Patent GB-814375-A (GB)
Title: Optically sensitised silver halide emulsions
IPC: G03C1/494
Filed: 1956-05-24
Abstract: N,N1 - Hexamethylene - bis - (thiopyrrolidone-2) is prepared by heating hexamethylenediamine with butyrolactone in the autoclave at 260-280 DEG  C.  The pyrrolidone formed is stirred with phosphorus pentasulphide and magnesia in xylene.  The product is decomposed with aqueous sodium hydroxide.  It may then be quaternized with dimethyl sulphate to give N,N1 - hexamethylene - bis - (2 - methylmercapto - pyrrolenine metho - sulphate).  N,N1 - ethylene - bis - (thiopyrrolidone - 2) is similarly prepared and treated with dimethylsulphate. Similarly N-butyl-, N-ethyl- or N-methyl-2-thiopyrrolidone is reacted with dimethyl sulphate to give a 2-methylmercaptoquaternary salt.  2-Methylmercapto-pyrrolenine is quaternized by reaction with propane sultone or b -iodopropionic acid.  N - Phenyl - 2 - thiopyrrolidone is prepared by melting N-phenyl-2-pyrrolidone with excess phosphorus pentasulphide.  The product may then be reacted with methyl iodide to give N-phenyl-2-thiopyrrolidone methiodide.  2 - Methylmercapto - 5 - spirocyclohexyl - 1 - pyrroline is prepared by melting 5-spirocyclohexyl-pyrrolidone-2 with excess phosphorus pentasulphide, and treating the product with dimethyl sulphate.  It may then be quaternized by further treatment with dimethyl sulphate.  2 - Methylmercapto - 3 - cyclohexyl - 1 - pyrroline is similarly prepared and quaternized with dimethyl sulphate.  2-Thiopiperidone is prepared by treating 2-piperidone in chloroform with phosphorus pentasulphide. The 2-thiopiperidone produced may be reacted with methyl iodide in alcoholic sodium alcoholate to give 2-methylmercapto-3,4,5,6 - tetrahydropyridine, which is then quaternized with dimethyl sulphate. Thiocaprolactam is prepared by treating caprolactam with phosphorus pentasulphide.  It may be methylated with dimethyl sulphate in caustic soda and further treated with dimethyl sulphate to give a quaternary salt.  Thiocapryllactam is similarly prepared from capryllactam, phosphorus pentasulphide and magnesia in chloroform. It may be similarly methylated and quaternized with dimethyl sulphate.  Specifications 450,958, 532,098, [both in Group IV], and German Specification 927,043 are referred to.ALSO:Dyes of the general formula <FORM:0814375/IV (c)/1> wherein R is an aralkyl, aryl, substituted aryl, cycloalkyl or alkyl group, or an alkyl group substituted with carboxylic acid, carboxylic ester or sulphonic acid groups, Z represents from 3 to 7 methylene groups forming a ring with the adjacent nitrogen and carbon atoms, one of which methylene groups may carry an alkyl or cycloalkyl substituent or the methylene groups necessary to complete a spiro-cyclohexyl nucleus, and A completes a 5- or 6-membered ring, are prepared according to the method of German Specification 927,043 by reacting a quaternary salt of the appropriate heterocyclic nitrogen compound having a 2-thioether or 2-selenoether substituent with a cyclic ketomethylene compound.  R may be methyl, ethyl, n-propyl, n-butyl, n-amyl, n-dodecyl, isopropyl, isobutyl, isoamyl, cyclohexyl, phenyl, naphthyl, chlorophenyl, benzyl or phenylethyl, carboxymethyl or b -carboxyethyl either of which may be esterified with e.g. methyl, ethyl or cyclohexyl alcohol; and propylene-o -sulphonic acid or butylene-o -sulphonic acid.  The ring completed by A may be thiohydantoin, rhodanine, isorhodanine, selenorhodanine, thionaphthenone, indandione or 5-pyrazolone.  In the examples, N-ethyl-rhodanine is reacted with the dimethyl sulphate of 2-methylmercapto - tetrahydropyridine, methylthiocaprolactam, 2 - methylmercapto - 5 - spirocyclohexyl - 1 - pyrroline, or methylthiocapryllactam, or with the quaternary salt from 2-methyl-mercapto-pyrrolenine and propane sultone or b -iodo-propionic acid; the dimethyl sulphate of N-butyl-thiopyrrolidone is reacted with N-ethyl-selenorhodanine or N-ethyl-rhodanine; N - phenyl - 2 - thiopyrrolidone - methiodide is reacted with N-ethyl-rhodanine; the dimethyl sulphate of 2-mercaptomethyl-3-cyclohexyl-1-pyrroline is reacted with N-phenylselenorhodanine; and the dimethyl sulphate of N - methyl - thiopyrrolidone is reacted with N - ethyl - 2 - thio - 2; 4 - oxazolidione - 5.  Dyes of the general formula <FORM:0814375/IV (c)/2> wherein R1 is an alkylene radical, are similarly prepared. Thus the dimethyl sulphate of N,N1-hexamethylene - bis - (thiopyrrolidone - 2) or N,N1 - ethylene - bis - (thiopyrrolidone - 2) is reacted with N-ethylrhodanine. Alternatively, the quaternary salts may be reacted with two heterocyclic ketomethylene groups joined through their carbon atoms by an alkylene group, to give dyes of the general formula <FORM:0814375/IV (c)/3> wherein the symbols are as defined above.  Thus the dimethyl sulphate of N-ethyl-thiopyrrolidone-2 is reacted with N : N1-ethylene-bis-rhodanine.  Specifications 450,958 and 532,098, [both in Group IV], also are referred to.