CA1142921A - Red colors - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Red colors having the anthraquinone structure are disclosed wherein R1 and R2 are independently selected from among hydrogen, halo, lower alkyl, lower alkoxy, nitro, and sulfonate, and X
represents halogen or -NR3R4, wherein R3 and R4 are independently selected from hydrogen, alkyl and alkylsulfonate. Precursors are disclosed as well.

Description

This inv:ention relates to colorants. More particularly, it concerns a family of red colorants which find special application as red colorants for edibles.
FD~C Red #2, a monoazo dye of the formula HO SO3Na N 03 ~ N = ~

S03Na commonly known as Amaranth, was among the most widely used colors in foods, drugs and cosmetics. In 1975 these uses were prohibited in the United States when the Food and Drug Administration ruled that the dye's safety was questionable. The removal from commerce of this compound has left a great need. Edibles such as cherry, raspberry, and strawberry-flavored gelatin desserts, beverages, candies and jams, and nonedibles such as inks and dyes were formulated around the particular tint and hue of this color. Several replacement colors have been proposed but have not been fully acceptable.
For example, FD~C Red #40, another monoazo dye which has the formula NaO3S~ ~ O ~ N = N

S03Na

2 !~

and which is d~sclosed in United States Patent 3764a,733, issued February 8, 1972 to Rast et al, is now being used as a replacement. This material has a brownish cast which interferes with many uses. Natural colors, such as are extracted from ~eets, have ~een suggested as well but have low coloring power~
and thus unaccepta~ly high costs in use. The present lnventlon seeks to provide a replacement for now-delisted azo color Red #2, This invention discloses a l~mited family Or new anthraquinone ~ colorants which are excellent color matches for Red #2. The ; lO colorants of this inventlon can take on two forms. They can he monomeric, as have been all food colors approved for use I heretofore. Preferably, however, these new colors are in polymeric ~orm. As is disclosed ln`United States Patent

3,920,855, issued November 18, 1975 to Dawson et al~ ha~ing colors in polymeric ~orm can be advantageous. ~Jhen polymer~c colors are used in edibles, if the s~ze o~ the molecules of polymeric color exceeds a certain limit - usually a molecular size of from about laO0 to 2aoo Daltons ~ and if the color compounds do not break down and khus mainta~n this size, the polymeric colors are not absorbed through the walls of the ~as~
trointestinal tract. This means that ~hen such mater~als are eaten, they essent~ally pass dlrectly through the gastrointest~
inal tract. They are not taken into the body or its systemic circulation and thus any risk of poss~le systemic toxicity is-ellminated.

According to the invention, there is provided a compound of the formula O X

~ NH 3 ~/0 wherein Rl and R2 are independently selected rom the group of hydrogen, halos of atomic number g through 53, inclusive, lower alkyls and lower alkoxies of from l to 3 carbon atoms, nitros, and sulfonates and wherein X
is a halo of atomic number 17J through 53 inclusive or -NR3R~, wherein R3 and R4 are each independently hydrogen, lower alkyl of 1 to 4 carbon atoms or lower alkyl sulfonate of l to 4 carbon atoms.
Preferred colors of this invention are those in which R3 is hydrogen and R~ is hydrogen, alkyl or alkyl sulfonate.
This application is a divisional of our copending application Serial No. 293J227~ filed December 16, 1977, which relates to polymeric ; colorants having the formula \ / n wherein Rl and R are independently selected from the group of hydrogen, halos of atomic number 9 througk 53 inclusiveJ lower alkyls and lower alkoxies of from 1 to 3 carbon atoms, nitro, and~ sui~onate; R3 is hydrogen or a lower alkyl oE 1 to 3 carbon atoms, B is an organic polymeric backbone attached to N by a covalent bond and characterized as having essentially no crosslinks and containing only covalent bonds stable under the acidic, basic and enzymatic conditions o:E the mammalian gastrointestinal tract; and n is a number from 10 to 4000.

The remaining three positions on khe pendant non-fused aromatic ring to which Rl and R2 are co~alently bonded carry hydrogens. Rl and R2 preferably are separately attached to the ring at the 2, 4 or 6 positions. Preferably, ~ Rl is hydrogen and R2 is selected from the class of sub-3 stituents set forth hereinabove. More preferably, Rl is ~ hydrogen and R2 is hydrogen, chIoro or methoxy.
s~ .
' In a most preferred color Rl and R2 are both ;, hydrogen. This is an excellent red. Surprisingly, the presence of the diverse range of other Rl and R2 substituents, varying from strongly electron withdrawing nitro groups to strongly electron donating alkoxy groups makes only minor differences in the shade of these colors. A group of pre-ferred colors having a single nonhydrogen substituent on the nonfused ring is shown in Table I.
' `~ TABLE I
- . _ . : .
5ubstituent Rin~ Position Cl 2 or 4 Br 2 or 4 SO ~ M+ 4 NO2 2 or 4 _o-CH3 2 or 4 C2~5 2 or 4 Preferred backbones in the polymeric colors are carbon~oxygen ether backbones and essentially linear alkyl carbon-carbon backbones containing pendant primary and lower alkyl secondary amines in acetylated or unacetylated form, with or without additional covalently attached pendant groups such as sulfonates, phosphonates, carboxyls and the like.
Examples of these preferred backbones and the resulting polymeric colors are given in Table II.

