Patent GB-759323-A (GB)
Title: Process of preparing dye intermediates and of making merocyanine dyes therefrom and photographic emulsions sensitized with such dyes
IPC: C07D277/20
Filed: 1954-08-26
Abstract: Thio-thiazolidones of the general formula <FORM:0759323/IV(a)/1> wherein R and R1 may be hydrogen, an alkyl, substituted alkyl, cycloalkyl, allyl, aralkyl or aryl group or together complete a heterocyclic ring, R2 is hydrogen or an alkyl group and R3 represents an alkyl, substituted alkyl, alkenyl, cycloalkyl, aralkyl or aryl group, are prepared by condensing a compound of the formula <FORM:0759323/IV(a)/2> wherein R6 represents an alkyl group, with a compound of the formula R.NH.R1.  The product may be quaternized by heating it with a compound of the formula R5X wherein R5 is an alkyl or aryl group and X is an anion.  R and R1 may be methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, n-octyl, carboxymethyl, carbomethoxy methyl, b -hydroxyethyl, benzyl, phenyl, o-, m- or p-tolyl, cyclobutyl, cyclopentyl or cyclohexyl or they may together complete a piperidyl or morpholinyl ring. R2 may be methyl or ethyl and R3 may be methyl, ethyl, carbethoxymethyl, allyl or benzyl. Examples are given of the preparation of compounds of formula I.  The compounds of formula II wherein R2 is hydrogen are described in Specification 633,736 but further details of the preparation of such compounds are given as well as those wherein R2 is methyl or ethyl. In these preparations R6 is methyl or ethyl.  Specifications 528,803, 544,647, [both in Group IV], and 742,206 also are referred to.ALSO:A merocyanine dye of the general formula <FORM:0759323/IV(c)/1> wherein R and R1 represent hydrogen an alkyl, substituted alkyl, cycloalkyl, allyl, aralkyl or aryl group or together complete a heterocyclic ring, R2 is hydrogen or an alkyl group, R3 represents an alkyl, substituted alkyl, alkenyl, cycloalkyl, aralkyl or aryl group, R4 represents hydrogen or an alkyl group or, where Q completes a pyrazolone, oxazolone or thiazolone nucleus, an alkoxy group, n is 0 or 1 and Q completes a 5 membered heterocyclic nucleus, is prepared by condensing a compound of the formula <FORM:0759323/IV(c)/2> wherein R5 represents an alkyl or aryl group and X is an anion, with a compound of the formula <FORM:0759323/IV(c)/3> or <FORM:0759323/IV(c)/4> is described wherein the corresponding 2-thio-thiazolid-4-one merocyanine dye of formula VI is quaternized and reacted with 3-allyl rhodanine.  The trinuclear dye may again be quaternized and reacted with 3-allyl rhodanine to give a tetranuclear dye. The unquaternized compounds corresponding to formula V above are prepared by condensing a compound of the formula R and R1 may be methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, n-octyl, carboxy methyl, carbomethoxymethyl, b -hydroxyethyl, benzyl, phenyl, o-, m- or p-tolyl, cyclobutyl, cyclopentyl or cyclohexyl or they may together complete a piperidyl or morpholinyl ring.  R2 may be methyl or ethyl, R3 may be methyl, ethyl, carbethoxymethyl, allyl or benzyl, R4 may be methyl or ethyl and, in certain cases methoxyl or ethoxyl and R5 may be methyl, ethyl, phenyl or o-, m- or p-tolyl.  A list of nuclei which Q may complete is given including 3-(1-benzthiazyl) rhodanine, 2-diphenyl and 2-alkyl phenylamino-4-thiazolones, isoazolones and thionaphthenones.  It is stated that when R and/or R1 is hydrogen, the dyes can be acylated with acetic, propionic, butyric, iso butyric or benzoic anhydrides.  The preparation of a dye having the formula <FORM:0759323/IV(c)/5> wherein R6 represents an alkyl group with a compound of the formula RNHR1.  Specifications 528,803, 544,647, 636,736 [Group IV(b)], and 742,206 are referred to.