Fogged Direct-Positive Silver Halide Emulsion Containing a Cyanine Dye Having an Indole or Indolenine Nucleus Substituted With a Benzoyl or a Phenylsulfonyl Group

EXAMPLE 1

2-Phenyl-5-phenylsulfonyl-1H-indole. ##STR15## 87 g. of 4-(acetophenone)-hydrazone-diphenylsulfone was completely mixed with 450 g. of anhydrous ZnCl.sub.2 and then heated at 180.degree. C. for 3 hours on a thermoregulated oil bath. The cake, thus obtained, was ground in a mortar and poured under stirring into 4 l. of 20% hydrochloric acid. The product was collected on a filter and washed with water. The raw product was crystallized from ethyl alcohol, thus obtaining 46 g. of indole having a M.P.= 207.degree.-208.degree. C.

EXAMPLE 2

2-Phenyl-5-benzoyl-1H-indole. ##STR16## 100 g. of 4-(benzoyl)-acetophenone-phenyl-hydrazone was mixed with 500 g. of anhydrous ZnCl.sub.2 and then heated at 190.degree. C. for 2 hours on a thermoregulated oil bath. The cake, thus obtained, was ground in a mortar and poured under stirring into 4 l. of 20% hydrochloric acid. The solid obtained was extracted many times with ether; the ethereous extracts were treated with anhydrous CaCl.sub.2 and evaporated to dryness. 17 g. of indole was obtained having a M.P.= 233.degree. C.

EXAMPLE 3

1-Methyl-2-phenyl-5-phenylsulfonyl-indole. ##STR17## 182 g. of 4-N-acetophenone-N'-methyl-hydrazone-diphenyl-sulfone was completely mixed with 750 g. of anhydrous ZnCl.sub.2 and then heated at 160.degree. C. per 4 hours on a thermoregulated oil bath. The pick cake obtained was ground in a mortar and poured under stirring into 5 l. of 20% hydrochloric acid. The product was collected on a filter and repeatedly washed with water. The pure indole was extracted with ethyl ether, thus obtaining 42 g. of pure product having a M.P.= 165.degree. C.

EXAMPLE 4

2-Phenyl-3-formyl-5-phenylsulfonyl-1H-indole. ##STR18## 5 g. of 2-phenyl-5-phenylsulfonyl-1H-indole and 20 ml. of anhydrous dimethyl formamide were poured into a 250 ml. flask equipped with a mechanical stirrer, a reflux condenser and a dropping funnel. Vilsmeier's reagent was separately prepared by mixing 5 g. of phosphoryl chloride with 4.5 g. of anhydrous dimethyl formamide. This reagent was dropped into the indole solution maintaining the temperature under 40.degree. C.; at the end of the addition, the mixture was kept at 45.degree. C. for 45 minutes. After chilling at 20.degree. C., the reaction mixture was poured into 500 ml. of water; the white solid, thus obtained, was collected on a filter and well washed with water. The raw product was purified by crystallization from acetic acid obtaining 2.5 g. of a pure product melting at 262.degree. C.

Example 5

2-Phenyl-3-formyl-5-benzoyl-1H-indole. ##STR19## The product was obtained as described in Example 4, using 5 g. of 2-phenyl-5-benzoyl-1H-indole dissolved in 5 ml. of anhydrous dimethylformamide and 9 ml. of the Vilsmeir's reagent, obtained by mixing 4 ml. of phosphoryl chloride and 5 ml. of anhydrous dimethyl formamide. After recrystallization from acetic acid, 2.7 g. of pure product was obtained having a M.P.= 285.degree. C.

