DE2218800A1 - Merocyanine dyes - Google Patents

Description

DR. BERG DIPL.-ING. STAPF

PATENTANWÄLTE 8 MUNICH 8O. MAUERKIRCHERSTR.

PATENT LAWYERS 2 ^ 1 OO UU

Dr. Mount Dipi.-lng. Stapf, 8 Manchen 80, MauerkircherstroSe 45

No. 22276

Your letter Our sign date

22276 18th i ». 1972

ILPORD LIMITED Hf ord, Essex / England

Merocyanine dyes

The present invention relates to merocyanine dyes and to silver halide emulsions which contain these dyes as optical sensitizers.

According to the present invention, erocyanine dyes the general formula

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= CH - CH = C

A-

created,

in the R .. a lower alkyl, aralkyl or aryl radical, R ₂ an alkyl, hydroxyalkyl, aralkyl, carboxy-substituted aralkyl, carboxy-substituted alkyl radical, a radical - (CH ₀ ) SO ^ H , where η is an integer from 1-6, an acylsulfamoylalkyl radical of the formula "(CH ₀ ) SO ₀ NHCOR., where η is an integer from 1-6, and R. an alkyl radical or an alkyl or aralkylsulfamoylalkyl radical of the Formula - (CH ₀ ) SO ₀ NHR ₅ , v.'O η is an integer from 1-6, and R _{1 is} an alkyl or aralkyl radical, one of the radicals R- and R _{3 is} a chlorine or bromine atom and the other is a hydrogen atom and A is a thiohydantoin or 2-thio-2,4-oxazolidinedione ring.

Where R _{0 is} a carboxy or sulfone radical, the dye can be obtained as a salt.

The alkyl radicals are preferably lower alkyl radicals with

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1- ^ 4 carbon atoms and especially methyl or ethyl radicals, but can also be higher alkyl radicals. Suitable aralkyl radicals are benzyl and phenylethyl radicals. Aryl radicals can be phenyl or naphthyl radicals. The above-mentioned ferocyanine dyes are valuable optical sensitizers for silver halide photographic emulsions for the purpose of forming the emulsions to give an increased sensitivity. They can be in silver bromide, silver chloride, silver chlorobromide or Silver iodobromide emulsions in amounts of the same order of magnitude as the usual cyanine sensitizing agents Dyes may be included. The invention accordingly further includes silver halide photographic emulsions one, especially gelatin silver halide emulsions, which contain one or more dyes of the formula Γ in sensitizing Quantities included.

The merocyanine dyes of the formula I generally act as green-colored optical sensitizing dyes and are especially used in color silver halide photographic Material used because they tend to coupler the decolorizing effect of nouns when in a silver halide dye emulsion.

Thus, according to another aspect of the present invention, there is provided a silver halide photographic emulsion composed of a substan-209847/1044 '~ ⁴ ~

tive purple color coupler and a merocyanine dye of the general. Formula I consists. In accordance with another aspect of the present invention there is provided a method for making merocyanine dyes created according to the general formula I, which is characterized in that it is the implementation of a Compound of formula

R.

F ₃ CFO ₂

with a compound of the formula

= CH - N

in which R ₁ , R 3, R ₃ , R- and A are as defined above, X is an anion and R _{g is} a hydrogen atom, an acyl radical or an arylsulfone radical, in the presence of a basic condensing agent. According to another embodiment of this aspect of the present invention, a process for the fractionation of merocyanine dyes according to the general

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_ 5 -

NEN formula I created, which is characterized in that it is the implementation of a compound of the formula

N - CH

CO-.

with a compound of the formula

- CH,

in which R- ,, R ₂ , R ₃ , R ₃ and A are as defined above, X is an anion and Rg is a hydrogen atom, an acyl or arylsulfonyl radical , in the presence of a basic condensing agent.

A suitable basic condensing agent is tri-ethylamine.

The following preparations illustrate the preparation the chlorine- and bromine-substituted benzimidazole bases,

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Manufactures

1. Preparation of 6-chloro-1-ethyl-2-methyl-5-trifluoro methyl-sulfonyl-benzimidazo!

F ₃ CO ₂ P

- CH.

