N - (4 - ethoxyphenyl) - N - phenylaminol - 3 - (1 - ethyl - 2 - methyl - 3 - indolyl) - 5 - (and 6-)methoxycarbonylphthalide, 5 - (and 6 - ethoxycarbonyl - 3 - [N - (4 - ethoxyphenyl) - N - phenylaminol - 3 - (1 - 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 - (1 - ethyl - 2 - methyl - 3indolyl)phthalide, 4,5,6,7 - tetrachloro - 3 - [N - (4 - ethoxyphenyl) - N - phenyl amino - 3 - (ethyl - 2 - methyl - 3 - indolyl)phthalide, 3 - (1 - ethyl - 2 - methyl- 3 - indolyl) - 3 - [N,N - bis - (4 - octylphenyl)amino]phthalide, 3 - [4 - (dimethylamino)phenyl] - 3 - [N - (4 - ethoxyphenyl) - N - phenylamino] - phthalide; 3 - [4 - (dimethylamino)phenyl] - 3 - [N - (4 - isopropoxyphenyl) - N - phenyl aminolphthalide; 4,5,6,7 - tetrachloro - 3 - [4 - (dimethylamino)phenyl] -3 [N - (4 - ethoxyphenyl) - N - phenylamino]phthalide; 3 - [4 - (diethylamino) 2 -- methylphenyl] - 3 - [(N - 4 - ethoxyphenyl) - N - phenylaminojphthalide; 3 [4 - (dimethylamino)phenyl] - 3 - [N,N - bis - (4 - octylphenyl)amino]phthalide; 6 (dimethylamino) - 3 - [4 - (dimethylamino)phenyl] - 3 - [N - (4 - ethoxyphenyl) N - phenylaminoiphthalide; 3 - [4 - (dimethylamino) - phenyl] - 3 - (N,N - diphenylamino)phthalide; 6 - (dimethylamino) - 3 - [4 - (dimethylamino)pheny1]- 3 - [N,N - bis(4 - octylphenyl)aminoiphthalide; 3 - [4 - (ethylbenzylamino) phenyl] - 3 - [N - (4 - ethoxyphenyl) - N - phenylamino]phthalide and 3 - [4 (diethylamino) - 2 - methylphenyl] - 3 - fN,N - bis[4 - dimethylamino)phenyl]amino - phthalide.

One can prepare the compounds of Formula I, by a process which comprises reacting a 2-substituted benzoic acid having Formula II

Formula II with a diarylamine having Formula III

Formula III in the presence of the anhydride of an alkanoic acid having from 2 to 5 carbon atoms, and an organic base; where in Formulas II and III, Z, n, Y1, Y2, Y3, and Y4 have the previously given meanings and Q is di-lower-alkyl-amino, nitro, halo and COX' where X' is hydroxy, bezyloxy or alkoxy having from 1 to 18 carbon atoms.

Another process for producing the compounds of Formula I, comprises reacting a 2-substituted benzoic acid of Formula II, with an inorganic acid chloride which is thionyl chloride, phosphorus oxychloride, phosphorus trichloride 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, Q, n, Y1, 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

comprises reacting a phthalamic acid having the Formula IV

Formula IV 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 n, Y1,Y2,Y3, Y4, R1, R2 and R3 have the above given meanings and Q is di- lower-alkylamino, nitro, halo or COX' where X' is as defined above.

The present invention also deals with a pressure-sensitive carbonless duplicating system, thermal marking system or hectographic copying system containing a color-forming substance comprising a compound having Formula I. A particular embodiment 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 responsive 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 application of heat will produce a mark-forming reaction between the color-forming compound and the acidic developer.

A further particular embodiment resides in a hectographic or spirit reproducing copying system comprising a transfer sheet coated on one side with a layer containing a color-forming substance comprising at least one compound having Formula I, wherein n is I and Q is COX where X is OM and M has the previously given meanings.

As used herein the term "halo" includes chloro, fluoro, bromo and iodo.

Chloro is the preferred halo substituent because of the relatively low cost and ease of preparation of the required chloro-substituted intermediates and because the other halogens offer no particular advantages over chloro. However the other above-named halo substituents are also satisfactory.

The terms "lower-alkyl, lower-alkoxy and di-lower-alkylamino" denote saturated, acyclic groups having from 1 to 4 carbon atoms which may be straight or branched as exemplified by methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, isobutoxy, tert-butoxy, dimethylamino, diethylamino, ethylmethylamino, dipropylamino, dibutylamino, isobutylmethylamino or di-tert-butylamino.

As used herein the term "cycloalkyl having from 5 to 7 carbon atoms" includes cyclopentyl, cyclohexyl and cycloheptyl.

The term "lower alkanoyl" denotes saturated acyclic acyl groups having from 1 to 5 carbon atoms which may be straight or branched as exemplified by formyl, acetyl, propionyl, butyryl, isobutyryl, valery, 2-methylbutyryl, isovaleryl or pivalyl.

The term "phenyl-lower-alkyl" includes benzyl, 2-phenylethyl, 2phenylpropyl, 3-phenylpropyl, 1-phenyl-butyl and 2,2-dimethyl-2-phenylethyl. If desired the phenyl group may contain a lower alkyl or lower alkoxy substituent.

The term "alkoxy having from 1 to 18 carbon atoms" includes, in addition to the above-noted lower-alkoxy groups, saturated, acyclic, straight or branchedchain groups such as n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-undecyloxy, n-dodecyloxy, n-tridecyloxy, n-tetradecyloxy, npentadecyloxy, n-hexahecyloxy, n-heptadecyloxy, n-octadecyloxy, 1methylpentyloxy, 2,2-dimethylbutyloxy, 2-methylhexyloxy, 1,4-dimethylpentyloxy, 3-ethylpentyloxy, 2-methylheptyloxy, I-ethylhexyloxy, 2-propylpentyloxy, 2methyl-3-ethylpentyloxy, 1,3 5-trimethylhexyloxy, 1 ,5-dimethyl-4-ethylhexyloxy, 5methyl-2-butylhexyloxy-2-propylnonyloxy, 2-butyloctyloxy, 1,1 - dimethylundecyloxy, 2-pentylnonyloxy, 1 ,2-dimethyltetradecyloxy and 1,1 - dimethyl-pentadecyloxy.

As used herein the term "alkyl having from 1 to 9 carbon atoms" denotes saturated monovalent straight or branched chain aliphatic hydrocarbon radicals including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, amyl, 1methylbutyl, 3-methylbutyl, hexyl, isohexyl, heptyl, isoheptyl, octyl, isooctyl, 2ethylhexyl, nonyl and 3-ethyl-heptyl.

The term "non-tertiary alkyl having from 1 to 18 carbon atoms" includes, in addition to the above-named alkyl groups having from 1 to 9 carbon atoms, excluding of course any tertiary alkyl groups, saturated, monovalent, straight or branched-chain aliphatic hydrocarbon radicals such as n-decyl, n-undecyl, ndodecyl, 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-hexyl, 2-propylnonyl, 2-butyloctyl, 2-pentylnonyl and 1,2-dimethyl-tetradecyl.

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 groups as above described. The alkyl groups can be the same or different provided the ammonium cation contains no more than 18 carbon atoms. As examples there can be named methyl-ammonium, tbutylammonium, t-octylammonium, n-dodecylammonium, n-octadecylammonium, di-n-butylammonium, di-n-nonylammonium, isopropyl-n-butyl-ammonium, dimethyl-n-butylammonium, tri-ethylammonium, N-ethyl-N,Ndiisopropylammonium, tributylammonium and di-n-butyl-octylammonium.