2~

~ABLE II
Back~one Polymeric Color -- _.
polyvinylamine ~CH - CH2 ~ EI - CH2t NH N~I2 1. *
Chrom.
.~ n = 10 ~o 4000, preferab].y 100-2000 ~ m = 0.3 to 5n .

S polyvinylamine ~C~-CH2~CH-CH2t with acetylated l~ n¦ m residual amines NH N~c Chrom~

copoly(vinylamine/ ~&H-CH2~H-CH2~CH~CH2t vinylsulfonate) ~ n ~ P ¦ m (sho~ in sodium fo~n) NH SO3+Na NH2 : (other alkaline metals 1.
will work) Chrom.
~amine can be l. to 3 caxbon N-alkyl amine n ~ 10 to 2000 as well) m = 0.3 to 5n p ~ 0.3 to 2 ~n~m) .

copoly(vi~ylamine~vinyl ~CH-CH~CH-CH2~CE-CH2~
sulfonate) with acetylated ¦ n t - P 1 m residual amines. INH SO3 ~Na N~IAc Chrom.

poly N methylvinylamine ~cH-c~2)(cH-cH2t (other n-lower alkyl ~~ n I m amines can be used as N-CH3 N-CE3 well) ~' Chrom.
., ~ Chr~m. equals ' .
~a-~ ' ~
2~2~

P~176 T~BLE II (Cont'd) Backbone Polymeric Color copoly(vinylamine/
~ acrylic acid) tCH-CI~H~C~CH-CH~
(amines can be ¦ n ¦ m ¦ P
acetylated as well) NH NH2 COOH
Chrom.

.
sulfonated polyvinylamine ~CH-CH2 ~ H CH2~- fH-C~I2)p N-methylvinylamine ~R NR NR
or the like I J
ChromO . H ~Q3~ Na R = lower alkyl of l to 3 carbons or hydrogen (secondary alkyl and ` 15 primary amines can be acetyl~ted) aminated poly(epichloro- -~ÇH-CH~-o~ 4~H CH2 O~ CH-CH~-O) hydrin) (with added l n ~ m I ~ P
sulfamates ~H ~H~ ~H
~- ~hxom. ~O3'' ~Na .. .

. .
aminated and acetylated poly(epichlorohydrin) ~CIH-CH~-O)n (~H~CH2-O~m NH ~HAc lhromr Among backbones~ polyvinylamine and copoly~vinylamine/
vinylsul~onate), either acetylated or unacetylated, are pre~
ferred. These preferred backbones preferably have molecular weights o~ about 10,000 to about 150,000 Daltons and, in the case of the copolymer, an amine to sulfonate ratio of from 1:1 to 3:1O A polyvinylamine ~leeting this weight range has from about 200 to about 3000 units, a copolymer -- from about 60 to about 1800 amine unitsO The choice among back-bones often depends upon the degree of water solubility required of the final polymer colorant product. Polar groups such as carboxyls, phosphonates and especially sulonat~s are required in the pol~meric colorant to impart good water solu-bility properties. ~hen the color unit itself contains sul-fonates, i.e., when Rl and/or R2 axe sulfonates or alkyl sul-fonates, it-is not necessary to have these polar groups attached to the backbone as wellO When the color unit does not contain sulonate Rlls or R2's, good water solubilities, i.e., solubility in p~ 7 room temperature water of at least 1000 ppm, are achiPved only when a backbone containing polar groups -- such as the 29 copolymer backbones -- is employed.

The colors of this invention may be prepared by the following two routes. These routes are presented as exemplaxy methods and are not to be construed as limiting the scope of this invention.

The first route begins with l~amino-2-methyl-4-bromo-anthraquinone, a material marketed by Sandoz Color and Chemical ~ r~
- ~ under the tradc~e AMBAX, or made as in Example I.

~ C1~3 r 2.~
~-176 This material is reacted with a benzylic acid chloride~

CH2-COCl ~ 2 . ..

corresponding to the nonfused pendant aromatic ring desired in the colorant as follows:
fl Br CH2 - COCl S ~ C~3+

. ~ .

~ a3 .:_ , Y

~2 ~1 , This reaction is carried out in li~uid pha~e in a reactior-solvent. Suitable solvents include aprotic organic liqul~s especially cyclic and acyclic olefinically saturated aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, hexane, cyclohexane, heptane, C6-Cg hydrocarbon mixed sol-vents, cyclic and acyclic ethers such as dimethoxyethane, P-~76 1,4 dioxane, diglyme, and the like~ This reaction is carried out at elevated temperatures such as from 50C to 150C with temperatures of ~rom 75C to 130C being preferred. In our work the atmospheric reflux temperature of the solvent has S been used. The reaction could be carried out under pressure to obtain higher temperatures if desiredO Reac ion time is inversely proportional to temperature. Reaction times of from a ~ew (3-5~ minutes to about 24 ~ours generally are employed. The following examples will aid in selecting times - and temperatures. At 50-80C, times of about 10-2~ hours are usually adequate~ At 110-115C, the re~ction appears complete in about 20-30 minutes with tiTnes of from 20 minutes to three hours being used; at 150C, 3 to 5 minutes are adequate. Generally, a slight molar excess of the 2cid halide is employed since it is the less expensive reactant. AMBAX/
acid halide ratios of 1:1 to 1:2.0 are generally preferred with ratio of 1:1.1 to 1:1.3 being most preferred.