A. 24.8 g (0.085 mol) of 1-ethyl-2- methyl-5-trifluoro-me- thylsulfonyl-benzimidazole v / earth in portions to one Nitration mixture consisting of 8.5 ml of fuming nitric acid and 50 ml of concentrated sulfuric acid, added with stirring at 40 ° C. When the addition is finished is, the temperature is increased to 50 ° C and then the apparatus is placed on a boiling water bath and heated with stirring for 1 hour. The mixture is cooled and poured onto 500 g of crushed ice. The mixture is made alkaline with 250 ml of aqueous ammonia. The supernatant liquids are decanted and the semi-solid product extracted with chloroform (2 times 150 ml). The solution is washed with water, separated and chloroform distilled off. The "pro-

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The product is dissolved in 180 ml of ethanol, filtered off and recrystallized. 22.5 g (78.7%) 6-nitro-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazole are obtained as yellow crystals with a melting point of 172-175 ° C.

6-Amino-1-ether-2-methyl-5-trifluoromethylsulfonyl-bengimidazole

B. 22.5 g (0.066 mol) of l-lithyl-2-methyl-6-nitro-5-trifluoromethylsulfonyl-benzimidazole are dissolved in 110 ml of boiling methanol and a solution of 44.5 g of tin (II) chloride in 45 ml concentrated in portions to the solution Added hydrochloric acid and the solution slowly heated to reflux temperature for 2 hours, then cooled and made strongly alkaline with 190 ml of 40% sodium hydroxide solution. The mixture is made with 650 ml Diluted water and the precipitate filtered off. The filter cake and the filtrate are made with chloroform (120 ml) extracted. The chloroform extracts are washed with water (2 × 200 ml) and separated, the chloroform solution filtered off and chloroform distilled off. The amino compound is dissolved in 120 ml of ethanol and filtered off and 120 ml of water are added to the filtrate. The diluted filtrate is heated to boiling, to dissolve the product again, and cooled. 12.6 g

(62.4%) 6-amino-1-ethyl-2-methyl-5-trifluoromethylsul- 209 847 / 104A - 8 -

fonyl-benzimidazole as a solid with a Melting point of 199 - 2O2 ° C obtained.

6-chloro-1-ethyl, -2-methyl-5-trifluoromethane sulfonylbenzimidazo!

C. 16.6 g (0.054 t! Ol) of G-fluoromethylsulfonyl-benzimidazole are dissolved in a mixture of 6.8 ml of concentrated hydrochloric acid and 17.5 ml of water with stirring. Additional 14.5 ml of concentrated hydrochloric acid are added and the mixture cooled ⁰ C by external cooling to O and by dropwise addition of a solution of 3.8 g of sodium nitrite in 10 ml water at 0 - 5 ° C diazotized. The clear diazo solution is added in a steady stream to a stirred solution of copper (I) chloride at 35.degree. The copper (I) chloride solution is prepared as follows: 16.5 g of copper (II) sulfate (CuSO ₄ ) and 5.3 g of sodium chloride are dissolved in 53 ml of water at 60 - 70 ° C, 2.7 g of sodium bisulfite are added, stirred and allowed to cool. The failed copper (I). Chloride is filtered off and dissolved in a mixture of 27.3 ml of water and 20.8 ml of concentrated hydrochloric acid.

When the addition of the diazo solution is complete, this will Stir. Continued for 5 minutes. The mixture is then heated on a boiling water bath for 1/4 hour. The mixture is cooled and an excess (160 ml)

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aqueous ammonia added.

The product is extracted with chloroform (2 × 150 ml). The chloroform extracts are washed with dilute ammonia and water. The chloroform solution is filtered off and chloroform distilled off. The residue is dissolved in 50 ml of ethanol, filtered off and cooled. 7.6 g (43%) 6-chloro-1-ethyl-2-methyl-5-trifluoromethyl-sulfonyl-benzimidazole .are obtained as pale yellow crystals with a melting point of 170-173 ° C.

