title: On the synthesis and reactivity of the Z-2,4-dinitrophenylhydrazone of 5-amino-3-benzoyl-1,2,4-oxadiazole.
abstract: The synthesis of the title compound (4b) has been completed: its rearrangement (in dioxane/water; 1:1, v/v) into N-(2,4-dinitrophenyl)-5-phenyl-2H-1,2,3-triazol-4-ylurea (7) has been quantitatively studied in a wide reactivity (at 293 K, k(A) 10(-8) -4 s(-1)) and pS+ (4.5-14.1) range and compared with that of the Z-2,4-dinitrophenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (10), of the 3-(p-nitro)phenylureine of 5-phenyl-1,2,4-oxadiazole (13), and of N-(5-phenyl-1,2,4-oxadiazol-3-yl)-N'-p-nitrophenylformamidine (14). The results (reactivity, occurrence of specific or general base-catalysis, evidence for or absence of rate-limiting constants) have been well interpreted considering the structure of the side-chains involved and the stability of the final rings obtained in the rearrangements.
authors.affiliation: Dipartimento di Chimica Organica A Mangini, Bologna, Italy.
authors.forename: B
authors.initials: B
authors.lastname: Cosimelli
authors.forename: S
authors.initials: S
authors.lastname: Guernelli
authors.forename: D
authors.initials: D
authors.lastname: Spinelli
authors.forename: S
authors.initials: S
authors.lastname: Buscemi
authors.forename: V
authors.initials: V
authors.lastname: Frenna
authors.forename: G
authors.initials: G
authors.lastname: Macaluso