6533b82dfe1ef96bd1291eb6
RESEARCH PRODUCT
One-pot synthesis of fluorinated 2-amino-pyrimidine-N-oxides. Competing pathways in the four-atom side-chain rearrangements of 1,2,4-oxadiazoles
Antonio Palumbo-piccionelloNicolò VivonaSilvestre BuscemiMarcella PaniAndrea Pacesubject
fluoropyrimidine derivativecrystal structurepyrimidine N-oxidePyrimidinesynthesisStereochemistryOne-pot synthesisOxadiazoleX ray analysis3 diketoneBiochemistryMedicinal chemistryperchloric acidnitrogenchemistry.chemical_compoundside-chain rearrangementDrug DiscoveryStructural isomerSide chainMoietyPerchloric acidring openingfluorinated heterocycle3 diketone fluoropyrimidine derivative ketone derivative nitrogen oxide perchloric acid; article crystal structure hydrolysis priority journal reaction analysis ring opening synthesis X ray analysisTrifluoromethylChemistryOrganic Chemistryarticle124-oxadiazoleketone derivativereaction analysishydrolysispriority journaloxidedescription
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. By X-ray analysis, the crystal structure of two different N-oxide regioisomers has been unambiguously ascertained.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-02-01 |