Example 6

1,1'-dimethyl-2,2'-diphenyl-5,5'-diphenylsulfonyl-3,3'-indolocarbocyanine chloride. ##STR20## A mixture of 3.6 g. of 1-methyl-2-phenyl-5-phenylsulfonyl-indole and 1.25 g. of .beta.-anilino-acroleinaldehyde-anil-hydrochloridrate in 20 ml. of acetic anhydride was refluxed adding 1 ml. of concentrated hydrochloric acid slowly. The mixture was heated to boiling for 3 minutes and then cooled. It was then poured into ethyl ether and the obtained dye was collected on a filter and dried. Yield: 3.3 g. (equal to 78% of the theoretical yield). After crystallization from hydrochloric acid acidified ethyl alcohol, a pure dye was obtained which had a M.P.= 177.degree.-180.degree. C.

EXAMPLE 7

1,1'-H-2,2'-diphenyl-5,5'-dibenzoyl-3,3'-indolocarbocyanine acetate. ##STR21## The dye was prepared as described in Example 6, using acetic acid instead of hydrochloric acid, starting from 1-H-2-phenyl-5-benzoyl-indole. M.P.= 250.degree.-253.5.degree. C. .lambda. max.= 604 nm. (dimethylformamide-ethyl alcohol).

EXAMPLE 8

1-H-3'-ethyl-5-phenylsulfonyl-6'nitro-2-phenyl-3-indolothiacarbocyanine iodide. ##STR22## 1.75 g. of 2-methyl-3-ethyl-6-nitro-benzothiazole iodide and 1.8 g. of 2-phenyl-3-formyl-5-phenylsulfonyl-1H-indole were dissolved in a mixture consisting of 20 ml. of acetic anhydride and 10 ml. of acetic acid. The reaction mixture was refluxed for 3 minutes and then cooled at room temperature. The raw dye was filtered on a buckner, washed with alcohol and ethyl ether and dried in a desicator at 50.degree. C., thus obtaining 2.7 g. of a raw dye. It was then crystallized from a mixture consisting of 25 ml. of dimethylformamide and 25 ml. of ethyl alcohol. Yield: 1.12 g. of pure dye melting at 327-332.degree. C. .lambda. max. = 501 nm. (ethyl alcohol).

EXAMPLE 9 1-H-3'-ethyl-5-benzoyl-6'-nitro-2-phenyl-3-indolo-thiacarbocyanine iodide. ##STR23## The synthesis was performed as described in Example 8, using 1.75 g. of 2-methyl-3-ethyl-6-nitro-benzothiazole iodide and 1.72 g. of 2-phenyl-3-formyl-5-benzoyl-indole. Yield: 2.5 g. of raw dye, which was purified by recrystallization from a mixture of 40 ml. of dimethylformamide and 40 ml. of ethyl alcohol. 1.58 g. of pure dye was obtained having a M.P.= 198.degree.-203.degree. C. .lambda. max.= 511 nm. (ethyl alcohol).

EXAMPLE 10

1-Methyl-3'-ethyl-5-phenylsulfonyl-6'-nitro-2-phenyl-3-indolothiacarbocyani ne iodide. ##STR24## The dye was prepared as described in Example 9, using 1.65 g. of 2-methyl-3-ethyl-6-nitro-benzothiazole iodide and 1.4 g. of 1-methyl-2-phenyl-3-formyl-5-phenylsulfonyl-indole. 1.0 g. of pure dye was obtained having a M.P. 330.degree. C. .lambda. max.: 498 nm. (ethyl alcohol - dimethylformamide).

EXAMPLE 11

1-Methyl-1'-ethyl-5,5'-di-(phenylsulfonyl)-2-phenyl-3',3'-dimethyl-indocarb ocyanine iodide. ##STR25## 2.27 g. of 1-ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine iodide, 1.87 g. of 1-methyl-2-phenyl-3-formyl-5-phenylsulfonyl-indole and 15 ml. of acetic anhydride were mixed in a 50 ml. flask and heated to boiling for 30 minutes. The dye was separated from the reaction mixture upon cooling, filtered on a buckner and washed with ethyl alcohol, thus obtaining 2.3 g. of raw dye. After crystallization from 150 ml. of a mixture consisting of dimethylformamide/ethyl alcohol in a ratio of 1:2, by concentration to half volume and upon cooling 1.1 g. of pure dye was obtained. M.P. - 234.degree.-5.degree. C. .lambda.max.:= 506 nm. (ethyl alcohol-dimethyl formamide).