This AMBAX addition product is then c~clized with baseO

CH ~OH ) ~ ~ CH + H~o - 3 - ~ 1 3 2~ ~I ~ C~ ~ H

R2 Rl !; R2 R

The base employed is not critical, any strong inorganic base such as NaOH, KOH or the like will work. From 0.5 to 2 equivalents ~basis colorant) of base may be used. This step is generally carried out at elevated temperatures such as 90C to 250C with temperatures of 90C to 200C being preferred. This step can immediately follow the acid halide addition step by adding base to the crude halide addition product and heating for from about five minutes to about 24 hours. At S0C 24 hours is a good reaction time, at 110-120C, 15 minutes to one hour are employed. At 175-200C, five minutes are employed. Otherwise, the halide addition product can be isolated by evaporation of solvent and crystallization and dissolved in fresh inert aprotic solvent such as those used for the addition and then treated with base. This more complicated method offers some yield advan~ages. Both methods yield the new colors O Br C~13 ~<~ ~
R2 Rl wherein Rl and R2 are as already defined. It will be appreciated that the Br substituent is present principally because the AMBAX starting material is a bromo compound. Other halo leaving groups (i.e., Cl , I ) are essentially equivalent. The examples which follow will show the preparation of such equivalent materials. This color may be urther reacted at this stage to introduce or change the Rl and R2 substituen~s. Particularly, sulfonate Rl's or R2's may be introduced at this stage by liquid phase contact with 100% H2S04 at 80-150C for 0.5 to 2 hours, or by treatment with 15-30% oleum at room temperature (18C~ to 50C for 0.5 to 5 hours.
The color is next coupled to an amine. This may be a R3-N-R4 monomeric amine as has been defined or it may be an amine group-containing polymer backbone as has been described above in connection with the invention of the parent application Serial No. 293,227. In this step the amine displaces the halo leaving group on the anthraquinone ring as follows:

Backbone + ll CH3 Nl - R3 R2 Rl R4 or Ba~Gkbone ¦ CH3 + HBr NH

R2 Rl ~2~
! P 176 This step is carried out in liquid phase as well, generally in a water or mixed water/organic solvent and ~ase and with a copper catalyst. This amine displacement is an adaption of the classic Ullmann reactionO

Water, and water containing up to abou-t ~5~ of a water-miscible organic, such as an alkanol or glycol (methanol, ethanol, ethylene glycol and the like) 9 mono and dialkyl ethers cf ethylene glycols such as the materials marketed by Union Carbide undex the trademark Cellosolv~ , and liguid organic bases such as pyridine may be used a- solvent~ Water and water containing up to about 20~ pyridine are preferred solvents.
The copper catalyst useful for this coupling may be copper metal, a copper (preerably cuprousl salt or an oxide of copper, for example ~inely divided copper metal, Cu~C12, and Cu2O suppoxted on carbon black. A catalytically effeative amount of catalyst is employed. Such an amount oan ranye ~rom about 0.0I to about 0.5 equivalents (preferanly 0.05 to 0.4 ; equivalents) o copper per equivalent of reactive amine.
Base, especially a strong inorganic base such as NaOH or KOEI~
should be present in an amount in excess of the molar amount of chromophore being coupled. Preferably ~rom 0.5 to 5 equivalents ~basis-frQe amine) of base is present with amounts from 1 to 3 (especially about 2) equivalents giving best results. The coupling is effected at a temperature o~ from about 60C to about 200C, prefQrab]y 80C to about 150C, and a tim~ of from about 0.2 hoursto about 24 hours, preferably 0.5 hours to about 8 hours, dependlng upon the temperature.

