Search results for " diketone"
showing 2 items of 2 documents
ELABORATION OF CURCUMIN INTO DIKETONE MODIFIED ANALOGUES DEVOID OF NUCLEOPHILIC ADDITION CAPABILITY; IMPLICATIONS FOR THEIR ANTITUMOR AND CHEMOSENSIT…
2009
Curcumin (CUR), a polyphenolic compound extracted from Curcuma longa L.,can beconsidered as a good lead compound for the design of new drugs for the treatment of cancer and other therapeutic purposes. CUR is endowed with a diketone function, which appears to be important for its antitumor activity: also depending on the dose, the compound may show complex either pro-oxidant or anti-oxidant effects, which both may, at least in part, be linked to this structural moiety. In the lower concentration, "chemopreventive", range, CUR behaves mainly as an antioxidant; at higher concentrations, the a, b-unsaturated 1,3-diketone, as a Michael acceptor, can form adducts with the –SH groups and generate …
One-pot synthesis of fluorinated 2-amino-pyrimidine-N-oxides. Competing pathways in the four-atom side-chain rearrangements of 1,2,4-oxadiazoles
2006
Abstract Trifluoromethylated 2-amino-pyrimidine N-oxides have been synthesized by reaction of the 3-amino-5-methyl-1,2,4-oxadiazole with trifluoromethyl-β-diketones in the presence of perchloric acid, followed by hydrolysis. In this ring-to-ring transformation an initial formation of (unisolated) 1,2,4-oxadiazole-pyrimidinium salts, and subsequent ring-opening at the oxadiazole moiety occurs. Isolation of 2-(hydroxyamino)-pyrimidine from the reaction mixture evidenced the presence of a competing pathway where the N(4) nitrogen of the oxadiazole is involved in the formation of a regioisomeric pyrimidinium salt. The effect of the trifluoromethyl group on the product distribution is discussed.…