“…In 1 M HCl (20°C), 0.5 mM 2-amino-4,6-dihydroxypyrimidine provides good protection of carbon steel, Z = 94.5%, but at t = 50°C it decreases to 79.5% [50]. According to electrochemical studies, in 0.5 M H 2 SO 4 (20C) 10 mM 2-aminopyrimidine and 2,4-diaminopyrimidine hinder the corrosion of cold rolled steel (composition, mass%: С 0.07; Si 0.01; Mn 0,3; P 0.022; S 0,010; Al 0.030) to reach Z = 82.0 and 89.6%, respectively [51]. In dilute 0.05 M HNO 3 (30C) on 1018 carbon steel (composition, mass%: С 0.2; Si 0.003; Mn 0.6; P 0.04) at C in = 17 M, protection increases in the series: 2-aminopyrimidine 2,4-diaminopyrimidine 2,4-diamino-6-hydroxypyrimidine 2,4,6triaminopyrimidine, the observed effects being Z = 36.3, 42.7, 48.5 and 53.3%, respectively.…”