-lS-This yields the coupled product R4 or ~ackbone O N-R
;` ~ ~
ll N~ 3 R2 Rl as a crude reaction mixture~ The desired product can be freed of catalyst and impurities as desired. It may also be subjected to post treatments such as acetylation or the like as desired.
The second preparative route is similar to the first. rrhe acid chloride is attached to the AMBAX in the same way. Then, however, instead of separately cyclizing the AMBAX addition product, the uncyclized addition product is coupled to the amine or amine-containing backbone with the conditions of the coupling also effecting cyclization. Economies of produc-tion may favor the second route, but yields and product purities are often somewhat higher with the longer process.
The products of this invention and that of the par~nt application ;~; are excellent red colors. Those containing polar groups in their chromo-~ phores or attached to their amines (i.e., when R4 or the backbone contains :
;' ~' a polar group) are water soluble. As solutions they present clear, brigh-t intense reds. When added in coloring amounts such as from 10 to 10,000 ppm wt, they bond to and dye fibers and other substrates.
The polymeric dyes present especially advantageous utilities as colorants for edibles. The polymer compounds wherein Rl and R2 are hydrogen are especially useful in this application as these materials are virtually a direct match in hue for now-banned Red #2. Ihe other polymeric members of this colorant family are good reds for foods~ blending well with yellows and blues to give the range of oranges, reds and grapes desired by the food industry.
For food use the colorants may be polymeric and of molecular weight above about 1000 Daltons, preferably above about 2000 Daltons so as to preclude their absorption through the walls o the G.I. tract.
In edible applications the polymeric colors are dissolved in beverages and syrups, dry mixed into powdered drink mix and cake mix, and otherwise conventionally admixed with foods~ beverages, pharmaceuticals and cosmetics. The amount of color used in these applications will range between about 10 ppm wt and about 1000 ppm wt, basis inished foocl, beverage, or pharmaceutical. Cosmetic uses may requ:ire higher use levels.

3~

The invention is urther illustrated by the ollowin~ ~xarnples, some of which are included for re~erence purposes. These are intended solely to exemplify the invention and are not to be construed as limiting the scope of the inven~ion which is instead defined solely by the appended claims.

' 2~L
~-176 EX~MPLE I

Preparation of ~ H

wherein ~l and R2-are hydrogen.
, :
A. l-amino-2-methylanthraquinone (~0 g) is slurried wi.th 1500 ml of HOAc in a 5-liter ~lask. The tempera~ure is raised to 40C. Neat bromine (405 g) .is added over 2-l/2 houxs wikh stirring at ~0-50Co The mixture is stirred for 20 addikiunal minutes and filt~red. The solids so recovered are washed with HOAc and water and sucked dry with an aspirator and tran~:Eerred.
to a reaction flask along with 150 g of NaHSO3 and~l.5 li.ters o water. The mixture is gradually heated to 90C (over two hours) with stirring to give l-amino-2~methyl~~-bromoant.hra~
quinone as a solid which is recovered frorn the reaction mixture by filtration in 90% yield, rinsed with water and dried over-night at 155C and 1 r~m Hg absolute vacu~m.

It will be appreciated that chlorine or iodine could be substituted for bromine in this reaction if desired.

' P~17~

B. ~ ~ ~Cl C6H~CH3 ~ ~c~3 Wt used 15.8 g ~.5 ~ 21.7 g (theory) Moles used 0.050 0O055 Ratio l.0 lol A 250 ml flask e~uipped with ov~xhead stirrer, water-cooled condenser, and ~r inlei is charged with the bromoanthraquinone of part A and 120 ml of toluene. To the red slurry is added the phenylacetyl chloride and the mixture is heated to reflux.
The xea~tion is followed by thin~layer ~hromatography. After one hour most of the starting material is gone. After three hours, the reaction appears to be over, althouyh some starting ' material still remains.
After 3.5 hours total refluxing, the reaction i~ cooled to ca~ 80 and filtered. The dark yellow filtrate is con-centrated to ca. 30 ml on a rotor~ evaporator and co~led~ A
large amount of dar~ solid forms which is isolated and washed with ether unti~ a yellow (dark) solid is obtained. The solid is oven dried at 70Q, < 1 mm, for four hours ~o afford 1G .5 g ~57.6%) of yellow-green solid productO

. ~ f ' C ~'J:1~' CH3~\/OH ~J~
~3 AqO KO~I > ~ ~ ~ ~I3 .
Wt used 4.56 g 0.45 g 4.37 g (theory) Moles used lO.S mmole 800 mg - f.w~

, .~ A 100 ml 3-necked flask is equipped with water-cooled ~5 condenser, overhead stirrer, thermowell, and Ar inlet. The flask .is charged with the phenylacetyl product of Part B, and 30 ml methyl cellosolve. The conten~s are heated to 122 - and the KOH in 0.6 ml H20 is added drop~ise over o~le minute.
: The reaction is stirred at 120 for on~ hour.
The.reaction mixtuxe is cooled to about 5C. Isolation of a solid precipitate, followed by washing, affords 1.71 g (39~1%) of hright~ shining gold solid.
The darkl yellow filtrate is concentrated via rotary evaporator to dryness and the dark solid is recrystallized from 170 ml of HOAc to afford 2.3 g {52.6%) of a dull, golden colored powder. Total yield is 4.01 g (91.8%).

