Hemisynthesis, crystal structure and inhibitory effect of sesquiterpenic thiosemicarbazones and thiazolidin-4-ones on the corrosion behaviour of stainless steel in 1 M HSO solution.

Treatment of thiosemicarbazones prepared from sesquiterpenes with ethyl 2-bromoacetate in the presence of sodium acetate afforded the corresponding thiazolidin-4-ones. The structures of all the newly synthesized compounds were established by considering spectral and single-crystal X-ray diffraction data. The title compound, ethyl 2-((Z)-2-{(Z)-[(1aR,5aR,9aS)-1,1-dichloro-1a,5,5,7-tetramethyl-1a,2,3,4,5,5a,8,9-octahydro-1H-benzo[a]cyclopropa[b][7]annulen-8-ylidene]hydrazono}-4-oxothiazolidin-3-yl)acetate, CHClNOS, 5, crystallizes in the orthorhombic noncentrosymmetric space group P222 with Z = 4.