The term "9-julolidinyl" of course refers to the radical having the formula

Anhydrides of alkanoic acids of two to five carbon atoms incude acetic an hydride, propionic anhydride, butyric anhydride, isobutyric anhydride, valeric anhydride, isovaleric anhydride, a-methylbutyric anhydride and pivalic anhydride.

Acetic anhydride is preferred because of its low cost and high reactivity, however the other above-named anhydrides are also satisfactory.

Organic bases include pyridine, collidine, tri-lower-alkyl amines, urea and diarylamines of Formula IV hereinabove. Because of their low cost and ready availability pyridine 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 anhydride 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 0 to 1000 C. for from 10 minutes to 24 hours. The reaction is usually carried out in the absence of an inert diluent at 20 to 40"C. for 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 loweralkanol or low molecular weight hydrocarbon for example isopropyl alcohol or hexane or a mixture of these in order to effect precipitation of the product.

Alternatively, the reaction mixture can be poured into aqueous base such as dilute ammonium hydroxide, sodium hydroxide, sodium carbonate or sodium bicarbonate and the product extracted with an organic solvent such as benzene or toluene followed by evaporation of the organic solvent leaving the product as a residue. The product once isolated can be purified by conventional means such as trituration or recrystallization from a suitable solvent.

In accordance with a second process the compounds of Formula I, can be prepared in two steps which comprise first reacting 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 1,2dichloroethane, at 20 to 800 C. for 0.5 to 2 hours; and following removal of excess inorganic acid chloride, reaction of the resulting product which while not having been isolated is presumed to be a halide having Formula VI

Formula VI in which Q, 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 previously described at a temperature in the range of0 to 800C. for I to 48 hours. The product can be isolated and purified in the manner previously described.

In accordance with a further process the compounds having Formula I, wherein Z is

can be prepared by reacting a phthalamic acid of Formula IV with an indole of Formula V in the anhydride of an alkanoic acid having from two to five carbon atoms, such as acetic anhydride, with 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 100"C. for from 1 to 24 hours. The reaction is usually carried out at 20 to 40"C. for 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 not hydroxyl, it is ordinarily preferred to first prepare the compound of Formula I, wherein Q is COOH and then to subject this compound to the action of an esterifying agent, thereby converting it to the corresponding compound wherein Q is COX", where X" is benzyloxy or alkoxy, or to subject it to the action of a salifying agent, thereby converting it to the corresponding compound wherein Q is COOM wherein M is an alkali metal cation, an ammonium cation or a mono-, dior tri-alkyl-ammonium cation having 1 to 18 carbon atoms.

Some of the 2-substituted benzoic acids of Formula II required as starting materials in the preparation of 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.

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,

Formula VIII Formula IX Formula X Q and n in Formula VII having the meanings given above in Formula II and R, R7, R8 and R9 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-dichlorobenzene at a temperature of 0 to 100"C. The reaction is conveniently carried out in benzene in the presence of aluminum chloride at 0 to 250 C. 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 80 to 150"C.

It will, of course, be appreciated that reaction of an unsymmetrically substituted phthalic anhydride (Formula VII) with an indole, pyrrole, carbazole, aniline (Formula V, VIII, IX or X) orjulolidine can produce isomers or a mixture of isomers of 2-Z-CO-benzoic acids (Formula II). For example, reaction of a 3substituted phthalic anhydride (Formula VII where n is 1 and Q occupies position 3) with an indole, pyrrole, carbazole, aniline orjulolidine can produce either a 3- or 6-substituted 2-Z-CO-benzoic acid (Formula II where n is 1 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 1 and Q occupies position 4) can produce either a 4- or a 5-substituted 2-Z-CO-benzoic acid (Formula II, where n is 1 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 chromatography. Alternatively, the isomeric mixtures can be reacted directly with appropriate diarylamines of Formula III to produce isomeric mixtures of phthalides of Formula I. Thus reaction of a mixture of 3- and 6substituted 2-Z-CO-benzoic acids (Formula II where n is 1 and Q occupies position 3 or 6) with a diarylamine of Formula III will produce a mixture of 4- and 7substituted phthalides (Formula I where n is 1 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 occupies position 4 or 5) will produce a mixture of 5- and 6substituted phthalides (Formula I where n is I 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 this invention.

The diarylamines of Formula III which are also required as starting materials in the processes of the invention belong to a well known class of compounds and are either commercially available or readily obtained by conventional 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 possessing excellent light stability, resistance to sublimation and xerographic copiability. The compounds are thus highly suitable for use as colorless precursors, that is color-forming substances in pressure-sensitive carbonless duplicating systems. The compounds which produce a yellow to red color can be used as toners in admixture with other color formers to produce image of a neutral shade which desirably are readily copiable by xerographic means. The compounds of Formula I wherein at least one of Y, and Y2 and at least one of Y3 and Y4 are simultaneously di-lower-alkylamino 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 particular 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 Y1, Y2, Y3 and Y4 are alkyl of I to 9 carbon atoms, having enhanced solubility; in common and inexpensive organic solvents such as odorless mineral spirits, kerosene or vegetable oils 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 need for more expensive, specialized solvents such as polyhalogenated or alkylated 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.S. Patent 3,649,649. 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, for example, silton clay or a phenolic resin. Application of pressure to the manifold such as that exerted by a stylus, typewriter or other form or writing or printing causes the capsules on the reverse side to rupture. The solution of the color former released from 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 utilized. For example, the receiving sheet in a manifold can alternatively be coated with the subject compounds and the acidic developing agent can be contained in microcapsules applied to the reverse side of the top sheet 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 type, 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 Formula I 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 loweralkanols may be incorporated in any of the commercial hectographic or spiritreproducing 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 Formula 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 together. The master paper is then brought into contact with a succession of sheets of paper moistened with a suitable spirit-reproducing 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.

Example I.

A. A mixture containing 24 g. of 2-(1-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 I hr. at room temperature. Dilution with 30 ml. of 2-propanol and 100 ml. of ligroin produced no precipitate. The reaction mixture was therefore poured into 10% aqueous 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-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2- methyl-3-indolyl)phthalide, m.p. lie-135"C. Recrystallization 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 image.

B. A mixture containing 7.86 g. (0.02 mole) of 2-(l-ethyl-2-methyl-3- indolylcarbonyl)benzoic acid, 6.38 g. (0.03 mole) of 4-ethoxy-N-phenylaniline and 12 ml. of acetic anhydride was stirred overnight at room temperature and then poured into 200 ml. of 10 % aqueous sodium hydroxide and 100 ml. of toluene.

After stirring 1 hr. the layers were separated. The toluene layer was dried over anhydrous sodium sulfate, treated with decolorizing carbon and filtered. The filtrate was concentrated to 50 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.

Example 2.

A. A mixture containing 3.1 g. of 2-(1-ethyl-2-methyl-3-indolylcarbonyl)benzoic acid, 5 g. of 3,3'-diethyl-5,5'-di-nonyldiphenylamine, 10 ml. of acetic anhydride and I ml. 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-1-3-(1-ethyl-2-methyl-3- indolyl)phthalide, m.p. 76--90"C. (dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed a red colored image.

