The oxime of 6,7-dihydro-6,6-dimethylbenzofurazan-4(5H)-one 3-oxide

Crystal structure of 7-(2-oxo-2,3-dihydro-1,3-benzoxazol-3-yl)-4,6-dimtrobenzofurazan 1-oxide

“…Compared to the typical Ν -Ο distance in nitro groups (1.21 A -1.23 Ä), the short bond N(l) -0(2) can be explained by the high thermal motion of the oxygen atom. The bonds of the furoxan ring lie in the range found in other furoxan rings (Britton and Noland, 1972;Britton and Olson, 1979;Calleri, Bonaccorti, and Viterbo, 1977;Calleri, Chawdhury, and Viterbo, 1976). In accordance to the literature the nitrogen atom with the N-oxide function Brought to you by | New York University Bobst Library Technical Service Authenticated Download Date | 7/1/15 10:33 AM The average deviations of the atoms from the least-squares planes of the five-and six-membered rings of the benzofuroxan and benzoxazole fragment are 0.012(6) A, 0.009(5) A and 0.001(6) A, 0.015(6) A, respectively.…”

6,7-Dihydro-6,6-dimethylbenzofurazan-4(5H)-one oxime

“…Since the effect is neatly shown by furoxan and furazan derivatives, it may be ascribed to the electron-withdrawing power of the N-O-N group of the pentaatomic ring. In the 3-oxide oxime derivative (Calleri, Bonaccorti & Viterbo, 1977a) this 'inductive' effect is accompanied by a limited conjugation between the oxime and the N ~ O functions, while in the 1-oxide isomer (CaUeri, Chawdhury & Viterbo, 1976) it is accompanied by a back-donation effect from the extranuclear O atom. The induction appears less marked in the 3-oxide ketone derivative where the X-ray results alone do not indicate the appreciable presence of any other effect.…”

“…The present investigation follows those on the 1-oxide and 3-oxide furoxan analogues and dihydrodimethylbenzofurazan-4(5H)-one 3-oxide (Calleri, Chawdhury & Viterbo, 1976;Calleri, Bonaccorti & Viterbo, 1977a;. All four compounds were prepared by A. J. Boulton and coworkers with the aim of investigating the tautomerism and possible rearrangement mechanisms (Ackrell & Boulton, 1973;.…”