4-QUINOLYLBENZIMIDAZOLE QUATERNARY SALTS AS INHIBITORS OF STEEL CORROSION IN HYDROCHLORIC ACID SOLUTION Russian patent published in 1998 - IPC

FIELD: organic chemistry. SUBSTANCE: invention relates to heterocyclic compounds, in part, 4-quinolylbenzimidazole quaternary salts - 4-(benzimidazolyl-2')-quinoline diethylsulfates or its 2-phenyl- or 2-methyl-substituents. Synthesis is carried out by short time heating the corresponding substituted quinolines as hydrates with diethylsulfate in medium of an organic solvent. Yield, %; m. p., C; empirical formula; inhibitory activity at 30 and 90 C in 10% HCl (concentration is 0.8 g/l, solvent - AM, ratio = 1: 8): a) 20; 265-267; C₂₄H₃₁N₃S₂O₈; 85.2 and 83.0; b) 36.8; above 300; C₂₅H₃₃N₃S₂O₈; 86.6 and 87.4; c) 29; 210-212; C₃₀H₃₅N₃S₂O₈•H₂O;; 99.8 and 99.6. EFFECT: improved method of synthesis, increased yield, enhanced effectiveness. 2 tbl