EXAMPLE 12

1-Methyl-1'-ethyl-5-phenylsulfonyl-5'-benzoyl-2-phenyl-3',3'-dimethyl-indoc arbocyanine iodide. ##STR26##

EXAMPLE 13

1-Cyanoethyl-1'-ethyl-3',3'-dimethyl-5,5'-di-(phenyl-sulfonyl)-2-phenyl-ind ocarbocyanine iodide. ##STR27##

EXAMPLE 14

1-Methyl-2-phenyl-5-phenylsulfonyl-3'-.OMEGA.-sulfobutyl-6'-nitro-3-indolo- thiacarbocyanine-anhydrous-hydroxide. ##STR28##

EXAMPLE 15

1-Methyl-2-phenyl-1'-.omega.-sulfobutyl-5,5'-di-(phenylsulfonyl)-3', 3'-dimethyl-indocarbocyanine-anhydrous-hydroxide. ##STR29##

EXAMPLE 16

2,3,3-Trimethyl-5-phenylsulfonyl-indolenine. ##STR30## A mixture of 53.5 g. of anhydrous ZnCl.sub.2 and 42 ml. of absolute ethyl alcohol was poured into a 250 ml. keller beaker provided with thermometer, mechanical stirrer, reflux condenser and gas inlet tube and heated up to a temperature of 120.degree.-130.degree. C. The obtained solution was cooled and the keller was put on an oil bath thermoregulated at 75.degree. C. At this temperature, under stirring and bubbling with a slow stream of hydrogen, 26 g. of 4-methyl-isopropylketone-hydrazone-diphenylsulfone were added during 5 minutes. The hydrogen bubbling was continued for 3 hours keeping the reaction mixture at 85.degree.-90.degree. C. After cooling at 30.degree. C., 45 ml. of 2% HCl was added under stirring. A solid product separated (Zn salt of the base). It was then filtered on a buckner and processed with 35 ml. of a 20% KOH water solution under stirring and heating up to about 80.degree. C. After cooling at room temperature, a yellow product separated. This was then collected on a buckner and washed with water. The raw product was crystallized from ligroin, thus obtaining 14.2 g. of a base melting at 138.degree.-140.degree. C.

EXAMPLE 17

2,3,3-Trimethyl-5-benzoyl-indolenine. ##STR31## The base was prepared as described in Example 11, using 220 g. of anhydrous zinc chloride, 140 ml. of absolute ethyl alcohol, 95 g. of 4-methyl-isopropyl-ketone-hydrazone-benzophenone and 200 ml. of 2% HCl. The zinc salt of the base was treated with 150 ml. of 20% of a KOH aqueous solution. The base separated as an oil which was extracted with ether. The ethereal extracts were evaporated to dryness and the remaining liquid was purified by vacuum distillation. The product distilled from 183 to 185.degree. C. at 0.5 mm. Hg. was collected. Yield: 46 g.

EXAMPLE 18

1-Ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine p-toluene-sulfonate. ##STR32## 15 g. of 2,3,3-trimethyl-5-phenylsulfonyl-indolenine and 10 g. of ethyl p-toluene-sulfonate were heated at 115.degree. C. for 8 hours in a pressure flask on a thermoregulated oil bath. The pick cake obtained by cooling was ground in a mortar washed with ether and dried.

EXAMPLE 19

Anhydro-1-.omega.-sulfobutyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine hydroxide. ##STR33## A mixture of 12 g. of 2,3,3-trimethyl-5-phenylsulfonyl-indolenine and 6.12 g. of 1,4-butansultone was heated at 120.degree. C. for 3 hours. The solid cake obtained by cooling was ground in a mortar by washing repeatedly with ethyl ether. The product was dried in a desicator at 40.degree. C., thus obtaining 16.3 g. of salt. The product was used as it was for the synthesis of the dyes.