B. A mixture containing 6.2 g. of 2-(1-ethyl-2-methyl-3-indolylcarbonyl)benzoic acid, 9.3 g. of 3,3'-diethyl-5,5'-di-nonyldiphenylamine, 25 ml. of acetic anhydride and 1 g. of urea was stirred 2 hrs. 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 triturated with cyclohexane to give 4.96 g. of product essentially identical to the product of part A above.

Example 3.

A. A stirred solution containing 48.0 g. (0.250 mole) of trimellitic anhydride and 45.0 g (0.314 mole) of 1-ethyl-2-methylindole in 350 ml. of 1,2-dichloroethane was heated 2 hrs. under reflux. The reaction mixture was allowed to cool at room temperature and the precipitated solid was collected, washed with 1,2dichloroethane and dried to give 66.0 g. of a mixture of 4- and 5-carboxy-2-(l-ethyl 2-methyl-3-indolyl-carbonyl)benzoic acid, m.p. 198-20l0C. This material was used in subsequent reactions without further purification.

B. A mixture containing 7.0 g. of 4- (and 5-) carboxy-2-(l-ethyl-2-methyl-3- indolylcarbonyl)benzoic acid, 4.3 g. of 4-ethoxy-N-phenylaniline, 25 ml. of acetic anhydride and 2 ml. of pyridine was stirred 2 hrs. at room temperature. Dilution with 20 ml. of 2-propanol and 100 ml. of ligroin produced no precipitate. The mixture was therefore poured into toluene and the product extracted with 5% aqueous ammonia. The aqueous alkaline extracts were neutralized with 3N hydrochloric acid. The resulting precipitate was collected, washed with water and dried to give 5.6 g. of 5-(and 6-)carboxy-3-[N-(4-ethoxyphenyl)-N-phenylaminol-3 (1 -ethyl-2-methyl-3-indolyl)phthalide, m.p. 145--1480C.

C. To a stirred solution containing 2 g. of the above acid in 30 ml. of acetone was added 2 ml. t-octylamine. After stirring 10 minutes the mixture was diluted with 200 ml. of hexane. The solvents were decanted and the residue was triturated with hexane to give 1.8 g. of t-octylammonium 3-[N-(4-ethoxyphenyl)-N-phenylamno]- 3-(1-ethyl-2-methyl-3-indolyl)-phthalide-5-(and 6-)carboxylate, m.p. 1410 C. (dec.).

Example 4.

To a refluxing mixture containing 5.5 g. of 5-(and 6-)carboxy-3-[N-(4 ethoxyphenyl)-N-phenylamino]-3-( 1 -ethyl-2-methyl-3-indolyl)phthalide, 3 g. of potassium carbonate and 150 ml. of acetone was added 4 g. of dimethylsulfate.

After heating 1 hr. under reflux the mixture was poured into 300 ml. of 5 % aqueous ammonia and extracted with 400 ml. of toluene. The toluene extracts were washed with water and saturated aqueous sodium chloride and evaporated to dryness.

Trituration of the residue with ligroin afforded 0.6 g. of 5-(and 6-)methoxycarbonyl 3-[N-(4ethoxy-phenyl)-N-phenylamino]-3-( 1 -ethyl-2-methyl-3-indolyl)phthalide as a tan solid, m.p. 79-840C. (dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed a yellow-orange colored image.

Example 5.

A mixture containing 3.0 g. of 5-(and 6-)carboxy-3-[N-(4-ethoxyphenyl)-N phenylamino]-3-(l-ethyl-2-methyl-o-3-indolyl)phthalide, 3 ml. of 25% aqueous sodium hydroxide and 50 ml. of hexamethylphosphoramide was stirred I hr. at room temperature and then treated with 3 ml. of ethyl iodide. After stirring at room temperature another 2 hrs. The reaction mixture was poured into water 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 vacuum. The residue was triturated with ligroin to give 0.2 g. of 5-(and 6-)ethoxycarbonyl-3- [N-(4-eth oxyphen yi)-N-phenylamino] - 3-(1-ethyl-2-methyl-3-indolyl)phthalide as a light brown solid, m.p. 86--93"C.

(dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 6.

A mixture containing 5.5 g. of 5-(and 6-)carboxy-3-[N-(4-ethoxyphenyl)-Nphenylamino]-3-(1-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-)noctyloxycarbonyl - 3 - [N - (4 - ethoxy - phenyl) - N - phenylamino] - 3 - (1ethyl - 2 - methyl - 3 - indolyl)phthalide. A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 7.

To a mixture containing 3.0 g. of 5-(and 6-)carboxy-3-[N-(4-ethoxyphenyl)-N phenylamino]-3-( 1 -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 - bromotoluene. After stirring 10 min. the reaction mixture was poured into icewater and the resulting precipitate was collected and dissolved in acetone. The acetone solution was evaporated to dryness and the residue was triturated with ligroin to give 5-(and 6-)benzyloxycarbonyl-3-[N-(4-ethoxyphenyl)-N phenylaminol-3-(1-ethyl-2-methyl-3-indolyl)phthalide as a pale orange solid, m.p.

8085 C. A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange-yellow colored image.

Example 8.

A mixture containing 4.5 g. of 3,4,5,6-tetrachloro-2-(l-ethyl-2-methyl-3- indolylcarbonyl)benzoic acid, 1.0 ml. of thionyl chloride and 200 ml. of 1,2dichloroethane was heated up to the reflux temperature, then cooled to 300 C. 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 5 % aqueous ammonia and the product extracted with 1,2dichloroethane. The organic extracts were washed with water and saturated aqueous sodium chloride and evaporated to dryness. The residue was triturated with cyclohexane to give 3.1 g. of 4, 5, 6, 7-tetrachloro-3-[N-(4-ethoxyphenyl)-N phenyl-aminol-3-(1-ethyl-2-methyl-3-indolyl)phthalilde, 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 phthalide, m.p. 193--194"C. (dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 9.

A. Following a procedure similar to that described in Example 1A but employing 3.1 g. of 2-(1-ethyl-2-methyl-3-indolylcarbonyl)benzoic acid and 1.8 g. of diphenylamine there was obtained 0.78 g. of 3-(1-ethyl-2-methyl-3-ondolyl)-3 (diphenylamino)phthalide, m.p. 125--130"C. (dec.). A toluene 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-diphenylphthalamic acid, 1.6 g. of l-ethyl-2- methylindole, 7 ml. of acetic anhydride and 0.5 ml. of pyridine was stirred several hours at room temperature. The reaction mixture was filtered to remove unreacted N,N-diphenylphthalamic acid. The filtrate was analyzed by thin layer chromatography and shown to contain the desired 3-(1-ethyl-2-methyl-3-indolyl)-3- (diphenylamino)-phthalide identical to the product of part A above contaminated with some 3,3-bis-(1 -ethyl-2-methyl-3-indolyl)phthalide.

C. The reaction of part B above was carried out in the absence of pyridine. The reaction mixture was poured into 5 % aqueous ammonia and the product extracted with toluene. The toluene extracts were washed with water and saturated aqueous sodium chloride and evaporated to dryness. The residue was essentially identical to the product of part B above as indicated by thin layer chromatography.

Example 10.

