Reaktionen von 3-substituiertem 5-Trifluormethyl-1,3,4-oxadiazol-2(3H)-on mit Nucleophilen

Reactions of 3-Substituted 5-Trifluoromethyl-1,3,4-oxadiazol-2(3H)-one with Nucleophiles The 3-substituted 5-trifluoromethyl-1,3,4-oxadiazolones 3, 4, 13 , and 15 are attacked by N- and S-nucleophiles either at the ring C-atom C(2) or C(5). Depending on the nature of the substituent and the nucleophile, the ring-opening products 7, 10, 12 , and 14 or the ring-enlargement products 16 are formed. The reaction of 4 with thiols is a novel variant of the Grob-type fragmentation. The reactivity of the 1,3,4-oxadiazolones is compared with that of the analogous 1,3,4-thiadiazolones. The structures of the new compounds were elucidated by ¹H- and ¹³ C-NMR spectroscopy.