2. Preparation of 6-bromo-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazo l

12.3 g (0.04 mol) of 6-2 ^ mino-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazole are in a mixture of 20 ml of 48% hydrobromic acid and 40 ml of water dissolved with stirring. The mixture is cooled from the outside and at 0-5 ° C. with a solution of 2.8 g of sodium nitrite diazotized in 8 ml of water. The diazonium

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suspension is poured in a steady stream in a stirred solution of copper (I) bromide (CuBr). in 30 ml of 48% Given hydrobromic acid at 50 ° C. A dark brown one Oil is separated out with vigorous evolution of nitrogen. The mixture is diluted with 160 ml of water and at Stirred at 50 C until development almost stops. The mixture is then stirred for 1/2 hour on a boiling water bath. The mixture is cooled and excess aqueous ammonia (120 ml) is added. The supernatant liquid is decanted and with Chloroform extracted (2 × 10 ml). The solid is then dissolved in the chloroform extract and the Solution is washed with dilute aqueous ammonia (1: 1) and then with water. The chloroform solution is filtered off and chloroform is distilled off leaving a brown oil which on cooling solidified to a pale yellow solid. The solid is dissolved in aqueous methanol (1: 1) and filtered off and recrystallized. The product is filtered off, washed with water and dried. The product is recrystallized a second time from 50 ml of isopropanol. 6.4 g (43.1%) 6-bromo-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazole are obtained as a pale yellow solid with a melting point of 162-163 ° C.

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The following examples illustrate the invention,

example 1

F ₃ CO ₂ S

C = CH - CH = C

CO - N Ό - CS

5- (6-chloro-1,3-diet-5- ~ trifluoromethylsulfonyl-2-benzimldazolinylidene) ~ ethylidene-3-ethyl-2-thio-2y4-oxazolidinedion.

1.92 g (O _r OO4 mol) 6-chloro-1 _f 3-diethyl-2-methyl-5-trifluoromethylsulfonyl-benziiaidazoliniurajodid and 1.16 g 5- (acetanilidomethylene) -3-ethyl-2-thio-2- , 4-oxazolidinedione in 30 ml of pyridine and 1.6 ml of triethylamine are heated at reflux temperature for 3/4 hours. Pyridine was distilled off under reduced pressure. The residue was washed with water and dried. The dye was 2 times from a mixture of ethylene glycol monomethyl ether and Kthanol (3: 1) to give. 1.16 g of copper bronze crystals with a melting point of 264-266 ° C. were obtained. The dye had., - ,, an absorption maximum in ethanol at 500 nm, log q 5.12.

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- 12 -

When the dye is in a silver chlorbramide emulsion was incorporated, 'so the sensitivity expanded 565 nm off, with a maximum at 545 ran.

Example 2

F ₃ CO ₂ F

= CH - CH = C

^C 2 ^H 5

<T2 ^H 5

CO

"N - CS

5- (6-chloro-1 _r 3-diethyl-5-trifluoromethol-sulfonyl-2-benzimidazolinylidene) ethylidene-S-ethyl-1-phenyl- ^ - thiohydantoin

3.13 g (0.005 moles) of 6-chloro-2- / 2- (N-phenylacetamido) vinyj-5-trifluoromethylsulfonyl-benzimidazolinium iodide and 1.0 g of 3-ethyl-1-phenyl-2-thiohydantoin in 30 ml of pyridine and 2.0 ml of triethylamine were refluxed for 3/4 hours. Pyridine was reduced under Distilled pressure. The residue was dissolved in 50 ml of chloroform. The solution was made with 2% hydrochloric acid and washed with water, the chloroform solution was removed "was filtered off and chloroform was distilled off. The dye was recrystallized twice from ethanol. There were

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'2 09847/1 044

1.0 g of purple crystals with a melting point of 276-278 ° C obtained. The dye had an absorption ' tion maximum in ethanol at 518 nm, log £ 5.06. When the dye is incorporated into a silver chlorine xomide emulsion V7urde, the sensitivity "expanded 565 nm off, with a maximum at 550 nm.