~ 9~ P-17~

EXAMæ~E II

Pxeparation of a monomeric colorant from the product o~

Example I NaO~

Aqueous ~ ~
CH3 + + NaO~ C~zCl2 ~ ~ ~3 . 5 ~ ~* used 1.:0 g O.306 g 7.2 ml of 1 ; Moles used 2.4 mmole 2.2 mmole 7~2 mequiv.
' ' ' .
A 25 ml flask is charged with the product of Example I, sulfo-propylamine, aqueous sodiu~ hydroxide, 3 7 6 ml H20, l.Z ml pyridine, and 40 mg cuprous chloride. The flask is equipped with a . lO magnetic stirrer, thermowell, and reflux conde.nser. ~fter flush-ing the system with argon and de-a~rating, the contents are heated to reflux ~95-100) for 3.3 hr. The reaction mix~uxe is then cool.ed to room temperature, diluted with dilute sodlum hydroxide solution, and carefully filtered to remove solids~
The solution is then concentrated to dryness under reduced pressurè, and the resultant solid dissolved back into wate.r.
The pure, monomeric dye can be isolated by preparative thin layer chromatography,-preparative high pressure liquid chromatograp.~y~
or by recrystallization.

-~2-EXAMPLE III

To 2304 g of acetamide ttechnical3 in a 1~ liter xeaction flask is added 62.2 ml o~ 6M aqueous sulfuric acid followed immediately by 661 g of acetaldehyde (99 ~). This mixture is stirred and ~eated until the internal temperature reaches 78C tll minutes) at which point the cléar solution spontaneously crystallizes, causing a temperature rise to 95C. The reaction product, ethy1idene-~is-acetamide, is ~
not separated. ~eating and stirring are ~continued for another five minutes to a temperàture of 107C and a mixture of 150 g calcium carbonate (precipitated chalk) and 150 g of Celite~
diatomaceous earth powder is added. A ~irst distilla~e fraction of water and acetamide is remo~ed. The remaininy materials are cracked at 35 mm Hg and 185~C. A fraction made up of vinylacetamide and acetamide is taken overhead, analyzed by NMR and ~ound to CGntain 720 g of vinylacetamide and 306 ~
of acet~mide. A portion of this pooled material is dissolved in isopropanol, cooled, and filtered to yield a stock solution:
This stock solution is analyzed and found to be 4.1 molar in vinylacetamideO

Into a five liter flask is added 505 ml ~272 g) of a . ; , .
vinylacetamide solution obtained by stripping isopropanol from 900 ml of the above stock solutio~ (containing 3.6g moles of ~inylacetamide)O ~IBN (15 g) in 1500 ml o~ water is added followed by 1279 g of 25% W sodium vinyls~lfonate in water (Research Organic Corporation) and a liter o water. This is two equivalents of sulfonate per three equivalents of vinyl-acetamide. Followiny deoxygenation, the mix~ure is heated to -~3-; ~ ~ ~ ~ P~17~

65C and there maintained with stirring ~or three hours~ This reaction mixture is then reduced to 2/3 volume, solid AIBN
is removed and the liquid added to eight gallons of isopropanol.
The copolymer precipitate is collected and ~ried in VaCtlUm to yield 865 g of solid copolvmer (MW 6~6 x 104). Whenever an experimental molecular weight is given in this specification, it is derived by gel permeation techniques. In the primary technique, a silanized porous glass support is used with a O.01 M LiBr in D~F eluent. Detection is by refractometer with standardization being based on suitable purchased poly(styxene) or poly~styrene sulfonatej standards.
. .
Into a two liter flask is added 863 g of t~e just-noted solid product, 2.5 liters of water and a liter of concentrated hydrochloric acid. The mixtur~ is refluxed ~99-110C) ~or about 24 hours and cooled, the solid precipitate is washed, and dissolved in three liters of 10~ NaOEI. This mixture is added to about 12 liters of methanol to give 400 g of ine solid copolymer precipitate~

323l EX ~ PLE IV

O Br H3 1 d~O/pyridLne Fo1~ic NH ~ vlnylsulfonate CU2C12' NaO~ c3lorant.
copol~mer (Example I) (~xample III) Wt. used 0.-958 g 0.500 g 0.~77 g Moles used 2.30 mmol ~.835 me~ 0.39 mg - f.w.

Ratio 0.60 1.0 0.20 equiv. Cu*
. .
A 50 ml two~necked flask is charged wit~l ~he copolymer, ~lI.5 ml l N MaOH, 1 ml o pyrid~ne and 4 ml H2O. The system is : de~aera~ed.... The polymer dissolves and the anthraquinone and 10Cu2C12 are added an~ the mixture is heated to 97~ Af~er 2 1~2 hr~ the mixture is cooled and diluted with 40 ml water at pH 11.
~ he diluted mixture is filtered to afford 100 ml of a red solution. The solution is ultrafiltered using 10~ pyri.dine in water at pH 11 and later pH 7 water as mak.eup.
l~The red solution i5 l~ophîlized to afford 0.850 g of red solid which is determined to be P~17 6 ~CH-CH2) A ~CH_CH2~H-CH~

IH

~herein A ~ B ~ D equals about 900.
A -- ~ 180 B ~ _, 360 . D ~ ~ 360.

,. . .