A mixture containing 7.0 g. of 2-(1.ethyl-2-methyl-3-indolylcarbonyl)-4-(and 5-)nitrobenzoic acid, 4.4 g. of 4-ethoxy-N-phenylaniline, 10 ml. of acetic anhydride and 2 ml. of pyridine was stirred 2 hrs. at room temperature. 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 % aqueous ammonia and the product extracted with toluene. The toluene extracts were washed with water and saturated aqueous sodium chloride and evaporated to dryness under vacuum. The residue was triturated successively with ligroin and 2-propanol to give 1.4 g. of 3-[N-(4 ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3-indolyl)-5 - (and 6 - )nitrophthalide, m.p. 171--173"C. A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 11.

To a stirred mixture containing 7.4 g. of phthalic anhydride and 16.0 g. of 1butyl-2-methylindole at 0--5"C. was added portionwise 13.3g. of aluminum chloride. The mixture was diluted with 50 ml. of benzene and stirred overnight at room temperature. The reaction mixture was poured into 200 ml. of 5 % hydrochloric acid and the product extracted with benzene. The benzene extracts were shaken with dilute aqueous potassium hydroxide. The aqueous alkaline layer was separated, cooled with ice and brought to pH 4 with acetic acid. The precipitated product was collected and dried to give 2-(1-butyl-2-methyl-3indolylcarbonyl)benzoic acid, m.p. 88-920 C. This intermediate was used in the preparation of the compound of Example 17.

Example 12.

Following a procedure similar to that described in Example 11 but employing 7.4 g. of alic anhydride and 16.0 g. of l-n-octyl-2-methylindole there was obtained 6.9 g. of 2-(l-n-octyl-2-methyl-3-indolylcarbonyl)benzoic acid, m.p.

121--123"C. This intermediate was used in the preparation of the compound of Example 18.

Example 13.

A mixture containing 5.0 g. of phthalic anhydride, 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, washed with 1,2dichloroethane and dried to give 3.8 g. of 2 - (2,5 - dimethyl - 3 - ind6lyl- carbonyl)benzoic acid, m.p. 198--200"C. (dec.). This intermediate was used in the preparation of the compound of Example 19.

Example 14.

Following a procedure similar to that described in Example 13 but employing 10 g. of phthalic anhydride and 10 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--203"C. (dec.). This intermediate was used in the preparation of the compound of Example 20.

Example 15.

A. To a stirred mixture of 14.8 g. of phthalic anhydride, 16.2 g. of N-methylpyrrole and 50 ml. of chlorobenzene at e50C. was added portionwise over 1.25 hours.

39.0 g. of aluminum chloride. The temperature was maintained at 2-50C. throughout the addition. After diluting with an additional 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 decanted. 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 acid, m.p. 165--1670C.

B. Following a procedure similar to that described in Example IA but employing 2.3 g. of 2-(N-methyl-2-(and 3-)-pyrrolylcarbonyl)benzoic acid and 2.2 g. of 4ethoxy-N-phenylaniline there was obtained 1.6 g. of 3-[N-(4-ethoxyphenyl)-Nphenylamino] - 3 - (n - methyl - 2 - (and 3-) - pyrrolyl)phthalide, m.p. 1 15--134"C. A toluene solution of the product contacted with acidic clay or phenolic resin developed a yellow colored image.

Example 16.

Following a procedure similar to that described in Example IA but employing 3.43 g. of 2-(9-ethyl-3-carbazolyl-carbonyl)benzoic acid and 2.13 of 4-ethoxy-Nphenylaniline there was obtained 0.73 g. of 3-[N-(4-ethoxyphenyl)-N-phenyl amino]-3-(9-ethyl-3-carbazolyl)phthalide, m.p. 75--850C. (dec.). 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 1A but employing the appropriate 2-(3-indolyl)benzoic acids of Formula II and substituted diphenylamines of Formula III, the following compounds of Formula I, Examples 17-29, wherein n is 0 and Z is were obtained.

m.p. ( C)/ Example R1/R2/R3 Y1/Y2 Y3/Y4 Color Formed 17 n-C4H9 H H 54-92 CH3 H 4-C2H5O yellow-orange H 18 n-C8H17 H H CH3 H 4-C2H5O yello -orange H 19 H H H 145-157 CH3 H 4-(CH3 )2CHO yellow 5-CH3 20 H H H 68-75 (dec.) CH3 H 4-C2H5O yellow-orange 5-CH3O 21 C2H5 H H 171-174 CH3 H 3-CH3 yellow H 22 H H H 66-75 (dec.) CH3 H 4-C2 H5 0 orange-yellow H 23 H H H 103-125 (dec.) CH3 H 4-(CH3)2CHO yellow H 24 C2H5 H H 77-90 CH3 H 4-(CH3)2N brown H 25 C2H5 H H 80-115 CH3 H 2-COOCH3 pink H 26 C2H, H H 76-85 CH3 4-(CH3)2N 4-(CH3)2N grape H m.p. (OC.)/-- Example Rl/R2/R3 Y1/Y2 Y3,Y4 Color Formed 27 C2H5 H H 93-116 CH3 H 4-CH3 CONH yellow H 28 C2H H H 105-121 CH3 4-C,H17 4-arvialkyl yellow H 29 C2H5 H H 106-108 CH3 4-C, H17 4-C5 Hl, yellow H Example 30.

A solution containing 1.46 g. of the color former of Example 1B in 60 ml. of isopropylbiphenyl and a solution containing 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 microscope. 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 following the gradual addition of 670 ml. of water at 500 C. the pH was adjusted to 4.5 with 10 % aqueous acetic acid with continued rapid stirring. After 5 minutes the mixture was cooled to 15 C., treated with 10 g. of 25% aqueous glutaraldehyde and rapidly for 15 minutes. The resulting microcapsule 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 I B produced a yellow colored image on both types of receiving sheets.

Example 31.

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 coated on a transfer sheet. The color former developed an orange colored image on both types of receiving sheets.

Example 32.

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. 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 dispersion of Bisphenol A. The coating mixture as 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 110"C. and 1500C. produced a dark orange image.

Example 33.

A mixture containing 5.4 g. of 2-[4-(dimethylamino)-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 completely dissolved and after 15 minutes an orange solid precipitated. 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 removed an orange impurity) and dried to give 5.9 g. of 3-[4(dimethylamino)phenyl]-3-diphenylaminonaphthalide as a cream solid, m.p. 188-190 C. (dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 34.

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 reactants was 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-phenyl)-N- phenylamino]phthalide as a white solid, m.p. 214-216 C. (dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 35.

A mixture containing 6.24 g. (0.02 mole) of 5-(dimethylamino)-2-[4- (dimethylamino)benzoyl]benzoic acid, 6.25 g. (0.03 mole) of 4-ethoxy-Nphenylaniline and 20 ml. of acetic anhydride was stirred at room temperature for 20 hours. The reaction mixture was then diluted with 30 ml. of 2-propanol and stirred an additional 0.5 hr. The solids were collected, washed with ligroin and dried to give 9.3 g. of 6^(dimethylamino)-3-[4-(dimethylamino)phenyl]-3-[N-(4- ethoxyphenyl)-N-phenylamino]phthalide as a pale pink solid, m.p. 2()(&num;2020C.

(dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image, which, on acidic clay, became green after exposure to fluorescent light.

Example 36.

