Benzisothiazolazo, diaminopyridine dyes

Abstract

A compound having the formula: ##STR1## where X is hydrogen, chlorine or bromine, B is hydrogen, methyl, ethyl or propyl, and one of the radicals R.sup.1 or R.sup.2 is phenyl which is unsubtituted or mono- or poly-substituted by chlorine, methyl, ethyl, t-butyl, phenoxy, methoxy, ethoxy, propoxy or butoxy, and the other is C.sub.2 -C.sub.8 -alkyl which is unsubstituted or substituted by C.sub.1 -C.sub.8 -alkoxy or phenyl, or is allyl, cyclopentyl, cyclohexyl, methylcyclohexyl, ##STR2## The compounds of formula (I) are used as dyes, preferably for cellulose and cellulose-containing fabrics.

Description

SUMMARY OF THE INVENTION

Azo dye having either 2-arylamino-5-cyano-6-alkylamino- or 2-alkylamino-5-cyano-6-arylamino-pyridine as coupling component general formula I ##STR3## where X is hydrogen, chlorine or bromine, B is hydrogen, methyl, ethyl or propyl, and one of the radicals R.sup.1 or R.sup.2 is phenyl which is unsubstituted or mono- or poly-substituted by chlorine, methyl, ethyl, t-butyl, phenoxy, methoxy, ethoxy, propoxy or butoxy, and the other is C.sub.2 -C.sub.8 -alkyl which is unsubstituted or substituted by C.sub.1 -C.sub.8 -alkoxy or phenyl, or is allyl, cyclopentyl, cyclohexyl, methylcyclohexyl, ##STR4##

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Specific examples of alkyl radicals R.sup.1 and R.sup.2 are C.sub.2 H.sub.5, n--C.sub.3 H.sub.7, i--C.sub.3 H.sub.7, n-- or i--C.sub.4 H.sub.9, n-- or i--C.sub.5 H.sub.11, n-- or i--C.sub.6 H.sub.13, n-- or i--C.sub.7 H.sub.15, n-- or i--C.sub.8 H.sub.17, C.sub.2 H.sub.4 OCH.sub.3, C.sub.2 H.sub.4 OC.sub.2 H.sub.5, C.sub.2 H.sub.4 OC.sub.3 H.sub.7, C.sub.2 H.sub.4 OC.sub.4 H.sub.9, (CH.sub.2).sub.3 OCH.sub.3, C.sub.2 H.sub.4 OCH(CH.sub.3).sub.2, (CH.sub.2).sub.3 OC.sub.2 H.sub.5, (CH.sub.2).sub.3 OC.sub.3 H.sub.7, (CH.sub.2).sub.3 OC.sub.4 H.sub.9, (CH.sub.2).sub.3 OC.sub.6 H.sub.13, (CH.sub.2).sub.3 OC.sub.8 H.sub.17, ##STR5##

The compounds of the formula I can be prepared by reacting a diazo compound of an amine of the formula ##STR6## with a coupling component of the formula ##STR7## in a conventional manner. Details may be found in the Examples, in which parts and percentages, unless indicated otherwise, are by weight.

The compounds of the formula I are preferably used for fixative printing (known under the tradename DYBLN, cf. eg. German Pat. No. 1,811,796 or U.S. Pat. No. 3,706,525), in which tone-on-tone dyeings can be produced on mixtures of cellulose fibers and polyester. Blue to black dyeings with very good fastness characteristics in comparison with conventional dyes, in particular lightfastness and wetfastness, and also a high stability to live steam, are obtained.

Particularly important compounds are those of the formula I a ##STR8## where R.sup.1 and R.sup.2 have the above meanings, but R.sup.2 is preferably ##STR9## and R.sup.1 is preferably ##STR10## always in combination with an unsubstituted or substituted alkyl radical of the type defined, and alkyl is methyl, ethyl or t-butyl.

Examples of preferred unsubstituted or substituted radicals R.sup.1 and R.sup.2 are --CH(CH.sub.3).sub.2, ##STR11##

Combinations where R.sup.1 is C.sub.6 H.sub.5 and R.sup.2 is ##STR12## are also preferred.