2~23L

EXAMPLE V
Preparation o~ an acetylated version of the colorant of Example IV.
The product of Example IV (255 mg) is dissol~ed in 12 ml of water and cooled to 5~O Fifty percent NaOH is added to pH 12 followed by 0.2 g of ace-tic anhydride. The pH adjustment to 12 and 2cetic anhydride addition are repeated twice. The red solu-tion is fil~ered, ultrafiltered and lyophilized to yield a soli~ product of Example IV whexein about 95% of the free backbone amines are converted to HN-~O groups. This red ~olid is ~n excell~nt colorant. It is very good replacement for existing red food colors. Virtually identical colors would result when the ~ollowing changes are made.
1. The backbone amine to sulon~te ratio is varied from 1.5:1 to ~.0:1.
2. The backbone peak molecular weight is varied froM
35,000 to 80,0~0.
3. The fraction of total bac]sbone amines substituted with chromophores is variéd from 25% to 40%.

4. The degree of acetyla~ion is varied between 80% to 98% of the total amines.

~-~7~

~2~Zl P- L75 E~XAMPLÆ VI
_ ._ Preparation of O Br ~ ~ ~NH

Cl 1~0) + SOC12 ~ I : 24 hr ~
: ` COO~ ~ OCl Wt. used 17.06 y 11.90 g 18.9 y (theory) M~les used 0.100 0.100 A 50 ml flask is charged with the oryanic acid and the SOC12. A sinyle boiling chip is added and the flask fitted with air condenser and drying tube. Heating in a 45 oil bath is begun. The reaction is cooled after 23 hours.

To the solution is added 5 ml of benzene. Volatlle material is pumped o~f at room temperature at 0.5 mm Hg.
The product is then dis-tilled through a short path vacuum distillation apparatus as a water white product, b.p. 63-64 at 0.10 mm Hy. The yield of distilled product is 12.3 g (65%).

~2S~

O Br toluene ~

l3 ~ ~ ~ C~3 Wt. used 15~8 g 10.87 g 120 ml 23.4 g (theory) ~oles used 0.050 0.0575 Ratio 1.0 1.15 The procedure of Example II, Part B, is repeated using the above materials to afford the abo~e product.
C.

O Br O Br `CH 3 KO~I ~ ~ c~l3 ~ ~ Cl~ ~

Wt. used 9.85 g 0.88 g 9.46 g (theory) Moles used 0.021 0.0157 g Ratio 1.0 0.75 rme product of P æ t B and 60 ml of Cellosolve are added to 1 250 ml flask. r~ne slurry is heated to 123 . The KOH is dissolved in 1.0 ml H2O
and added over one minute. The reaction is cooled afber heating at 115 for 35 minutes. The mixture is allowed to cool slowly to ro~m temperature and then oooled to 5 &. A solid precipitate is isolated and washed to afford 3.32 g of glittering, ~rowni~sh/golden crystals.

'1~

The dark filtrate is concentrated to dryness and the resul-tant dark solid recrystallized frcm 675 ml boiling HOAc. The greenish~yellcw needles are isolated and washed. Drying at 85, < 1 mm for four hours affords 3.8 g of a golden solid.

r ~.

EXAMPI.E VII
If the preparation of Example VI is repeated using the chloro or iodo anthraquinones shown in Example I in place of the brorno anthraquinone, the correspondin~ chloro or iodo products would result.
~ Similaxly, use o~ the 2f 4-dîchloro, the 2-chloro, the : bromo or the iodo equivalents of the 4~chloro acid in place of the 4-chloro acid in step A of E~ample VI would result in the 2,4-dichloro, the 2-chloro, the bromo or the iodo-substituted products.
.

-31~

' ~2~1 P~176 EXAMPLE VIII_ Attachment of the pr~duct of Example VI to the polymer of Example III.

.: .

~opolymer pyridine/H2o Polymeric of III CU2C12' NaOH Colorant . ,~
Cl W~. used 1.037 g ~.500 0~077 g ~u2C12 Mm~les used 2,30 3.835 m~q 0039 n~ of Cu2Cl~
11.5 mmol~ Orr ~atio 0.6 1.0 0.2 equiv Cu~
3.0 Q~UiV. o~r . ..
The copol~ner is dissolved in 11.5 ml lN NaOH and 4 mI H20 The solution is de~aerated (3 tirnes, ~7ith Ar) and the anthra-pyridon~ derivative, Cu2Cl~, and pyridine ~1.5 ml) are added.

The reaction i5 stirred at 96-97 for two hours and ~0 minutes, then cooled and diluted with dilute aqueous sodium hydroxideO

The dilute mixture i5 filtered to afford 115 ml of a dar}c red dye solution. ITltrafiltr~tion is ca~ried out with 10%
pyridine--pH 11 waterO Then, the product is divided into two portions.
One psrtion is acetylated and the other is lyophilized to afford 490 mg of red solid in accord with E~ample V~

(- ~
~ 2~
,, The unacetylated product has the ormula C~ H~CH2 ) m ~H-C~I
H NH2SO3Na+

n ~ m ~ P = ~900 n - 180 ~ ~ NH m - 360 Cl p ~ -360 The acetylated version differ~ only in that the residual NH~'s on the backbone are present ~5 NHAc~so Both are excellent red colorants...
Substitution of the products of Example VII for the product o~ EY.ample VI as feedstock for this Example would yield their poly.mer product counterparts.

. .