A mixture containing 2.0 g. of 2-[2,4-bis-(dimethylamino)benzoyl]benzoic acid, 1.4 g. of 4-ethoxy-N-phenylaniline, I ml. of pyridine and 8 ml. of acetic anhydride was stirred 1.5 hrs. at room temperature. Dilution with 20 ml. of 2propanol and 50 ml. of ligroin produced no precipitate. The reaction mixture was therefore poured into 10 % aqueous 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. Trituratin of the residue with ligroin afforded 2.18 g. of 3-[2,4-bis-(dimethylamino)phenyl]-3-[N-(4- ethoxyphenyl)-N-phenylamino]phthalide as a pale orange solid, m.p. 111-117 C.

(dec.). A toluene solution of the product contacted with acidic clay or phenolic resin developed an orange colored image.

Example 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 350C. a solution containing 1.0 g. of 4-ethoxy-N-phenylaniline and a few drops of pyridine in 10 ml. of 1 ,2-dichlorethane was added and stirring at room temperature was continued for 2 days. The reaction mixture was then poured into 10 % aqueous ammonia and the product extracted with 1,2dichloroethane. 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 2propanol to give 1.5 g. of crude 4,5,6,7-tetrachloro-3-[4-(dimethylamino)phenyl]-3 [N-(ethoxyphenyl)-N-phenylamino]-phthalide as a gray solid, m.p. 112-121 C.

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 contacted with phenolic resin produced a pinkish-purple colored image.

Example 38.

Following a procedure similar to that described in Example 33 but employing 3.21 g. of 2-(9julolidinylcarbonyl)-benzoic acid and 2.13 g. of 4-ethoxy-Nphenylaniline there was obtained 4.61 g. of 3-(9-julolidinyl)-3-[N-(4-ethoxyphenyl) N-phenylamino]phthalide, m.p. 143-1470C. A toluene solution of the product contacted with acidic clay or phenolic resin developed a red colored image.

Example 39.

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-[4-(dimethylamino)phenyl] - 3-[N,N-bis-(4-octylphenyl)amino]phthalide, m.p. 158--169"C. 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--167"C.

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 (CVL) and the resulting solution was contacted with phenolic resin with the following results.

Cpd of Ex. 38 CVL Color of image (2% solution) (2% solution) produced 7.0 ml. 3.0 ml. brownish violet black 6.5 ml. 3.5 ml. brownish violet black 6.0 ml. 4.0 ml. violet black 5.0 ml. 5.0 ml. bluish black Example 40.

A. Following a procedure similar to that described in Example 36 but employing 3.1 g. of 2-[4-(diethylamino)-2-methylbenzoyllbenzoic acid and 3.0 g. of 4,4'bis(dimethylamino)-diphenylamine there was obtained 2.95 g. of 3-[4 (diethylamino)-2-methylphenyll-3-[N-(4-dimethylaminophenyl) - N - (4 - dimethylaminophenyl)amino]phthalide, m.p. 67--83.5"C. A toluene solution of the product contacted with acidic clay or phenolic resin developed 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(dimethylamino)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 dissolved in 200 ml. of DMF and slowly added to 1+ liters of water containing 1 g of Dabco (Registered Trade Mark) with vigorous stirring.

The air dried product was weighed 5.0 g. and was essentially identical to the product of part A above.

C. In a procedure similar to that described in Example 37, 1.7 g. of thionyl chloride was added to a mixture of 100 ml. of benzene and 50 ml. of l,2-dichloroethane.

After 4.7 g. of 2-[4-(diethylamino-2-methylbenzoyl]benzoic acid was added, the reaction mixture was warmed to 600 C. to obtain a clear solution. When the solution had cooled to 400 C., a solution of 3.5 g. of 4,4'-bis(dimethylamino)diphenylamine and 1 ml. of pyridine in 50 ml. I ,2-dichloroethane was added and the mix heated to 600 C. for one hour, cooled and stirred overnight at room temperature.

The tary material which separated was filtered, washed and dissolved in dimethylformamide. Addition to an excess of water yielded 4.2 g. of a light grapecolored solid which developed a black color on silica gel.

Example 41.

A. To a stirred mixture containing 36 g. of 4-(and 5-)-carboxy-2-(4-diethylamino-2- hydroxybenzoyl)benzoic acid (prepared from trimellitic anhydride and 3 (diethylamino)phenol, 60 ml. of diethyl sulfate and 450 ml. of acetone at 35"C. 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 96"C. The reaction mixture was maintained at 96"C. 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-(4-diethyl-amino-2-ethoxybenzoyl)benzoic acid, m.p.

63--96"C. which was used without further purification.

B. A mixture containing 8.0 g. of 4-(and 5-)carboxy-2-(4-diethylamino-2ethoxybenzoyl)benzoic acid, 8.0 g. of 4-dimethylamino-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 wa m.p. ( C.) Example Q/n R7/R8/R9 Y1/Y2 Y3Y4 Color Formed 42 6-(CH3)2N H H H 159-160 1 CH3 H H red CH3 43 - CH3 H H 176-178 (dec.) 0 C2H5 H 4-C2H5O red C2H5 44 - H H H 185-187 0 CH3 H 3-CH3 orange CH3 45 - H H H 181-184 0 CH3 H 4-(CH3)2CHO orange CH3 46 - CH3 H H 176-178 0 C2H5 H 4-(CH3)2CHO red C2H5 47 - H H H 63-68 (dec.) CH3 H 4-C2H5O orange p-CH3O-C6H4 m.p. ( C.) Example Q/n R7/R8/R9 Y1/Y2 Y3Y4 Color Formed 48 - H H H 81-95 (dec.) 0 CH3 H 4-OH orange CH3 49 - CH3 H H 173-175 (dec.) 0 C2H5 H H red C2H5 50 - CH3 H H 155-156 0 C2H5 H 3-CH3 red C2H5 51 - CH3 H H 85-110 0 C2H5 4-C8H17 4-C3H17 red C2H5 52 - H 3-C2H5 3-C2H5 0 CH3 5-C9H19 5-C9H19 yellow CH3 53 - Cl H H 0 CH3 H 4-C2H5O red CH3 m.p. ( C.) Example Q/n R7/R8/R9 Y1/Y2 Y3Y4 Color Formed 54 - H H H 128-138 0 CH3 H 3-Cl orange CH3 55 - H H H 163-166 0 CH3 H 4-(CH3)2N brown CH3 56 6-(CH3)2N H H H 163-164 1 CH3 H 4-(CH3)2N brown CH3 57 - CH3 H H 154-156 0 C2H5 H 4-(CH3)2N grape C2H5 58 - H H H 92.5-102 0 CH3 H 2-COOCH3 yellow CH3 59 - CH3 H H 51-126 0 C2H5 H 2-COOCH3 orange C2H5 m.p. ( C.) Example Q/n R7/R8/R9 Y1/Y2 Y3Y4 Color Formed 60 - H H H 67-143 0 CH3 4-(CH3)2N 4-(CH3)2N brown CH3 61 - H H H 182-184.5 0 CH3 H 4-NHCOCH3 orange CH3 62 - CH3 H H 169-171 0 C2H5 H 4-NHCOCH3 red C2H5 63 - CH3 H H 179-182 0 C2H5 4-NHCOCH3 4-NHCOCH3 red C2H5 64 6-(CH3)2N H H H 148-152 1 C2H5 H 4-C2H5O orangeb C6H5CH2 65 - H H H 163-173 0 C2H5 H 4-C2H5O orange C6H5CH2 m.p. ( C.)/ Example Q/n R7/R8/R9 Y1/Y2 Y3/Y4 Color Formed 66 - CH3 H H 0 C2H5 4-C8H17 4-arylalkyl red C2H5 67 6-(CH3)2N H H H 208-210 1 CH3 4-C8H17 4-C8H17 orangeb CH3 68 C2H5O H H 0 C2H5 4-C8H17 4-C8H17 orange C2H5 69 - C2H5O H H 126-131 0 C2H5 H 4-NHCOCH3 orange C2H5 70 - CH3 H H 172-174 0 CH3 4-C8H17 4-C8H17 red CH3 71 - CH3 H H 58-71 0 C2H5 4-(C2H5)2N 4-(C2H5)2N black C2H5 m.p. ( C.)/ Example Q/n R7/R8/R9 Y1/Y2 Y3/Y4 Color Formed 72 - CH3 H H 68-83 0 C2H5 4-(C2H5)2N 4-(CH3)2N black C2H5 73 - H H 67-84 0 CH3 4-(C2H5)2N 4-(CH3)2N black CH3 74 - C2H5O H H 58-69 0 C2H5 4-(CH3)2N 4-(CH3)2N grape-black C2H5 75 - CH3 H H 97-113 0 CH3 4-(CH3)2N 4-(CH3)2N black CH3 76 - CH3 H H 59-72 0 CH3 4-(C2H5)2N 4-(C2H5)2N black CH3 77 6-(CH3)2N H H H 86-92 1 CH3 4-(CH3)2N 4-(CH3)2N brownb CH3 m.p. ( C.)/ Example Q/n R7/R8/R9 Y1/Y2 Y3/Y4 Color Formed 78 6-(CH3)2N H H H 137-148 1 C2H5 4-(CH3)2N 4-(CH3)2N brown b C6H5CH2 a) Prepared according to the procedure of Example 36.

