Thiazolidine compounds for corrosion inhibition

Abstract

The present invention relates to the use of a thiazolidine compound of the formula (I) for reducing or inhibiting surfaces corrosion, for example in applications such as water treatment, industrial cleaning and especially in automatic dishwashing (ADW). Moreover, the present invention also relates to a method for reducing or inhibiting surfaces corrosion using said thiazolidine compound. Furthermore, the present invention relates to specific thiazolidine compounds and to a process for producing these compounds. (I) wherein R1 is selected from the group consisting of hydrogen and C1-4-alkyl; R2 is selected from the group consisting of hydrogen, carboxyl, C1-10- alkoxycarbonyl, C1-20-alkyl, C2-10-alkenyl, where C1-20-alkyl and C2-10-alkenyl are unsubstituted or substituted by 1 or 2 of the groups Ra, etc.; R3 is selected from the group consisting of hydrogen and C1-4-alkyl; R4 is selected from the group consisting of hydrogen, NH-C(=O)-NH2 and C1-4- alkyl; X is selected from the group consisting of hydrogen, alkali metal ions, C1-20- alkyl, C2-10-alkenyl and C6-12-aryl-C1-4-alkyl, where C6-12-aryl is unsubstituted or substituted by 1, 2 or 3 substituents Rc; Ra is selected from the group consisting of COOH, OH, C1-10-alkoxycarbonyl, C1-10-alkylcarbonyl, C2-10-alkenyl, NHC(=O)Rd, C3-10-cycloalkyl, C6-10-bicyclo- alkyl, C5-10-cycloalkenyl, 5-or 6-membered heterocyclyl bearing 1 or 2 heteroatoms selected from O, S and N, where C3-10-cycloalkyl, C6-10-bicycloalkyl, C5-10-cycloalkenyl and heterocyclyl are unsubstituted or substituted by 1, 2 or 3 substituents Rb, C6-12-aryl, such as phenyl, and 5- or 6-membered hetaryl, such as furyl and pyridyl, where C6-12-aryl and hetaryl are unsubstituted or substituted by 1, 2 or 3 substituents Rc; Rb is C1-4-alkyl, OH or two groups Rb bound to the same carbon atom are =O; Rc is selected from the group consisting of OH, C1-4-alkyl and O-C1-4-alkyl; and Rd is selected from the group consisting of H and C1-4-alkyl.

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