An example of 1,3-dipolar cycloaddition reactions of arylnitrile oxide to pyrazolo[1,5-a]pyrimidines was described. The nitrile oxide reacts with the C3 –C4 double bond of pyrazolo[1,5-a]pyrimidine to give the corresponding pyrazolo[1,5-a]pyrimidine -isoxazolidines in moderate yields. The mechanism was discussed and the structure of all compounds was studied by IR and NMR Spectroscopy (1H, 13C, 19F). Compound 4e was characterized by HRMS.
K. Bokri, I. Jalloul, M.L. Efrit, A. Ben Akacha
3,5-diaminopyrazole, pyrazolo[1,5-a]pyrimidine, 1,3-dipolar cycloaddition and arylnitrile oxide