EXAMPLE 20

Anhydro-1-.omega.-sulfobutyl-2,3,3-trimethyl-5-benzoyl-indolenine hydroxide. ##STR34## A mixture of 10.5 g. of 2,3,3-trimethyl-5-benzoyl-indolenine and 6.12 g. of 1,4-butanesulfone was heated at 120.degree. C. for 3 hours. The pick cake obtained was ground in a mortar by washing repeatedly with ethyl ether. The product was dried in a desicator at 50.degree. C., obtaining 7.1 g. of salt which were used without any further purification for the synthesis of the dyes.

EXAMPLE 21

1-Ethyl-2-formyl-methylene-3,3-dimethyl-5-phenylsulfonyl-indolenine. ##STR35## 28 ml. of a mixture consisting of 10 ml. of phosphoryl chloride and 18 ml. of dimethyl-formamide was added to a solution made of 27 g. of 1-ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine iodide and 75 ml. of dimethyl-formamide. The mixture was heated on a water bath for 45 minutes and then poured into 900 ml. of ice and water. The mixture was rendered basic by the addition of 30% NaOH and then refluxed for 8 hours. Upon standing and cooling, a solid separated. It was collected on a buckner and washed with water until the washings were neutral. After a crystallization from a 1:1 ligroin-benzene mixture, 13.5 g. of pure product were obtained. M.P.: 175.degree.-176.5.degree. C.

EXAMPLE 22

1-Ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine iodide. ##STR36## A mixture of 60 g. 2,3,3-trimethyl-5-phenylsulfonyl indolenine and 36 ml. of ethyl iodide was heated at 110.degree. C. for 8 hours on a thermo-regulated oil bath. After cooling the pick cake obtained was ground in a mortar by washing with acetone and ethyl ether and then dried in a desicator at 50.degree. C. 36.7 g. of product were obtained. M.P.: 210.degree.-213.degree. C.

EXAMPLE 23

1-Ethyl-2,3,3-trimethyl-5-benzoyl-indolenine p-toluene-sulfonate. ##STR37## A mixture of 2.63 g. of 2,3,3-trimethyl-5-benzoyl-indolenine and 2.4 g. of ethyl p-toluene-sulfonate was heated at 120.degree. C. for 8 hours in a pressure flask on a thermoregulated oil bath. The cake obtained by cooling was ground in a mortar by washing with ethyl ether, dried under vacuum and used immediately for dye snythesis because it was deliquescent.

EXAMPLE 24

1,1'-Diethyl-3,3,3',3'-tetramethyl-5,5'-diphenylsulfonyl-indocarbocyanine iodide. ##STR38## A mixture of 1-ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine iodide and 12 ml. of triethylorthoformiate in 60 ml. of pyridine was heated to reflux for 6 hours. After cooling, the mixture was poured into ethyl ether under stirring; the separated gum became solid upon repeated washings with ether. After crystallization from ethyl alcohol, 1.3 g. of pure dye were obtained, having a M.P.: 270.degree.-275.degree. C. (decomposition). .lambda. max.= 556 nm. (ethyl alcohol).

EXAMPLE 25

1,1'-diethyl-3,3,3',3'-tetramethyl-5,5'-dibenzoylindocarbocyanine iodide. ##STR39## The dye was prepared as described in Example 19 using 1.4 g. of 1-ethyl-2,3,3-trimethyl-5-benzoyl-indolenine iodide, 2 ml. of triethylorthoformiate and 5 ml. of pyridine. The raw dye was purified by crystallization from ethyl alcohol, obtaining 0.4 g. of pure dye having a M.P.= 295.degree.-298.degree. C. .lambda. max.= 563 nm. (ethyl alcohol).

