The efficient synthesis of new fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones [Cl3CC(O)C(R²)=C(R¹)OMe, where R¹ = n-hexyl, heptyl, nonyl, undecyl, tridecyl and R² = H] and 1,1,1-trichloro-2,4-alkanediones [Cl3CC(O)CHR²C(O)R¹, where R¹ = n-pentyl and R² = Me, R¹ = Et and R² = n-butyl, R¹ = n-butyl and R² = n-propyl] in good yields (85-95%) from acetal acylation with trichloroacetyl chloride is reported. The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1,1,1-trichloro-2,4-alkanediones were reacted with hydrazine hydrochloride, leading to respective 1H-pyrazole-5-carboxylates, unusual class of fatty acid methyl (FAMEs) and ethyl (FAEEs) esters. Their structures were confirmed by elemental analysis and ¹H and 13C nuclear magnetic resonance (NMR). The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1H-pyrazole derivatives are new oleochemicals with potentially interesting and differential properties.
fatty ketones; acylation; fatty 1H-pyrazoles
