... The addition of hydroxylamine to the hydroxyguanidine 5 and its cyclization to the oxadiaz- olone 6 occur in polar organic solvents like DMSO or DMFA at room ... Chemistry" ... C=O).- 'H-NMR ([D]6DMSO): 6 = 1.25 (t, J = 7 Hz, 3 H, CHZ-CH~), 3.15 (s, 3H, N-CH3), 4.26 (q, J = 7 Hz ...