Patent GB-509927-A (GB)
Title: Manufacture of dyestuffs
IPC: C09B23/01
Filed: 1937-12-20
Abstract: 509,927. Dyes. GROVES, W. W. (I.G. Farbenindustrie Akt.-Ges.). Dec. 20, 1937, No. 35207. [Class 2 (iii)] Dyes are made by condensing a quaternary salt of a heterocyclic nitrogen base containing a reactive methyl group in alpha- or #- position to the ring nitrogen atom, at ordinary or raised temperature, and in presence of a condensing agent, with a dyestuff prepared by condensing with an alkyl ester a condensation product derived from rhodanine or an N-substitution product thereof wherein the residue of a nitrogenous aromatic or heterocyclic base is linked directly or through an unsubstituted mono- or polymethine chain to the ring carbon atom of the rhodamine base which is in #-position to the ring nitrogen atom thereof. The reactive methyl group of the heterocyclic nitrogen base condenses with the thioalkyl group of the starting material with formation of a mercaptan. Formulae of starting materials are given. The dyes are suitable for the optical sensitization of photographic silver halide emulsions. In the examples, (1) the dyestuff from thiazoline-2- monomethine-w-aldehyde and N-ethylrhodanine combined with methylsulphate is. condensed with 2-methyl-4:5-naphthathiazole ethyl iodide in presence of triethylamine in propanol; (2) the dye from ethylrhodanine and 1:3:3-trimethylindoline - 2 - monomehtine - w - aldehyde combined with diethylsulphate is condensed 2-methylbenzthiazole ethyl iodide in pyridine ; (3) the dye from rhodanine and 1:3:3-trimethyl- 5-methoxyindoline - 2-monomethine-w-aldehyde combined with dimethyl sulphate is condensed with 2-methylbenzselanazole ethyl iodide in isoquinoline ; (4) the condensation products from N-ethylbenzthiazole-2-monomethine-waldehyde, N-ethylrhodanine and dimethyl sulphate is condensed as in (3) with 4-5-diphenyl- 2-methyl-N-ethylthiazolium bromide ; (5) the intermediate product from 6-diethylamino-1- ethylbenzthiazolediphenylformamidine and N- allylrhodanine combined with dimethylsulphate is condensed with 2-methyl-4:5-naphthothiazole ethyl iodide as in (3) ; (6) the dye from N-ethylbenzthiazole-2-monomethine-w-aldehyde and ethylrhodanine combined with' dimethyl sulphate is condensed as in (3) with lepidine dimethyl sulphate ; (7) the dye from N-methylbenzthiazole-2-monomethine-w-aldehyde and rhodanine combined with dimethyl sulphate is condensed as in (3) with 2-methyl-4:5-naphthoxazole ethyl iodide ; (8) the dye from 6-methyl-2- methothiobenzoxazole dimethyl sulphate and allylrhodanine combined with dimethyl sulphate is condensed in pyridine with 2:6- dimethylbenzoxazole ethyl iodide ; (9) the dye from 2-methothiobenzthiazole ethyl sulphate and N-ethylrhodanine combined with dimethyl sulphate is condensed in pyridine with 2-methyl- 4:5-naphthathiazole ethyl-p-toluenesulphonate, or (10) in presence of isoquinoline with 2-methyl- 4:5-diphenyloxazole diethylsulphate; (11) the dye from p-dimethylaminobenzaldehyde and N-phenylrhodanine combined with diethylsulphate is condensed with 2-methyl-4:5-napthothiazole ethyl iodide in pyridine; (12) the dye from N-ethyl-2-methylindoline-5-aldehyde and ethylrhodamine and dimethylsulphate is condensed with 2-methylbenzthiazole ethyl iodide in presence of isoquinoline ; (13) the dye from tetrahydroquinoline-N-propenal, N-allylrhodanine and dimenthysulphate is condensed in pyridine with 2-methylbenzthiazole ethyl iodide ; (14) the dye N-ethyl-5-(1-ethyl-2- benzthiazolinobutadienyl)-rhodanine (cf. Specification 450,958) is combined with dimethylsulphate is condensed with 2-5:6-trimethylbenzoxazole ethyl-p-toluenesulphonate in pyridine and the product precipitated with potassium iodide ; (15) the intermediate of (14) is condensed in pyridine with 2-methyl-4-phenylthiazole diethylsulphate and the dye precipitated as the iodide. Specifications 423,792, 438,278, 438,420, 466,244, 466,245 and 505,839 also are referred to. .The Provisional Specification is not restricted to the use, as parent materials, of the dyestuffs derived from rhodamine or its N-substitution products, and includes the use of the dyestuffs obtained by the condensation of alkyl esters with the condensation products from nitrogenous aromatic or heterocyclic bases containing a reactive group in 2- or in pposition to the nitrogen atom and compounds containing the grouping -S-CH<2>-CO-NR- in general.