Example 3

F ₃ CO ₂ S

C _n H,

? 2 ^H 5

CO - N

= CH - CII = C,

0 - CS

O ₂ H ₅

5- (1,3-Diethyl-6-bromo-5-trifluomethylsulphonyl-2-benzene-tnidazolinylidene) ethylidene-3-ether-2-thio-2,4-oxazolidinedione

2.10 g (0.004 mol) of 6-bromo-1,3-diethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazolinium iodide and 1.16 g-5- (acetanilidomethylene) -3-ethyl-2-thio-2,4-oxazolidinedione v / urden in 25 ml of n-butanol and 1.6 ml of triethylamine Heated at reflux temperature for 3/4 hours. The dye, which crystallized out on cooling, was filtered off and washed with dilute ethanol. The dye was dissolved in chloroform and dried over neutral aluminum

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miniuiuoxyd chromatographed using chloroform. The dye was recrystallized twice from a mixture of isopropanol / xthanol / acetone (5: 3: 2). Yield: 1.25 g of pink-bronze crystals with a melting point of 244 - 245 ° C. The dye had an absorption maximum in ethanol at 502 nm, log f 5.13. When the dye was incorporated into a silver chlorobromide emulsion, the sensitivity was extended to 565 nm, with a maximum at 550 nm.

Example 4

5- (1-Benzyl-6-bron) -3 ~ ethyl-5-trifluoromethane sulfonyl- 2-benzimidazole nvlidene) ~ ethylidene ~ 3 ~ ether-2-thio-2 _f 4-oxazolidinedione

Br.

CF ₃ SO ₂

- CH =

CO-N - C ₉ H 0 -CP

A mixture of 6-bromo-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazole (1.27 g) and eenzyl bromide (0.4 ml) were heated to 120 ° C for 2 hours. The implementation of the quaternary salt obtained with 5- (acet-

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anilidomethylene) -3-ethyl-2-thio-2,4-oxazoliäindione
(0.87 g), analogously to Example 3, gave the dye, which was obtained as purple-red crystals with a melting point of 219 to 221 ° C. by recrystallization from ethanol. When the dye was incorporated into a silver chlorobromide emulsion, the sensitivity of the dye extended to 575 nm with a maximum at
555 nm.

CF ₃ _SO ₂

Example 5

Triethylammonium-6-bromo-3-ethyl-2- (3-ethyl-4-oxo-2-thioxo-5-oxazolidinylidene) ethylidene-5-trifluoromethyl sulfonyl-1-benzimidazoline acetate

CO-N-C ₂ H ₅

= CH - CH =

0 - CS

CH ₂ -CO ₂

EN (C_R_) -,
2l 5 ο

A mixture of 6-bromo-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazole (1.27 g) and bromoacetic acid (0.5 g) were heated at 150 ° C for 2 hours. The received quaternary salt was made with 5- (acetanilidomethylene) -3-ethyl-2-thio-2,4-oxazolidinedione (0.87 g) implemented analogously to Example 3. The dye was identified as a purple color

2 09847/1044

ne crystals with a melting point of 185-186 ° C. obtained by recrystallization from ethanol. Is T * ^T hen the dye in a silver chlorobromide emulsion incorporated, the sensitivity at 565 nm extends from, nm with a maximum at the 550th

Example 6

Triethvlamraonium-6-bromo-3-ethyl-2- (3-ethyl-4-oxo-2-thioxo-5-oxazolidinylidene) -ethylidene-5-trifluoromethyl sulfonyl-1-benzimidazoline propanesulfonate

.CO - N - C _O H _C 2. b

CF ₃ SO ₂

- CH =

O - CS

3 - ^p

HN (C ₂ H ₅ )

A mixture of 6-bromo-1-ethyl-2-methyl-5-trifluoromethylsulfonyl-benzimidazole (1.27 g) and 1,3-propane sultone (0.5 g) were heated to 150 ° C for 2 hours. The reaction of the quaternary salt obtained with 5-acetanilido-methylene) -3-ethyl-2-thio-2,4-oxazolidine ^ dione (0.87 g), analogously to Example 3, gave the dye, as red-brown crystals with a melting point from 243 - 245 ° C after recrystallizing twice

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2 09847/1044

Ethanol was obtained. "

Example 7

5 '(6-chloro-l, 3-d iäthyl-5-trifl uormethyls ulfonyl-2 ~ benzimidazolinyliden) -äthyliden-1, S-, hydantoin

CF ₃ SQ ₂

- CH «

N - CS CH- »

CH

A mixture of 6-chloro-X, 3-diethyl-2- [2- (lsl-'phenyl ·

zolinium iodide (3.24 g), 1,3-dimethyl-2-thiohydantoin (0.72 g), n-butanol (20 ml) and triethylamine (1.5 ml) was refluxed for 30 minutes. The cooled mixture was filtered off, the piltrate under reduced pressure The pressure was evaporated to dryness and the product was chromatographed over aluminum oxide in chloroform solution. The sluice of the red main band and the evaporation of the eluate gave the dye, which from aqueous ethanol was recrystallized, He was called obtained black-red crystals with a melting point of 138 to 140 ° C.

