Patent GB-466244-A (GB)
Title: Improvements in the manufacture of dyes
IPC: C09B23/10
Filed: 1935-08-15
Abstract: Dyes having the structure <FORM:0466244/IV/1> <FORM:0466244/IV/2> where X = O or S and Y and Z are the same or different monovalent organic radicals or members of a common heterocyclic or homocyclic ring, and <FORM:0466244/IV/3> are the residues of nitrogen-containing ring compounds are made by condensing a compound containing a reactive methylene group directly attached to a CO or CS group with a formylmethylene compound of the general formulae <FORM:0466244/IV/4> <FORM:0466244/IV/5> wherein D = a vinylene or arylene group, R = alkyl and Y = the non-metallic atoms necessary to complete a 5-membered or 6-membered heterocyclic nucleus, such as an oxazole, e.g. 4-methyl- or 4-phenyloxazole, benzoxazole, or naphthoxazole, a thiazole, e.g. 4-methyl- or 4-phenylthiazole, benzthiazole or naphthathiazole, a selenazole, e.g. 4-methylselenazole or benzselenazole, a pyridine, a quinoline, e.g. 5-methylquinoline or a benzquinoline, a thiazoline, a selenazoline or an indolenine, e.g. a 3 : 3-dialkylindolenine nucleus.  The heterocyclic compounds containing a reactive methylene group directly attached to CO or CS specified are rhodanines, such as 2-thio-2 : 4-thiazoledione and its 3-alkyl and 3-aryl derivatives, 4-thiorhodanines, e.g. 2 : 4-dithio-2 : 4-thiazolediones and its 3-alkyl or 3-phenyl derivatives, 2-thio-2 : 4-oxazolediones, such as 3-ethyl-2-thio-2 : 4-oxazolediones, 4-thiazolidones, hydantoins, such as 2 : 4-imidazoledione, 2-thio-2 : 4-imidazolediones, 2 : 4-dithio-2 : 4-imidazolediones, 2 : 4-thiazolediones, barbituric acids, thiobarbituric acids, 2 : 4-dihydroxyquinolines and benzocoumarin; non-cyclic compounds containing a reactive methylene group directly attached to a CO or CS group exemplified are acetylacetone, benzoylacetone, naphthoylacetone, N-alkyl or N-aryl cyanoacetamides, malonic acid or its esters, ethyl-2-quinolylpyruvates, benzoylacetonitrile, acetoacetic esters; homocyclic compounds containing a reactive methylene group directly attached to a CO or CS group mentioned are 1 : 3-indandione and 1 : 3-cyclohexanedione.  The reaction advantageously takes place in presence of a water-binding agent, e.g. acetic anhydride or propionic and butyric anhydrides.  In the examples, (1)-(4) 1-ethyl-2-formylmethylene-b -naphthathiazoline is condensed in acetic anhydride with 3-ethylrhodanine, 3-ethyl-2-thio-2 : 4-oxazoledione, ethyl-2-quinolylpyruvate and acetylacetone.  The dyes are useful for sensitizing photographic silver salt emulsions and in the construction of light filters. They may also be used for textiles, particularly cellulose acetate artificial silk. Specification 466,268 is referred to.  Samples have been furnished under Sect. 2 (5) of dyestuffs prepared as above from (1) 4 - formylmethylene - 1 - methyl - 1 : 4 - dihydroquinoline and 3-ethylrhodanine; (2) 2-formylmethylene - 1 : 6 - dimethyl - 1 : 2 - dihydroquinoline and 3-ethyl-2-thio-2 : 4-oxazoledione; (3) and (4) 1-ethyl-2-formylmethylene-b -naphthothiazoline with hippuric acid and with aceturic acid, (formulae given).  According to the Provisional Specification formylmethylene derivatives of dihydroderivatives of heterocyclic compounds are used as starting materials.