Water-soluble pyrazole derivatives as corrosion inhibitors

A method for inhibiting corrosion of a metal surface in contact with an aqueous system, the method comprising adding to the aqueous system a compound of formula (I),

• wherein X is selected from the group consisting of —OH, —NH2, —SH, and halogen;
• Y is selected from the group consisting of —CR4 and nitrogen;
• R1 and R2 form a six-membered aromatic ring or each of R1 and R2 is the same or different and selected from the group consisting of hydrogen, aryl, heteroaryl, C1-C16 alkyl, C2-C16 alkenyl, C2-C16 alkynyl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, hydroxyl, alkoxy, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
• R3 is selected from the group consisting of hydrogen, aryl, heteroaryl, C1-C16 alkyl, C2-C16 alkenyl, C2-C16 alkynyl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, hydroxyl, alkoxy, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
• R4 is selected from the group consisting of hydrogen, aryl, heteroaryl, C1-C16 alkyl, C2-C16 alkenyl, C2-C16 alkynyl, C3-C8 cycloalkyl, benzyl, alkylheteroaryl, halogen, halosubstituted alkyl, amino, aminoalkyl, cyano, hydroxyl, alkoxy, thiol, alkylthio, carbonyl, nitro, phosphoryl, phosphonyl, and sulfonyl;
• m is an integer of from 1 to 9;
• or
• a salt thereof;
• with the proviso that when m=2, R1═H, and Y═CR4 wherein R4 is methyl, then R2 is not methyl or pyridinyl;
• and
• the aqueous system comprises an oxidizing halogen compound and pH of from about 6 to about 12, wherein the oxidizing halogen compound is selected from chlorine bleach, chlorine, bromine, iodine, hypochlorite, hypobromite, iodine/hypoiodous acid, hypobromous acid, halogenated hydantoins, chlorine dioxide, a stabilized version of hypochlorous or hypobromous acid, and any combination thereof.