Patent GB-944301-A (GB)
Title: Trinuclear cyanine dyes
Inventor: FICKEN GEOFFREY ERNEST
IPC: C09B23/12
Filed: 1961-02-16
Abstract: Triethylammonium 2-bromo-ethyl sulphate is prepared by fusing the triethylamine-sulphur trioxide complex NEt3-SO3 with 2-bromoethanol at 160 DEG C. Specification 845,586 is referred to.ALSO:The invention relates to trinuclear cyanine dyes of the general formula I <FORM:0944301/C3/1> wherein R1 is an alkyl or aryl group, R3 is an alkyl group of up to 6 carbon atoms substituted by a carboxylic acid, sulphonic acid, sulphuric acid, hydroxy, alkoxy, acyloxy, carbalkoxy, cyano, amino, alkyl-substituted amino or carbamyl group, R4 is H or alkyl, R2 and R5 are alkyl, hydroxy alkyl (including b g -dihydroxypropyl) or aralkyl groups, m, n1 and n2 are 0 or 1, X is an anion, Y is H or alkoxy, and D1 and D2 complete 5- or 6-membered heterocyclic nuclei, and also to the corresponding anhydro dyes formed by loss of X and a hydrogen atom from the group R3 when the latter contains a sulphonic, sulphuric or carboxylic acid substituent, and the corresponding acid addition salts of those dyes wherein R3 contains an alkylamino substituent.  The dyes are prepared by reacting a dye of the general formula II <FORM:0944301/C3/2> with a compound of the general formula III <FORM:0944301/C3/3> wherein Q is an -SR, -CH=CH-SR or acetanilidovinyl group (R=an alkyl group of 1 to 6 carbons).  The dyes of formula II above may be prepared by reacting a compound of the formula <FORM:0944301/C3/4> with a compound of formula <FORM:0944301/C3/5> in the presence of an orthoacetate, or with a compound of the formula <FORM:0944301/C3/6> wherein T is a thioether or substituted amino group, the product in either case being quaternized with a salt R3X.  The dyes of formula II above wherein R4 is H may also be prepared by reacting a cyclammonium quaternary salt having a reactive a - or g -alkylthio group with a compound of the formula <FORM:0944301/C3/7> and quaternizing the product with a salt R3X. Examples are given of unquaternized compounds of formula II wherein D1 completes a thiazole, benzthiazole, naphthothiazole or benzselenazole nucleus, R1 is methyl, ethyl or phenyl, R4 is H or CH3, and Y is H or CH3O, and of the quaternization of these by heating in chloroform or 2-methoxy-ethanol with 2-bromoethanol, iodo-acetonitrile, b -bromopropionitrile, b -ethoxyethyl bromide, 1-bromopropan-2-ol, 3-iodopropan-1-ol, 1,2-dihydroxy-3-iodopropane, 2-iodoethyl acetate, ethyl bromoacetate, b  - iodopropionamide, b  - diethylaminoethyl bromide hydrobromide, 3-bromo- or iodopropionic acid, sodium 2-bromo- or iodoethane sulphonate, bromoacetic acid, 2-bromopropionic acid, 2-bromo-isobutyric acid, sodium 4-iodobutane sulphonate, triethylammonium 2-bromoethyl sulphate or methyl-3-iodopropionate. The intermediates are then reacted with compounds of formula III wherein D2 completes a benzthiazole, indolenine or 2-quinoline nucleus.  In Example 37, an anhydro dye is prepared by running a solution of bis-(3-methyl - 2 - benzothiazole) b  - (2 - 21 - carboxy - ethylthio - 1 - phenyl - 3 - indolyl) - trimethine cyanine iodide in methanol and chloroform through an ion-exchange column.  In Example 38, an anhydro dye is formed directly by reaction of a salt of formula II with one of formula III.  Specification 845,586 is referred to.