EXAMPLE 1

19.6 parts of the diazo component of the formula ##STR13## are prepared and diazotized with nitrosylsulfuric acid, by the process described in German Pat. No. 2,412,975. The finished diazonium salt solution is then run into a suspension of 31.1 parts of the coupling component of the formula ##STR14## in a mixture of 400 parts of water and 900 parts of ice. About 30% strength sodium formate solution is added to the coupling mixture, until the pH of the suspension has risen to 0.3-0.7, during which time the temperature is kept at below +5.degree. C. by addition of ice. The coupling has ended after about 30 minutes, and the precipitated dye is isolated, washed salt-free and dried, in a conventional manner. 49 parts of a bluish black powder of the formula ##STR15## are obtained. The dye melts at from 225.degree. C. to 230.degree. C. and dyes cotton, polyester and polyester/cotton union fabric in lightfast reddish blue to navy shades.

If, instead of the above coupling component, the coupling component mixture formed when 2,6-dichloro-3-cyano-4-methylpyridine is reacted first with 2-methoxyethylamine and then with 2-methoxyaniline, as described in German Pat. No. 2,260,827, is used, the corresponding amount of a dye mixture is obtained which, in addition to the above dye, contains a minor amount of the dye of the formula ##STR16## The mixture melts at from 185.degree. to 229.degree. C.,

The absorption maximum of a solution of the dye in dimethylformamide (about 10 mg/l) is 589.5 nm.

The dye mixture dyes or prints cotton, polyester and polyester/cotton union fabric in highly lightfast clear blue to navy hues at a slightly lower temperature than the pure dyes. The dyeings or prints have good wetfastness, even when the hues are deep, and they are also stable to hot steam.

An example of a suitable dyeing method is the procedure described in European Pat. No. 0,012,935, and an example of a suitable printing method is that of German Pat. No. 1,811,796.

EXAMPLE 2

27.5 parts of the diazo component of the formula ##STR17## are stirred into 200 parts of 96-98% strength sulfuric acid at from 10.degree. to 15.degree. C. The mixture is then cooled to 0.degree.-10.degree. C., and a mixture of 100 parts by volume of glacial acetic acid and 17 parts of propionic acid is added dropwise at this temperature. 33 parts of 42-44% strength nitrosylsulfuric acid solution is then added dropwise at 0.degree.-4.degree. C. in the course of from 20 to 30 minutes, with cooling. The diazotization mixture is subsequently stirred at from 0.degree. to 4.degree. C. for from 31/2 to 4 hours, and is then run, with stirring, into a suspension of 31.1 parts of the mixture of coupling components of the formulae ##STR18## which is described in Example 1, in a mixture of 400 parts of water and 900 parts of ice.

After the diazonium salt solution has been added, the pH of the coupling mixture is increased to 0.5-10 with approximately 30% strength sodium formate solution, during which the temperature is kept at from -3.degree. to +5.degree. C. by addition of ice.

The reacted coupling mixture is heated to 85.degree. C. with steam and is kept at from 85.degree. to 95.degree. C. for 15-30 minutes, and the precipitated dye is washed salt-free in a conventional manner and dried to give 57 parts of a black powder of the formulae ##STR19## The mixing ratio of the dyes is the same as that of the coupling components used.

The dye mixture is soluble in dimethylformamide, giving a blue solution, and dyes or prints cotton, polyester or polyester/cotton union fabric in blue to navy hues. The resulting dyeings or prints have good lightfastness and wetfastness.

EXAMPLE 3

19.6 parts of the diazo component of the formula ##STR20## are prepared and diazotized by the process described in German Pat. No. 2,412,975. The diazonium salt solution is then run into a suspension of a mixture of 20.6 parts of the coupling component of the formula ##STR21## and 9.8 parts of the coupling component of the formula ##STR22## (which, because of the method of synthesis, each contain a relatively small amount of the 2,6-isomeric coupling component) in a mixture of 400 parts of water and 900 parts of ice. The individual coupling components are prepared from 2,6-dichloro-3-cyano-4-methylpyridine by a method similar to that described in German Pat. No. 2,260,827, by reacting the heterocyclic compound first with the aliphatic amine and then, in a second step, with the aromatic amine.