Another preparation carried out in a manner similar to that described in Example 33 afforded a product m.p. 176-179 C. b) Changed to green on acidic clay after exposure to fluorescent light.

Example 79.

The color formers of Examples 34 and 42 were microencapsulated as follows.

A solution containing 1 g. of the color former in 49 g. of isopropylbiphenyl and a solution containing 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 microscope. 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 following the gradual addition of 670 ml. of water with heating (at 50 C.) 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 (12g.) was gradually added to 60 ml. of water. The mixture was heated to 90 C. and stirred 15 minutes. After cooling to room temperature the mixture was added to 473 g. of the above microcapsule dispersion and the resulting emulsion stirred vigorously for 2 minutes, and then 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 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.

Example 80.

Polyvinyl alcohol dispersions of the color formers of Examples 34, 35 and 42 were 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. 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 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 1100C. and 150"C. 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.

Example 81.

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

Example 82.

Following a procedure similar to that described in Example 79 but omitting the addition of starch to the microcapsule dispersion, the color former of Example 40 was microencapsulated and coated on a transfer sheet. The color former developed a black image on both types of receiving sheets. The image formed on the claycoated receiving sheet turned green on standing.

Example 83.

Following procedure similar to that described in Example 79 but omitting the addition of starch to the microcapsule 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. The mixture of color formers developed a blue to black image on resin-coated receiving sheets.

By following procedures similar to those described in the foregoing Examples but employing the appropriate 2-(3-indolyl) or [(4-disubstitutedamino)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

Examples 118-149, are obtained.

PHTHALIDES OF FORMULA I - Z =

Ex. Q n R1 R2 84 5-(CH3)2N 1 n-C18H37 CH3 85 6-(C2H5)2N 1 n-C14H29 CH3 86 6-(n-C4H9)2N 1 CH3 C6H5 87 4-NO2 1 (CH3)2CH(CH2)8 H 88 5-Br 1 C2H5 CH3 89 6-F 1 C2H5 C2H5 90 7-Cl 1 n-C6H13 CH3 91 Br 4 H CH3 92 I 4 C2H5 CH3 93 F 4 C2H5 CH3 94 4,7-(Cl)2 2 n-C3H7 CH3 95 5,6-(Br)2 2 CH3 CH3 96 4,5,7-(Cl)3 3 C2H5 CH3 97 6-CO2-n-C18H37 1 C2H5 CH3 98 5-CO2-(CH2)8CH(CH3)2 1 C2H5 CH3 99 6-CO2-n-C4H9 1 CH3 CH3 100 5-CO2-n-C14H29 1 C2H5 CH3 PHTHALIDES OF FORMULA I - Z =

Ex. R3 Y1 Y2 Y3 Y4 84 H H H 4-OH H 85 H H H 3-Cl H 86 H H H 2-C2H5 H 87 H H H 3-I H 88 5-(CH3)2CHCH2 H H 4-Br H 89 6-C2H5 H H 3-(CH3)3C H 90 H 2-CH3 H 4-CH3O H 91 5-(CH3)2CHO 3-Br H 5-Br H 92 6-CH3O H H 2-F H 93 4-CH3 2-Cl H 4-F H 94 7-C2H5O 3-CH3O H 3-CH3O H 95 5-n-C3H7 3-CH3 4-CH3 3-CH3 4-CH3 96 H 3-n-C4H9O H 3-n-C4H9O H 97 H 2-CL 4-Cl 2-Cl 4-Cl 98 H H H H H 99 5-n-C4H9O H H 4-n-C6H13 H 100 H H H 4-C2H5O H PHTHALIDES OF FORMULA I - Z =

Ex. V n R1 R2 101 1 H H S-CO2 Na 102 6-CO?NH4O+ 1 CH1 CH1 0 103 6-CO2 HN(C2H5)3 1 C2H1 CH1 104 6-CO2 H2N(n-C4H9)2 1 C2H5 CH1 105 S-C02-C2 Hs NH W r n ul lo m m m e 106 N N N N 0N±n-C15 H17 1 C2H5 N N N = 107 S-CO?H0N±C4H9)1 1 C2H5 CH1 0+ 108 6-C09 fl-Ca H17 NH (n-C4H9)2 I CH2 CH3 109 0 CaHa CH1 110 0 C2H5 CH2 111 0 C2H1 CH3 U S-C02C2H5 H O O O H O CH1 CH1 113 6-CO2CH1 1 C2H5 CH1 114 0 C2H5 CH3 115 0 C2H5 CH1 116 0 C1H1 CH2 u" 3hm 117 Cl 4 CH1 CH3 (3Z N N = = &verbar; N 83 2 G ) N (3) N ) (9 (&commat; N N - r r r - r r r U . N t m F 00 0s 0 ~ 6 v7 t m vD > x o o O o o Ho O O O ~ H ~ H H ~ H

PHThALIDBS OF FORMULA I - Z Ex. Ba Yi A Yl Y4 101 H H H 4-C2H50 H o 3: U N 9 H H 4-(CH1)2CHO H e t e H 3: t H H d H 105 6-CH3 H H 4-C2H10 H 106 H H H 4-Cl H 107 6-Cl110 H H 4CH3O H 108 H H H 4-C2H90 H 109 H 4-NH2 H 4-NH2 H 110 H 4-NHCOC4H9 H H H 111 H 4-NHC4H9 H 4-NHC4H9 H 112 H = N 113 H 4-CQQH9 H H H X N U H 4-CH2C6H5 H H H 115 H 4-CH-CH2H5 H H H C P1 117 6-CH1 4-NHCH(CH1)2 o H H &verbar; X $ $ X vo $ qv $ $ X $ $ :C $ $ X $ x ~ n t un so > oo as o ~ c9 t m \ ls s o o o o o o o o o ~ < ~ H ~ PHTHALIDES OF FORMULA I - Z =

