Patent GB-670799-A (GB)
Title: Improvements in and relating to photographic silver halide emulsions
IPC: G03C1/12
Filed: 1949-06-27
Abstract: N - Tetrahydrofurfuryl - 2 - methylbenzthiazole bromide is prepared by heating together in a sealed tube 2-methylbenzthiazole and tetrahydrofurfuryl bromide.  N - Tetrahydrofurfuryl - 2 - methylbenzoxazole p-toluenesulphonate is prepared by heating together 2-methylbenzoxazole and tetrahydrofurfuryl p-toluenesulphonate. Tetrahydrofurfuryl p-toluenesulphonate is prepared by mixing together p-toluenesulphochloride, tetrahydrofurfuryl alcohol, and finely pulverised KOH in ether, whilst cooling with ice.  The Specification as open to inspection under Sect. 91 comprises also the preparation of N - tetrahydrofurfuryl - 2 - methylthiazoline bromide by heating together 2-methylthiazole, tetrahydrofurfuryl bromide, and absolute ethyl alcohol. N-Tetrahydrofurfuryl - 6 - methoxy - 2 - methylbenzthiazole bromide and N-tetrahydrofurfurylquinaldine bromide are similarly prepared.  N - Tetrahydrofurfuryl - 2 - methylbenzselenazole bromide is prepared by heating together 2-methylbenzselenazole and tetrahydropropyl bromide.  This subject-matter does not appear in the Specification as accepted.ALSO:3 : 31 - Di - (tetrahydrofurfuryl) - 9 - methylthiacarbocyanine bromide is prepared by refluxing together N-tetrahydrofurfuryl-2-methylbenzthiazole bromide, ethyl orthoacetate, and pyridine.  3 - Tetrahydrofurfuryl - 31 - methyl - 9-ethyl - 41 : 51 - benzthiacarbocyanine iodide is prepared by refluxing together N-tetrahydrofurfuryl - 2 - methylbenzthiazole bromide, 2-(b  - methylmercapto - b  - ethylvinyl) - a -dihydronaphthathiazole dimethylsulphate, alcohol, and triethylamine. 3 : 31 - Di - (tetrahydrofurfuryl) - oxacarbo cyanine iodide is prepared by boiling together N-tetrahydrofurfuryl-2-methylbenzoxazole p-toluenesulphonate, ethyl orthoformate, and acetic anhydride, and treating with aqueous KI solution.  3-Tetrahydrofurfuryl - 31 - ethyloxathiazolinocarbocyanine bromide is prepared by boiling together N-tetrahydrofurfuryl - 2 - b  - anilidovinylbenzoxazole, p - toluenesulphonate, 2 - methylthiazoline ethobromide, and acetic anhydride.  N - Tetrahydrofurfuryl - 2 - b  - anilidovinylbenzoxazole p-toluenesulphonate is prepared by heating together N - tetrahydrofurfuryl - 2-methylbenzoxazole p-toluenesulphonate and diphenylformamidine.  3 : 31 - Di - (tetrahydrofurfuryl) - thiadicarbocyanine bromide is prepared by refluxing together N-tetrahydrofurfuryl - 2 - methylbenzthiazole bromide and b  - anilinoacroleinanil in pyridine, adding N-tetrahydrofurfuryl - 2 - methylbenzthiazole bromide, triethylamine, and pyridine, and further boiling.  3 : 31 - Di - (tetrahydrofurfuryl)-thiatricarbocyanine bromide is prepared by heating together N - tetrahydrofurfuryl - 2-methylbenzthiazole bromide, glutaconic dialdehyde dianilide hydrochloride, and absolute alcohol, adding aqueous sodium ethylate solution, and further heating.  The Specification as open to inspection under Sect. 91, comprises also the preparation by similar methods of 3-tetrahydrofurfuryl-31-p -carboxybenzylthiazolinooxacarbocyanine iodide, 3 - tetrahydrofurfuryl - 31 : 9 - diethyl - 41 : 51-benz - 6 - methoxythiacarbocyanine iodide, 3 : 31-di - (tetrahydrofurfuryl) - 9 - methylselenacarbocyanine bromide, the preparation of 2-acetylmethylene - 3 - tetrahydrofurfuryldihydrobenzthiazole by adding acetyl chloride to a suspension of N-tetrahydrofurfuryl-2-methylbenzthiazole bromide is pyridine at 0 DEG  C., the preparation of 3 - ethyl - 31 - tetrahydrofurfuryl - 9-methyloxathiacarbocyanine iodide by boiling 2-acetylmethylene - 3 - tetrahydrofurfuryldihydrobenzthiazole with 2-methylbenzoxazoleethiodide in acetic anhydride, the preparation of 3 - allyl - 5 - (3 - tetrahydrofurfurylbenzthiazolylidene - a  - methylethylidene) - rhodenine by boiling 2 - acetylmethylene - 3 - tetrahydrofurfuryldihydrobenzthiazole with N - allylrhodamine in acetic anhydride, and the preparation of 1 - tetrahydrofurfuryl - 11 - ethyl - 2 : 21-cyanine iodide by boiling quinaldine tetrahydrofurfuryl bromide with 2-methylmercaptoquinoline ethiodide and triethylamine.  This subject-matter does not appear in the Specification as accepted.