The coupling is brought to completion by a procedure similar to that described in Example 1, and the dye is worked up in a conventional manner. 47.5 parts of dye powder are isolated. A dye mixture is obtained, containing individual components of the formulae ##STR23## and relatively small amounts of ##STR24##

The dye mixture melts in the range from 185.degree. to 198.degree. C. and its powder is bluish black and dissolves in dimethylformamide giving a blue solution.

Pale dyeings or prints on polyester, cotton or polyester/cotton union fabrics are reddish blue, whilst deeper dyeings are clear navy.

The dye mixture dyes polyester and cotton with a good matching of hue. The dyeings have good fastness characteristics in use.

The dyes listed in the Tables can be prepared by a procedure similar to that described in the Examples. Where two hues are given for dyeings or prints, the first refers to a lighter dyeing (or print) using about 0.2-0.4% of dye, and the second refers to a dyeing (or print) using not less than 0.8% of dye.

TABLE 1__________________________________________________________________________ ##STR25##No. R.sup.1 R.sup.2 R.sup.3 Hue__________________________________________________________________________ 4 ##STR26## C.sub.6 H.sub.5 CH.sub.3 reddish blue navy 5 ##STR27## " " " 6 ##STR28## " " " 7 ##STR29## " " " 8 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " " 9 ##STR30## " " "10 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "11 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "12 ##STR31## " " "13 C.sub.3 H.sub.6 OCH.sub.3 " " "14 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "15 ##STR32## " " "16 ##STR33## " " "17 ##STR34## " " "18 ##STR35## ##STR36## " "19 ##STR37## " " "20 ##STR38## " " "21 ##STR39## " " "22 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " "23 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "24 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "25 ##STR40## " " "26 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy27 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "28 ##STR41## " " "29 ##STR42## ##STR43## " "30 C.sub.2 H.sub.4 OCH.sub.3 " " "31 C.sub.3 H.sub.6 OCH.sub.3 " " "32 ##STR44## CH.sub.2 CHCH.sub.2 " "33 ##STR45## ##STR46## " "34 ##STR47##35 ##STR48## " " "36 ##STR49## " " "37 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " "38 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "39 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "40 C.sub.3 H.sub.6 OCH.sub.3 " " "41 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "42 ##STR50## " " "43 C.sub.3 H.sub.6 OCH.sub.3 ##STR51## " dull blue bluish black44 ##STR52## " " "45 ##STR53## " " "46 ##STR54## ##STR55## " greenish blue bluish black47 ##STR56## " " "48 ##STR57## " " "49 ##STR58## " " "50 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " "51 ##STR59## " " "52 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "53 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "54 ##STR60## " " "55 C.sub.3 H.sub.6 OCH.sub.3 " " "56 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "57 CH.sub.2 CH.sub.2 OCH.sub.3 " " dull blue bluish black58 C.sub.3 H.sub.6 OCH.sub.3 " H "59 ##STR61## ##STR62## CH.sub.3 "60 ##STR63## " " "61 ##STR64## " " "62 ##STR65## " " "63 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " "64 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "65 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "66 ##STR66## " " "67 C.sub.3 H.sub.6 OCH.sub.3 " " "68 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "69 C.sub.2 H.sub.4 OCH.sub.3 " " "70 C.sub.3 H.sub.6 OCH.sub.3 " H "71 " " C.sub.2 H.sub.5 "72 C.sub.4 H.sub.9 (n) " CH.sub.3 "73 C.sub.3 H.sub.6 OCH.sub. 3 ##STR67## " "74 ##STR68## ##STR69## " bluish grey coal black75 ##STR70## " " "76 ##STR71## " " "77 ##STR72## " " "78 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " "79 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "80 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "81 ##STR73## " " "82 C.sub.3 H.sub.6 OCH.sub.3 " " "83 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "84 ##STR74##85 ##STR75## " " "86 ##STR76## " " "87 C.sub.2 H.sub.4 OCH.sub.3 " " "88 C.sub.3 H.sub.6 OCH(CH.sub.3).sub.2 " " "89 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " "90 C.sub.3 H.sub.6 OCH.sub.3 " H "91 " " C.sub.2 H.sub.5 "92 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " H "93 ##STR77## ##STR78## CH.sub.3 dull blue coal black94 ##STR79## " " "95 ##STR80## " " "96 ##STR81## " " "97 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " "98 ##STR82## " " "99 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " "100 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " "101 ##STR83## " " "102 C.sub.3 H.sub.6 OCH.sub.3 " " "103 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " "104 ##STR84## " " "105 ##STR85## " " "106 ##STR86## " " "107 C.sub.2 H.sub.4 OCH.sub.3 " " "108 C.sub.3 H.sub.6 OCH.sub.3 ##STR87## " bluish grey coal black__________________________________________________________________________ TABLE 2______________________________________ ##STR88##No. R.sup.1 R.sup.2 R.sup.3 Hue______________________________________109 ##STR89## ##STR90## H blue navy110 ##STR91## " " blue navy111 ##STR92## " " blue navy112 ##STR93## " " blue navy113 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " blue navy114 ##STR94## " " blue navy115 CH.sub.2 CH.sub.2C.sub.6 H.sub.5 " " blue navy116 ##STR95## " " blue navy117 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " blue navy118 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) ##STR96## H blue navy119 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " blue navy120 