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Example 8 5 ~ (7-chloro- 1,3-aiethvl ~ 5-trifluorr " ethvlBulfon vl-2-

benzii uidazolinyliden) -S

oxazolidinedione ^CF 3 ^PO 2

, CO -

N - C ₂ H ₅

■ = CH - CH =.

- CS

^C 2 ^H 5

A mixture of 7-chloro-1,3-diethyl-2- [2- (N-phenylacetamido) vinyl] -5-trifluoromethylsulfonyl-benzimidazolinium iodide (1.56 g) , 3-ethyl-2-thio- 2 _/ 4-oxazolidinedione (0.36 g), pyridine (15 ml) and triethylamine (0.8 ml) were refluxed for 45 minutes. The dye was isolated and purified analogously to Example 2 when it is obtained as orange-red crystals with a melting point of 296-298 ° C. When the dye is incorporated into a silver chlorobromide emulsion, the sensitivity extends to 565 nm, with a maximum at 540.

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Claims (7)

Claims F ₃ CSO ₂ in which R is a lower alkyl, aralkyl or aryl radical, R _{2 is} an alkyl, hydroxyalkyl, aralkyl, carboxy-substituted aralkyl, carboxy-substituted alkyl radical, a radical - (CH ₀ ) SO-, Η, where η is a is an integer from 1-6, an acylsulfamoylalkyl radical of the formula - (CH ₀ ) SO ₀ NHCOR-, ντο η is an integer from 1-6, and R- is an A-alkyl radical or an alkyl or aralkylsulfairoylalkyl radical of the Forrael - ( CH ₀ ) SO ₉ NHRt-, where η is an integer from 1-6, and R ₁ - is an alkyl or Aralkyl radical, one of the radicals R ₃ and R_ is chlorine or bromine and the other is a hydrogen atom, and A completes a thiohydantoin or 2-thio-2,4-oxazolidinedionrina. 209847 / 1OAA - 20 - 2. Merocvanin dye according to claim 1 of the general formula C = CIT - CH = C, ' F ₃ CSO ₂ ^R 2 in which R, a lower alkyl, aralkyl or aryl radical, R ₂ an alkyl, hydroxyalkyl, aralkyl, carboxy-substituted aralkyl, carboxy-substituted alkyl radical, a radical - (CH ₀ ) SO ₀ H, where η an integer & XT * 5 from 1 - 6, an acylsulfamoy.lalkylrest of the formula - (CH ₀ ) SO ₀ NKCOR., where η is an integer from 1-6, C * Xl α- * x and R _{4 is} an alkyl radical or an alkyl or aralkylsulfamoylalkyl radical of the formula - (CH ₀ ) SO ₀ NHRc-, where η is an integer from 1-6, and R _{5 is} an alkyl or aralkyl radical, R _{3 is} chlorine or Bromine and A complete a thiohydantoin or 2-thio-2,4-oxazolidinedione ring. 3. Process for the production of a merocvanin dye of formula I of claim 1, characterized in that it is the reaction of a compound of the general formula - 21 - 209847 / 10U CH ₀ with a compound of the general formula F ₃ CSO ₂ = CH - N in which R _{1, R 3} , R ₃ , R ₃ and A have the meaning given in claim 1, X is an anion and Rg is a hydrogen atom, an acyl radical or an arylsulfonyl radical, in the presence of a basic condensing agent. · 4. Photographic silver halide emulsion, characterized in that it is used in a sensitizing amount at least one merocyanine dye according to claim 1 contains. 5. Silver halide photographic emulsion according to claim 4, characterized in that it further contains a purple dye coupler which is then sub- 209847/1044 - 22 - is stantivated. 6. Photographic material, characterized in that it contains at least one photographic silver halide emulsion according to claim 4 contains. 7. Photographic material, characterized in that it contains at least one photographic silver halide emulsion according to claim 5 contains. 209847/1044