EXAMPLE 26

1,3'-diethyl-5-phenylsulfonyl-6'-nitro-3,3-dimethyl-indo-thiacarbocyanine iodide. ##STR40## A mixture of 1.77 g. of 1-ethyl-2-formylmethylene-3,3-dimethyl-5-phenylsulfonyl-indoline and 1.75 g. of 2-methyl-3-ethyl-6-nitrobenzothiazole iodide in 30 ml. of acetic anhydride and 15 ml. of acetic acid was heated to reflux for 5 minutes. By cooling, the dye separated as green crystals with golden reflexes; it was then collected on a buckner, washed with ethyl alcohol and ethyl ether and dried in a desicator at 50.degree. C. After crystallization from 12.5 ml. of dimethylformamide, 1.3 g. of pure dye were obtained having a M.P.: 240.degree.-245.degree. C. .lambda. max.= 563 nm. (ethyl alcohol).

EXAMPLE 27

1,3'-Diethyl-5-phenylsulfonyl-3,3-dimethyl-indo-oxacarbocyanine iodide. ##STR41## A mixture of 1.77 g. of 1-ethyl-2-formylmethylene- 3,3-dimethyl-5-phenylsulfonyl-indoline and 0.87 g. of 2-methyl-3-ethyl-benzoxazole iodide in 15 ml. of acetic anhydride was heated to reflux for 5 minutes. The reaction mixture, poured into ethyl ether, separated a gum, which became solid upon repeated washings with ethyl ether. The raw dye was collected on a bunkner and dried in a desicator at 50.degree. C. After a crystallization from 15 ml. of a 1:2 dimethylformamide ethyl alcohol mixture, 1.5 g. of pure dye were obtained having a M.P.= 178.degree.-181.degree. C. .lambda. max.= 537 nm. (ethyl alcohol).

EXAMPLE 28

Anhydro-1-.omega.-sulfobutyl-3'-ethyl-5-phenylsulfonyl-6'-nitro-3,3-dimethy l-indo-thiacarbocyanine hydroxide. ##STR42## A mixture of 4.3 g. of anhydro-1-.omega.-sulfobutyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine and 2.5 g. of 2-formylmethylene-3-ethyl-6-nitro-benzothiazoline in a mixture of 25 ml. of acetic anhydride and 12.5 ml. of acetic acid was heated to reflux for 10 minutes. After cooling, the reaction mixture was poured into ethyl ether under stirring. The separated solid was collected on a buckner and washed immediately with many portions of ethyl ether. The raw dye was boiled twice in 100 ml. of ethyl acetate and crystallized from 25 ml. of acetic acid, thus obtaining 3 g. of a pure dye melting at 308.degree.-311.degree. C. .lambda. max.= 566 nm. (ethyl alcohol).

EXAMPLE 29

Anhydro-1-.omega.-sulfobutyl-3'-ethyl-5-benzoyl-6'-nitro-3,3-dimethyl-indo- thiacarbocyanine hydroxide. ##STR43## A mixture of 1.5 g. of anhydro-1-.omega.-sulfobutyl-2,3,3-trimethyl-5-benzoyl-indolenine hydroxide and 1.2 g. of 2-formylmethylene-3-ethyl-6-nitro-benzothiazoline in a mixture of 20 ml. of acetic anhydride and 7 ml. of acetic acid was heated to reflux for 15 minutes. After cooling, the reaction mixture was poured into ether under stirring; a solid dye separated after a night standing. The dye was then filtered on a buckner and washed with ethyl ether. The yield of the raw dye was 2.37 g. which were crystallized from ethyl alcohol, thus obtaining 1.0 g. of pure dye. M.P.= 240.degree.-248.degree. C. .lambda. max.= 572 nm. (ethyl alcohol). .lambda. max.= 559 nm (methyl alcohol+ dimethylformamide)