Ex. Q n R7 R8 118 - 0 n-C4H9 CH3 119 5-(C2H5)2N 1 H CH3 120 5-Br 1 Br CH3 121 4,5,6,7-(Br)4 4 (CH3)2N CH3 122 - 0 C2H5O C2H5 123 5-(C4H9)2N 1 H CH3 124 6-F 1 H CH3 125 5-Cl 1 H t-C4H9 126 4,5,6,7-(F)4 4 H CH3 127 - 0 (sec-C4H9)2N sec-C4H9 128 4,5,6,7-(I)4 4 H CH3 129 - 0 I C4H9 130 6-(C2H5)2N 1 H C2H5 131 6-(C4H9)2N 1 H CH3 132 - 0 (CH3)2CHCH2O CH3 133 5-COOCH2C6H5 1 H CH3 PHTHALIDES OF FORMULA I - Z =

Ex. Ra Y1 Y4 118 CH H H 3-I H ^ X~ ;t~$ 120 m v, $r H 4-Br H 121 CH2 H H 3-(t-C4H9) H 122 C2H5 2-CH1 H 4-CH1O H 123 C2H5 3-Br H S-Br H 124 C6H5 H H 2-F H 125 t-C4H9 2-Cl H 4-F H > :: $ $ $ X $ $ $ $ X $ t $ $ D X 127 sec-C4H9 H H H H 128 CH1 H H 4-OH H 129 p-C4H9-C6H4 3-CH1 4-CH1 3-CH1 4-CH O O X CH1 131 CH3 X X 3-QH5-C H CH1 132 CH1 CI 4-Cl CI 4-Cl 133 rl 4-CH1C6H5 H H H . oo ofi o H ot t m qx b oo o ^ es x ~ H Ot ot bt N > Ot Ot Ot ot O1 n n Jr CE PHTHALIDES OF FORMULA I - Z =

Ex. Q n R7 R8 134 6-COOC8H17 1 C2H5 C2H5 135 5-COOC18H37 1 Cl CH3 136 5-COOC14H29 1 H CH3 137 6-COO(CH2)8CH(CH3)2 1 CH3 C2H5 138 5-COOH 1 H CH3 139 - 0 H CH3 140 - 0 CH3 C2H5 141 4,5,6,7-(Cl)4 4 H CH3 142 - 0 CH3 C2H5 143 - 0 CH3 C2H5 144 5-COO-Na+ 1 H CH3 145 6-COO-NH4+ 1 H CH3 146 5-COO- HN+(C2H5)3 1 H C2H5 147 5-COO-H3+NC18H37 1 CH3 C2H5 148 6-COO-H3+NC8H17 1 H CH3 149 - 0 CH3 C2H5 PHTHALIDES OF FORMULA I - Z =

Ex. $ $ $ $ Rw Y1 Y2 Y1 Y4 o $ > CH1 4-CHCH2 t H5 H H H N F C2H5 CO2CH1 H H H 138 CH1 2-CO2H H H H 139 CH1 4-NH2 H H H 140 C2H5 4-NH2 H 4-NH2 H 141 CH1 4-NHC4H9 H 4-NHC4H9 H Y, I 0 u" e" 39 5 143 = 4-NHCOC4H9 H O ~ U < U Q U Z : < ; z; 2 z 9 144 CH1 uu,uuu H H H u S $ ^ " X CH1 H H H H C U U D V D U U C-) w s D > 00 Cr = r H n t m > < e e * t t t t PHTHALIDES OF FORMULA I - Z =

Ex. R9 Y1 Y2 Y3 Y4 146 C6H5CH2 4-OC2H5 H H H 147 C2H5 H H H H 148 CH3 4-OC2H5 H H H 149 C2H5 4-NHCH(CH3)2 H H H

Claims (63)

1. WHAT WE CLAIM IS:- l. A compound having the Formula I (herein) wherein: Q is di-lower-alkylamino, nitro, halo or COX, where X is hydroxyl, benzyloxy, alkoxy having from l 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 NR5Re, where R4 and Ba are hydrogen or lower-alkyl and Ba is hydrogen, loweralkyl, cycloalkyl having from 5 to 7 carbon atoms, or lower alkanoyl; Z is

   A t > < or or 9-julolidinyl R,R N R7 in which: R is hydrogen or non-tertiary alkyl having from l to 4 carbon atoms; R1 is hydrogen, or non-tertiary alkyl having from 1 to 18 arbons atoms; R2 is hydrogen, phenyl or non-tertiary alkyl having from 1 to 4 atoms; R3 is hydrogen, non-tertiary alkyl having from 1 to 4 carbon atoms or nontertiary alkoxy having from 1 to 4 carbons atoms; R, is hydrogen, halo, lower-alkyl, lower-alkdxy or di-lower-alkylamino; Ra is lower-alkyl; and Ba is lower-alkyl, beazyl, phenyl or phenyl substituted with a lower-alkyl or lower-alkoxy group.
2. 2. A compound according to claim 1, wherien R3 is hydrogen; R7 is hydrogen or lower-alkyl; and R9 is lower-alkyl or benzyl.
3. 3. 3-[N,n-Bis-(3-ethyl-5-nonylphenyl)amino]-3-(1-ethyl-2-methyl-3indolyl)phthalide.
4. 4. A compound according to claim 2, wherein Y, and Y3 are each hydrogen.
5. 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. 6. A compound according to claim 5, wherein n is 0.
7. 7. 3 - [N - (4 - Ethoxyphenyl) - N - phenylamino] - 3 - (1 - ethyl - 2- methyl - 3 indolyl)phthalide.
8. 8.3-(N,N-Diphenylamino)-3-(1-ethyl-2-methyl-3-indolyl)-phthalide.
9. 9.3-[N-(3-methylphenyl)-N-phenylamino]-3-(1 - ethyl - 2 - methyl - 3indolyl)phthalide.
10. 10. 3 - (1 - Ethyl - 2 - methyl - 3 - indolyl) - 3 - [N,N - bis - (4 - octyl phenyl)amino]phthalide.
11. 11. 3 - [4 - (Dimethylamino)phenyl] - 3 [N - (4 - ethoxyphenyl) - Nphenylamino]phthalide.
12. 12. 3 - [4 - (Dimethylamino)phenyl] - 3 - [N - (4 - isopropoxyphenyl) - Nphenylamino]phthalide.
13. 13. 3 - [4 - (Diethylamino) - 2 - methylphenyl] - 3 - [N - (4 - ethoxyphenyl) - Nphenylamino]phthalide.
14. 14. 3 - [4 - (Dimethylamino)phenyl] - 3 - [N,N - bis - (4 - octylphenyl) amino]phthalide.
15. 15. 3- [4(Diethylamino)phenyl]-3-(N,N-diphenylamino)-phthalide.
16. 16. 3 - [4 - (Ethylbenzylamino)phenyl] - 3 [N - (4 - ethoxyphenyl) - Nphenylamino]phthalide.
17. 17. 3 - [4 - (Diethylamino) - 2 - methylphenyl] - 3 - {N,N - bis[4 (dimethylamino)phenyl]amino]phthalide.
18. 18. A compound according to claim 5, wherein n is 1 and Q is di-loweralkylamino.
19. 19. 6-(Dimethylamino)-3-[4-(dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl) N-phenylamino]phthalide.
20. 20. 6 - (Dimethylamino - 3 - [4 - (dimethylamino)pheny1] - 3 - [N,N - bis(4octylphenyl)amino]phthalide.
21. 21. A compound according to claim 9, wherein Q is halo and n is 1 to 4.
22. 22. 4,5,6,7-Tetrachloro-3-(1-ethyl-2-methyl-3-indolyl)-3-[N-ethoxyphenyl) N-phenylamino]phthalide.
23. 23. 4,5,6,7-Tetrachloro-3-[4-(dimethylamino)phenyl]-3-[N-(4-ethoxyphenyl) N-phenylamino]phthalide.
24. 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. 25. 5-Carboxy-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3- indolyl)phthalide.
26. 26. 6-Carboxy-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl-2-methyl-3indolyl)phthalide.
27. 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 I to 18 carbon atoms.
28. 28. Tert-octylammonium 3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl- 2-methyl-3-indolyl)phthalide-5-carboxylate.
29. 29. Tert-octylammonium 3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl2-methyl-3-indolyl)phthalide-6-carboxylate.
30. 30.5 - (Methoxycarbonyl) - 3 - [N - (4 - ethoxyphenyl) - N - phenylamino] 3 - (1 - ethyl - 2 - methyl - 3 - indolyl)phthalide.
31. 31. 6 - (Methoxycarbonyl) - 3 - [N - (4 - ethoxyphenyl) - N - phenylamino]- 3 - (1 - ethyl - 2 - methyl - 3 - indolyl)phthalide.
32. 32. 5-(Ethoxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl 2-m-ethyl-3-indolyl)phthalide.
33. 33. 6-(Ethoxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl2-methyl-3-indolyl)phthalide.
34. 34. 5-(Octyloxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenylamino]-3-(1-ethyl2-methyl-3-indolyl)phthalide.
35. 35. 6-(Octyloxyvarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenylaminol-3-(1 1-ethyl 2-methyl-3-indolyl)phthalide.
36. 36. 5-(Benzyloxycarbonyl)-3-[N-(4-ethoxyphenyl)-N-phenylaminol-3-(1 1-ethyl2-methyl-3-indolyl)phthalide .
37. 37. 6-(B enzyloxycarbonyl)-3- [N-(4-ethoxyphenyl)-N-phenylamino]-3- (l-ethyl-2-methyl-3-indolyl)phthalide.
38. 38. A compound according to claim 1, wherein Z is