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy121 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " blue navy122 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " blue navy123 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " blue navy124 ##STR97## " " blue navy125 ##STR98## " Cl blue navy126 ##STR99## ##STR100## H blue navy127 ##STR101## " Cl blue128 ##STR102## " " "129 ##STR103## " " "130 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 ##STR104## H blue navy131 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " blue navy132 C.sub.2 H.sub.4 OC.sub.2 H.sub.7 (i) " " blue navy133 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " blue navy134 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy135 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " blue navy136 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " blue navy137 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " blue navy138 ##STR105## ##STR106## " navy bluish black139 ##STR107## " " navy bluish black140 ##STR108## " " navy bluish black141 ##STR109## " " navy bluish black142 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " navy bluish black143 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) ##STR110## H navy bluish black144 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) " " navy bluish black145 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " navy bluish black146 C.sub.3 H.sub.6 OCH.sub.3 " " navy bluish black147 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " navy bluish black148 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " navy bluish black149 CH(CH.sub.3).sub.2 " " blue navy150 ##STR111## ##STR112## H blue navy151 ##STR113## " " blue navy152 ##STR114## " " blue navy153 ##STR115## " " blue navy154 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " blue navy155 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " blue navy156 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) ##STR116## H blue navy157 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " blue navy158 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy159 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " blue navy160 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " blue navy161 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " blue navy162 ##STR117## ##STR118## " navy163 ##STR119## " " "164 ##STR120## ##STR121## " greenish blue navy165 ##STR122## " " greenish blue navy166 ##STR123## " " greenish blue navy167 ##STR124## " " greenish blue navy168 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " greenish blue navy169 ##STR125## ##STR126## H greenish blue navy170 CH.sub.2 CH.sub.2C.sub.6 H.sub.5 " " greenish blue navy171 ##STR127## " " greenish blue navy172 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " greenish blue navy173 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) " " greenish blue navy174 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " greenish blue navy175 C.sub.3 H.sub.6 OCH.sub.3 " " greenish blue navy176 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " greenish blue navy177 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " greenish blue navy178 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " greenish blue navy179 ##STR128## " " greenish blue navy180 C.sub.2 H.sub.4 OCH.sub.3 " " greenish blue navy181 ##STR129## ##STR130## " blue navy182 ##STR131## " " blue navy183 ##STR132## ##STR133## H blue navy184 ##STR134## " " blue navy185 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " blue navy186 CH.sub.2 CH.sub.2C.sub.6 H.sub.5 " " blue navy187 ##STR135## " " blue navy188 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " blue navy189 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) " " blue navy190 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " blue navy191 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy192 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " blue navy193 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " blue navy194 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " blue navy195 ##STR136## " " blue navy196 C.sub.2 H.sub.4 OCH.sub.3 " " blue navy197 ##STR137## ##STR138## H blue navy198 ##STR139## ##STR140## " blue navy199 ##STR141## " " blue navy200 ##STR142## " " blue navy201 ##STR143## " " blue navy202 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " blue navy203 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " blue navy204 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) " " blue navy205 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " blue navy206 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy207 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " blue navy208 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " blue navy209 C.sub.3 H.sub.6 OC.sub.8 H.sub.17 (i) " " blue navy210 ##STR144## ##STR145## H navy211 " C.sub.3 H.sub.6 OCH.sub.3 " "212 ##STR146## ##STR147## " blue navy213 ##STR148## " " blue navy214 ##STR149## " " blue navy215 ##STR150## " " blue navy216 C.sub.2 H.sub.4 OC.sub.2 H.sub.5 " " blue navy217 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n) " " blue navy218 C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (i) " " blue navy219 C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n) " " blue navy220 C.sub.3 H.sub.6 OCH.sub.3 " " blue navy221 C.sub.3 H.sub.6 OC.sub.2 H.sub.5 " " blue navy222 C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n) " " blue navy223 C(CH.sub.3).sub.3 ##STR151## " blue navy224 C.sub.6 H.sub.5 ##STR152## " blue navy225 C.sub.4 H.sub.9 (n) ##STR153## " blue navy226 ##STR154## C.sub.6 H.sub.5 " blue navy______________________________________