EXAMPLE 30

3-Phenyl-1-[(1'-ethyl-3',3'-dimethyl-5'-phenylsulfonyl-indolenine-2'-yliden e)-ethylidene]-2-isoxazoline-5-one. ##STR44## 1.7 g. of 1-ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine p-toluene-sulfonate and 0.9 g. of 3-phenyl-4-anilino-methylene-2-isoxazoline-5-one were dissolved in 15 ml. of pyridine containing 2 ml. of triethylamine and refluxed at 130.degree. C. for 16 hours. After cooling, the reaction mixture was poured into 200 ml. of water acidified with acetic acid. The separated gum was washed many times with water, dissolved in acetic acid and precipitated with water. The dye, which separated, was used directly to prepare the dye of Example 31.

EXAMPLE 31

2-Ethyl-3-phenyl-4-[(1'-ethyl-3',3'-dimethyl-5'-phenylsulfonyl-indoline-2-y lidene)-ethylidene]-2-isoxazoline-5-one iodide. ##STR45## 2.49 g. of the merocyanine of Example 30 and 7.5 ml. of diethylsulfate were reacted at 120.degree. C. for 15 minutes. After cooling, the gum, thus obtained, was washed repeatedly with 50 ml. portion of ethyl ether. The product, thus obtained, was dissolved in 20 ml. of ethyl alcohol and 1.6 g. of potassium iodide, dissolved in 5 ml. of water, added thereto. The separated gum became solid upon repeated washings with water. The raw product was crystallized from ethyl alcohol, thus obtaining 1.3 g. of pure dye. M.P.= 219.degree.-224.degree. C. .lambda. max.= 462 nm. (ethyl alcohol).

EXAMPLE 32

1-Ethyl-2-[3-(2,5-dimethyl-1-phenyl-3-pyrrolyl)-vinyl]-3,3-dimethyl-5-pheny lsulfonyl-indolenine perchlorate. ##STR46## A mixture of 1.5 g. of 1-ethyl-2,3,3-trimethyl-indolenine p-toluene-sulfonate and 0.59 g. of 1-phenyl-2,5-dimethyl-3-formylpyrrole (prepared as described in British Pat. No. 746,998) in 15 ml. of boiling ethyl alcohol was added with 0.5 ml. of acetic anhydride and refluxed for 4 hours. 0.5 g. of ammonium perchlorate dissolved in water was added to the hot reaction mixture. The raw dye separated upon cooling. It was then dried in a desicator at 50.degree. C. and crystallized from a 3:1 ethyl alcohol-dimethylformamide mixture, thus obtaining 0.4 g. of pure dye. M.P.= 268.degree.-271.degree. C. .lambda. max.= 494 nm. (ethyl alcohol).

EXAMPLE 33

1-Methyl-1'-ethyl-2-phenyl-5-nitro-5'-phenylsulfonyl-3',3'-dimethyl-indocar bocyanine iodide. ##STR47## A mixture of 1.87 g. of 1-ethyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine p-toluene-sulfonate and 1.5 g. of 1-methyl-2-phenyl-3-aldehydo-5-nitro-indole (prepared as described in French Pat. No. 1,599,796) in a mixture consisting of 15 ml. of acetic anhydride and 7.5 ml. of acetic acid was refluxed for 5 minutes. After cooling, the mixture was poured into ether. A gum separated. It was then redissolved with 20 ml. of hot ethyl alcohol and precipitated with 0.6 g. of potassium iodide dissolved in water. The dye separated upon heating up to the boiling point and further cooling of the precipitation. The dye was then dried in a desicator at 50.degree. C. Yield: 1.6 g. The raw dye was crystallized from 25 ml. of a 1:1 dimethylformamide-ethyl alcohol, thus obtaining 0.5 g. of pure dye. M.P.= 268.degree.-271.degree. C. .lambda. max.= 507 nm. (ethyl alcohol dimethylformamide).