~-176 EXAMPLE IX
Preparation of ~C~:13 ~ "NH

NH + o The product o E ample I, ~

0.6 g and ~.4 g of 20% olewm are stirred together at room ., temperature. After one-hal~ hour, it appears that reaction ha~
occurred. The stirring is continued for a total of five hours.
The reaction mixture is poured over ice and water and a solid precipitate forms and is collected. The solid is dissolved in a liter of 2 M NEl~OX, filtered and the solution is evaporated to dryness. The solid which results is extracted with methanol.
The methanol i~ evaporated to afford 0.775 g of ~he desired sulfonate product.

3~-~Z~32~

EX~MPJ~E X
Formation of a homopolymeric polyamlnoethylene backbone for coupl-ing colors into polymeric form A red~brown solution of 460 g of vinylaoetamide, 557 y acetamide, and 123 g ethylidene-bis-a oe ta~ide, (one-half of five combined vinyl-acetamide preparations essentially in accord with Example III) in 570 ml methanol is filtered through 250 g of Pmberlite ~IRC-50 ion exchange resin over an eight-hour period. The column is rinsed with 1000 ml methanol. m e combined column eluent is stripped to its original volume of 1,667 ml, treated with 7.75 g of AI~N polymerization catalyst (1 mole %), deoxygenated, and stirred under Argon at 65 & for 15 hours to polymerize. Solid polymer is precipitated from the resulting very thick solution by addition to 15 liters of acetone. m e polymer is collected by filtration, washed with aoe-tone and dried in a vacuum oven (80 &) for two days to afford 459 g of crude poly(vinylacetamide) contaminated with aoetamide as a yellow, s~igranular solid having molecular weight of 2 x 104 as determined by Gel Permeation Chromatographyl using dimethylformamide as eluenk and polystyrene as stand-ards.
~e crude poly(vinylaoe tamide) (459 g) is dissolved in 1000 ml water with heating. Concentrated hydrochloric acid (1000 ml) is added and the resulting dark brown soluticn is stirred and heated at a gentle reflux ~97-106C) for 19 hours. A precipitate forms and is redissolved by addition of 200 ml water. Reflux is co~tinued and over the next eight hours 3~

1000 ml water is added in several portions to maintain solu-bility of the polymer D After a total of 27 hours at re~lux, the polymer is preclpi-tated by the addition of 1000 ml con-centrated hydrochloric acid. The mixt~lre i5 cooled to 18C
and the thick polymeric gum isolated by decantation and dried under vacuum at 50-75C with occasional p lverizaticn for 40 hours to give 332 g of poly(vinylamine hydrochloride) as a brown granular solid i77~ yield from vinylacetamide, 59%
from acetaldehyde)~

.

.. .

-3~-P~176 EXAMPLE XI
Formation of a polymeric colorant from the anthraquinone product of Example IX and the pol~mer product of Example X.
Following the procedures of Examples IY, 0.754 g of the anthraquinone product of Example IX is coupled to 0.200 g or the polyaminoethylene product of Example XO Copper catalyst (0.021 g) and NaOH ~three equivalents hasis polymer) are used.
The reaction is carried out for one houx at 97C. The reacti~n mixture is diluted and filtered and ultrafiltered. The retentate of the ultrafiltration is divided into two portions. One i5 lyophilized to afford the following product H-C~2 ~ ~ CH~)n NH NH
(~
~ ~ ~ m ~ 260 .. ~CH3 n ~ 200 , ~IH
Na~ O3S ~ ~

The other portion is acetylated in accord with th~ general procedure of Example V to give a product wherein the residual lS backbone amines are acetylatedq In this and in all acetylations in this disclosure, conversion of amines to amides is usually not quantitative. Usual conversions are 80~8% of the amine being converted.

f ~ ~z~

EXA~?LE XI I

NO C 2 5 hrs Q35 ~ ~2 02H COCl Wt. Used 18.11 g 12.0 lg.9 (theory) Moles Used 0.100 OolOl The reagents are weighed into a flask and allowed to stand at room temperature (~ 21) overnight. ~ stirring bar is added and the reaction driven to completion by war~in~
at 35 until no solid is visible (.five additional hours). To the red solution i5 added 5 mls ben~ene and -the volatile material is removed with vacuum.

B. The 2-nitro acid chloride of Part A is reacted l~ith ~MBAX
and the ring is closed to give the product ~ 2 The general reactions of Example I are used. The reaction of this acid chloride with ~MB~X is more facile and requires only three hours at re~lux.

~J~ - f ~2~21 . P-17 C. - ~he product of Paxt B is attached to the polymer of Example III using the method of Example IV~ This product is divided into two portivns r one of which is acetylated.

. .

~39-~2~ 2~

E~AMPLE ~

A. OCH3 OCH3 ~3 + SOC12 r240hrten p. ~ [~
~ COOH COCl Wt. Used 16.16 g- 11.90 g18.4 g (theory) Moles Used 0.100 0.100 A flask is charged with the carboxylic acid and thionyl chloride and allowed to stand at room temperature with occasional swirling for 24 hours. The endothermic reaction begins immediately and proceeds at a very good rate, generating an orange solution.