    and Y1, Y2, Y3, and Y4 do not include phenyl-lower-alkyl, COOR4 or NR5Ba.
39. 39. A compound according to claim 1, wherein Z is

    and at least one of Y1, Y2, Y3 and Y4 is phenyl-lower-alkyl, COOR4 or NR5R6.
40. 40. A compound according to claim 1, wherein (Q)n in formula I is

    wherein: Q4 is hydrogen or halo; Q5 is the same as Q4; or di-lower-alkylamino or halo when Q4, Q6 and Q7 are each hydrogen; Q0 is the same as Q4; or di-lower-alkylamino or halo when Q4, Q5 and Q7 are each hydrogen; and Q, is the same as Q4; and Z is

    or 9-julolidinyl and Y1, Y2, V3 and V4 do not include phenyl-lower-alkyl, COOR4 or NR,R,.
41. 41. A compound according to claim 1, wherein (Q)n in Formula I is

    wherein Q4 is hydrogen or halo; Q6 is the same as Q4; or di-lower-alkylamino, COX or halo when Q4, Q6 and Q7 are each hydrogen; Q0 is the same as Q4; or di-lower-alkylamino, COX or halo when Q4, Q5 and Q, are each hydrogen; and Q, is the same as Q4; and Z is

    or 9-julolidinyl and either Q5 or Q6 is COX or at least one of V1, V2 V3 and V4 is phenyl-lower-alkyl, COOT, or NBaRa.
42. 42. A process for producing a compound according to any one of claims 1 and 38 to 41, which comprises 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, 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.
43. 43. A process according to claim 42, wherein the anhydride of an alkanoic acid having from 2 to 5 carbon atoms is acetic anhydride and the organic base is a diarylamine, pyridine or urea.
44. 44. A process for producing a compound according to any one of claims I and 38 to 41, which comprises reacting a 2-substituted benzoic acid having the Formula II (herein) with thionyl chloride, phosphorus oxychloride, phosphorus trichloride or phosphorus pentachloride; and reacting the resulting product with a diarylamine having the Formula III (herein) in the presence-of an organic base, where Q is limited to di-lower-alkylamino, nitro, halo or COX' wherein X' is as defined in claim 42.
45. 45. A process according to claim 44, wherein said inorganic acid chloride is thionyl chloride and said organic base is a diarylamine, pyridine or urea.
46. 46. A process for producing a compound according to any one of claims 1, 38 and 39, wherein Z is

    which comprises reacting a phthalamic acid having the Formula IV (herein) with an indole having the Formula V (herein) wherein Q is limited to di-lower-alkylamino, nitro, halo or COX', wherein X' is as defined in claim 42.
47. 47. A process according to any one of claims 42 to 46, in which the compound obtained wherein Q is COOH is subjected to the action of an esterifying agent and is thereby converted to the corresponding compound wherein Q is COX" where X" is benzyloxy or alkoxy, or is subjected to the action of a salifying agent and is thereby converted to the corresponding compound wherein Q is COOM wherein M is an alkali metal cation, an ammonium cation or a mono-, di- or tri-alkyl ammonium cation having from I to 18 carbon atoms.
48. 48. A process for preparing a compound according to claim 1, substantially as herein described with reference to Examples 1--23, 30--32 and 84-108.
49. 49. A process for preparing a compound according to claim 1, substantially as herein described with reference to Examples 24-29 and 109-117.
50. 50. A process for preparing a compound according to claim 1, substantially as herein described with reference to Examples 33-39, 42-54, 79, 80 and 118-132.
51. 51. A process for preparing a compound according to claim 1, substantially as herein described with reference to Examples 40, 41, 55-78, 81-83 and 133-149.
52. 52. A compound when prepared by the process according to any one of claims 42 to 51.
53. 53. A compound according to claim 1, substantially as herein described with reference to Examples 1--23, 30--32 and 84-108.
54. 54. A compound according to claim 1, substantially as herein described with reference to Examples 24-29 and 109-117.
55. 55. A compound according to claim 1, substantially as herein described with reference to Examples 33-39, 42-54, 79, 80 and 118-132.
56. 56. A compound according to claim 1, substantially as herein described with reference to Examples 40, 41, 55-78, 81-83 and 133-149.
57. 57. A pressure-sensitive carbonless duplication system or thermal marking system containing a color-forming substance comprising a compound according to any one of claims 1 to 41, and 52 to 56.
58. 58. A pressure-sensitive carbonless duplication system according to claim 57, comprising a support sheet coated on one side with a layer of pressure-rupturable microcapsules, containing a liquid solution of the color-forming substance.
59. 59. A thermal marking system according to claim 57, comprising 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.
60. 60. 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.
61. 61. A system according to claim 60, in which the definition of the compound is further limited according to any one of claims 38 to 41.
62. 62. A pressure-sensitive carbonless duplicating system or thermal marking system according to claim 57, substantially as herein described with reference to the Examples.
63. 63. A system according to claim 60 or 61, substantially as herein described with reference to the Examples.