EXAMPLE 34

1-Ethyl-3,3-dimethyl-1'-methoxy-2'-phenyl-5-phenylsulfonyl-indocarbocyanine perchlorate ##STR48##

EXAMPLE 35

1-Methyl-1'-ethyl-2-phenyl-5-nitro-5'-benzoyl-3',3'-dimethyl-indocarbocyani ne iodide ##STR49## 2.09 g. of 1-ethyl-2,3,3'-trimethyl-5-benzoyl-indolenine iodide, 1.4 g. of 1-methyl-2-phenyl-3-formyl-5-nitro-indole and 15 ml. of acetic anhydride were heated to boiling for 15 minutes. When still hot, the dye separated; it was then filtered and washed with ethyl alcohol. The raw dye, thus obtained, was crystallized from a mixture of dimethylformamide and ethyl alcohol. The raw dye, thus obtained, was crystallized from a mixture of dimethylformamide and ethyl alcohol in a ratio of 1:3. 0.87 g. of pure dye was obtained. M.P.: 245.degree.-7.degree. C. .lambda. max.: 505 nm. (ethyl alcohol-dimethylformamide).

EXAMPLE 36

1-Methyl-1'-.omega.-sulfo-butyl-2-phenyl-5-nitro-5'-phenylsulfonyl-3',3'-di methylindocarbocyanine anhydrous hydroxide ##STR50##

EXAMPLE 37

(1-Ethyl-3,3'-dimethyl-5-phenylsulfonyl-indolenine-2)-(1',3'-diallyl-imidaz o-[4,5-b]-quinoxaline-2)-trimethincyanine p-toluene-sulfonate ##STR51##

EXAMPLE 38

Anhydro-1-(.omega.-sulfo)-butyl-2-p-diethylamino-styryl-3,3-dimethyl-5-benz oyl-indolenine hydroxide. ##STR52## A mixture of 3.99 g. of anhydro-1-.omega.-sulfobutyl-2,3,3-trimethyl-5-benzoyl-indolenine hydroxide and 1.77 g. of p-diethylaminobenzaldehyde in a mixture consisting of 20 ml. of acetic anhydride and 10 ml. of acetic acid was heated to boiling for 10 minutes. After cooling, the dye was precipitated with ethyl ether; the separated gum became solid upon repeated washings with ether. The raw dye was collected on a buckner and crystallized from ethyl alcohol, thus obtaining 3 g. of pure dye, M.P.= 179.degree.-183.degree. C. .lambda. max.= 579 nm. (ethyl alcohol).

EXAMPLE 39

Anhydro-1-.omega.-sulfobutyl-2-p-diethylamino-styryl-3,3-dimethyl-5-phenyls ulfonyl-indolenine hydroxide. ##STR53## The dye was obtained as described in Example 38 using 4.35 g. of anhydro-1-.omega.-sulfobutyl-2,3,3-trimethyl-5-phenylsulfonyl-indolenine hydroxide and 1.77 g. of p-diethylamino-benzaldehyde. After crystallization from ethyl alcohol, the pure dye had a M.P. equal to 188.degree.-192.degree. C. Yield: 1.5 g. .lambda. max.= 578 nm. (ethyl alcohol).

EXAMPLE 40

2-Diphenylamino-5-[(1-ethyl-3,3-dimethyl-5-phenylsulfonyl-indoline-2-yliden e)-ethylidene]-2-thiazoline-4-one. ##STR54## A mixture consisting of 1.77 g. of 1-ethyl-2-formyl-methylene-3,3-dimethyl-5-phenylsulfonyl-indoline, 1.34 g. of 2-diphenylaminothiazoline-4-one and 15 ml. of piperidine was heated to reflux for 20 minutes. The dye separated upon cooling. It was then filtered on a buckner, washed with ethyl alcohol and ether and crystallized from a 1:1 ethyl alcohol-dimethylformamide mixture. Yield of the pure dye: 1.9 g. M.P.= 275.degree.-280.degree. C. .lambda. max.= 458 nm. (ethyl alcohol-dimethylformamide).