Claims

1. A benzisothiazolylazo dye of the formula ##STR155## wherein one of R.sup.1 or R.sup.2 is phenyl substituted by methoxy, and the other R.sup.1 or R.sup.2 is methoxyethyl, ethoxyethyl, methoxypropyl, ethoxypropyl, --CH(C.sub.2 H.sub.5)--CH.sub.2 OCH.sub.3 or --CH(CH.sub.3)--CH.sub.2 OCH.sub.3.

2. The dye of claim 1, wherein R.sup.1 is phenyl substituted by methoxy and R.sup.2 is methoxyethyl.

3. The dye of claim 1, wherein R.sup.1 is phenyl substituted by methoxy and R.sup.2 is ethoxyethyl.

4. The dye of claim 1, wherein R.sup.1 is phenyl substituted by methoxy and R.sup.2 is methoxypropyl.

5. The dye of claim 1, wherein R.sup.1 is phenyl substituted by methoxy and R.sup.2 is ethoxypropyl.

6. The dye of claim 1, wherein R.sup.1 is phenyl substituted by methoxy and R.sup.2 is --CH(C.sub.2 H.sub.5)--CH.sub.2 OCH.sub.3.

7. The dye of claim 1, wherein R.sup.1 is phenyl substituted by methoxy and R.sup.2 is --CH(CH.sub.3)--CH.sub.2 OCH.sub.3.

8. The dye of claim 1, wherein R.sup.1 is methoxyethyl and R.sup.2 is phenyl substituted by methoxy.

9. The dye of claim 1, wherein R.sup.1 is ethoxyethyl and R.sup.2 is phenyl substituted by methoxy.

10. The dye of claim 1, wherein R.sup.1 is methoxypropyl and R.sup.2 is phenyl substituted by methoxy.

11. The dye of claim 1, wherein R.sup.1 is ethoxypropyl and R.sup.2 is phenyl substituted by methoxy.

12. The dye of claim 1, wherein R.sup.1 is --CH(C.sub.2 H.sub.5)--CH.sub.2 OCH.sub.3 and R.sup.2 is phenyl substituted by methoxy.

13. The dye of claim 1, wherein R.sup.1 is --CH(CH.sub.3)--CH.sub.2 OCH.sub.3 and R.sup.2 is phenyl substituted by methoxy.