PYRIDINE BIS-QUATERNARY SALTS AS ACTIVATORS OF SPECTRAL SENSIBILIZATION OF PHOTOGRAPHIC BROMINE-IODINE-SILVER EMULSIONS CONTAINING ANIONIC OR CATIONIC CYANINES Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: product: 1,4-bis-(N′-methylpyridinium-2′-bromide)-1,4-dithiabutane, empirical formula is C₁₄H₁₈N₂S₂Br₂, yield is 80.8%, m.p. is 184-185 C; 1,5-bis-(N′-methylpyridinium-2′-iodide)-1,5-dithiapentane, empirical formula is C₁₅H₂₀N₂S₂l₂, yield is 60.4%, m.p. is 201-202 C; 1,5-bis-(N′-methylpyridinium-2′-methanesulfonate)-1,5-diapentane, empirical formula is C₁₇H₂₆N₂O₆S₄ × 1/2H₂O, yield is 93.5% , m. p. is 110-111 C; 1,6-bis-(N′-methylpyridinium)-2′-methanesulfonate)-1,6-dithiahexane, C₁₈H₂₈N₂O₆S₄·H₂O, yield is 66.9%, m. p. is 174-175 C; 1,7-bis-(1,7-бис(N′-methylpyridinium-2′-bromide)-1,7-dithiaheptane, C₁₇H₂₄N₂S₂Br₂, yield is 97.5% , m. p. is 170-172 C; 1,7-bis-(N′-methylpyridinium-2′-tosylate)-1,7-dithia-4-oxaheptane, C₃₀H₃₆N₂O₇S₄, yield is 60.9%, m. p. is 162-163 C; 1,10-bis-(N′-methylpyridinium-2′-perchlorate)-1,10-dithia-4,7-dioxadecane, C₁₈H₂₆N₂O₁₀S₂Cl, yield is 51.2%, m. p. is 100-101 C; 1,5-bis-(N′-ethylpyridinium-2′-perchlorate)-1,5-dithiapentane, C₁₇H₂₄N₂O₈S₂Cl₂, yield is 63.6%, m. p. is 175-176 C; 1,5-bis-(N′-butylpyridinium-2′-perchlorate)-1,5-dithiapentane, empirical formula is C₂₁H₃₂N₂O₈S₂Cl₂· 4H₂O,, yield is 84%, m. p. is 83-84 C. EFFECT: increased yield of products indicated above. 3 tbl