After 24 hours, nearly all gas evolution has ceased.
Six ml benzene is added and the volatile material i5 removed with vacuu~. The product is purified hy distillation.

B. A flask is charged wi-th 15.8 g AMBAX and 115 ml toluene. Then r the acid chloride, 10:1 g, is added. The lS red slurry is heated to reflux for 2.0 hours.

The hot mixture is filtered and a black res;due washed with three portions of hot toluene. The toluene is stripped off afording a solid ~hich is washed with ether.
The product is dried overnight at 70, ~ 1 mm to afford 19.48 g of dull green powder.

~ 9~1 P-17~

This product i5 treated with base i~- accord with the procedures of Example 1, Part C, to 1~ield ~ ~ CH

C. q'he prod~ct o~ Part B i~ coupled ~o the polymer o~
Example III to afford a polymeric dye o~ the structure . ~ , ~CII - CH2-~C~I - CEI2-~H - CH2t---m = ~360 H3C ~ ~-' p = ~360 :

~Z~l ~-176 EXP~PLE XIV

This exa~.ple illustrates an alterative preparation of the ;

compound of this invention.

Br ~r diglY~e~ ~ 0 1. 100-113 ~ ~

C~3 ~ ~ c~3 Wt. used 1.897 kg 1.113 kg 370 g Moles used 6.0 ~ 702 r Ratio 1.0 1.2 .~ .

; - A~22~1iter resin };ettle iS ch~ryed ~7ith the a~thraqu~none and 13.8 liter of dig].yme. The reactox is fitted with a ~-necked s~ 10 head which is equipped ~7ith overhead stirrer, thermocouple, argon outl~t~reflux conclenser, and an argon inlet to sweep the system.
~ The reaction mixture is then heated to 111-113 and the acid ti chloride is added quickly. After 30 minutes at 111~117~ a p~
probe is inserted into the reaction mixture in place of the 1~ argon inlet. A solution of 370 g of potassi~n hydroxide in 346 ml of water is then carefully added portionwise while th~
pH of the system i5 monitored. By the end of the hydroxide addition, the pH meter should give a readlng of ca. 10.3.
Product soon begins to drop out and after a total reaction time of 90 minutes ~including 30 minUte acetylation time) the heating mantle is turned of.

-~2-,, Z~3Z~L

Next the system is cooled re~lu~ively by gradually reducin~
the internal pressure using a water aspirator. When the pressure reaches 27-inch ~Ig of vacu~n, the internal temperature is 55.
The vacuum is released and 3 liter or methanol are added. The resultant slurry is then filtered via a cer~nic filter~ng crcck and sucked dry. The filter cake is washed with one 4~1iter portion of methanol, sucked dry at a large watex aspirator, and finall~ vacuum oven dried overnight at 80, 0.4 mm Hg. The yield of yellow--green product is 1.904 kg (76~)o .

- .

, .

.

EXAMPLE XV

This example shows a one-step closing and attachment to a backbone.

Br Copolymer H Op~ridine Polymeric of Example 2 ~ C~lorant H

~2 Wt. Used ~1.0 g 2.4 g 0.076 y Moles Uscd 2.3 mmo1e 3.S4 meq 0.39 mmole CU;~C12 Ratio 0.6 1.0 n. 20 e~. Cu~

, .
.
A 25 ml flask.is char~ed with the anthra~uinone derivative, the copolymer backbone, 11.5 mls lN NaOH solution, 1.3 mls pyridine, and the cuprous chloriae. The ~lask is equipped ~lith reflux condenser, magnetic stirrer, and thermo-couplc. The s~stem is then de-aerated and ~lushed with argon.
The reaction mixture next is stirred and heated at ~6-100C

for 3.5 hours, a~ter which time the reaction mixture is cooled, diluted, filtered, and ultra~iltered~ The resultant dye is then acetylclted as in ~xample V and ~orked up as in E~:ample ~ to afford a red dye which is indistinyuishable from the dye prepared accordin~ to Example V.

-~4-

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A compound of the formula wherein R1 and R2 are independently selected from the group of hydrogen, halos of atomic number 9 through 53 inclusive, lower alkyls and lower alkoxies of from 1 to 3 carbon atoms, nitros, and sulfonates and wherein X is a halo of atomic number 17, through 53 inclusive or -NR3R4, wherein R3 and R4 are each independently hydrogen, lower alkyl of 1 to 4 carbon atoms or lower alkyl sulfonate of 1 to 4 carbon atoms.

2. A monomeric colorant of the formula wherein R1 and R2 are independently selected from the group consisting of hydrogen, halos of atomic number 9 through 53, inclusve, lower alkyls and lower alkoxies of from 1 to 3 carbon atoms, nitros, and sulfonates and wherein R3 and R4 independently are selected from the group consisting of hydrogen, lower alkyls of from 1 to 4 carbon atoms and lower alkyl sulfonates of from 1 to 4 carbon atoms.

3. A compound according to claim 2, wherein R3 is hydrogen and R4 is hydrogen, alkyl or alkyl sulfonate.