Copper-catalyzed cyclization of Z-oximes into 3-methyl-1,2-benzisoxazoles

Benzofuran-, benzothiophene-, indazole- and benzisoxazole-quinones: Excellent substrates for NAD(P)H:quinone oxidoreductase 1

“…The reaction mixture was stirred at room temperature overnight, and evaporated under reduced pressure. The crude product was purified by chromatography, eluting with ethyl acetate/light petroleum (1:3), to yield the title compound (4.72 g, 100%) as a yellow solid; mp 28–30 °C (lit., 43 mp not given); (Found: MH + , 164.0708. C 9 H 9 NO 2 + H requires 164.0712); ν max (KBr)/cm −1 2972, 2935, 1730, 1528, 1484, 1458, 1439, 1252, 1219, 1127, 1079, 1028; δ H (300 MHz; CDCl 3 ) 7.44 (1 H, d, J 9.0, 7-H), 7.16 (1 H, dd, J 9.0, 2.3, 6-H), 6.96 (1 H, d, J 2.3, 4-H), 3.87 (3 H, s, OMe), 2.56 (3 H, s, Me); δ C (75 MHz; CDCl 3 ) 158.4 (C), 156.2 (C), 154.9 (C), 122.5 (C), 120.2 (CH), 110.5 (CH), 101.3 (CH), 55.9 (Me), 10.1 (Me); m/z (CI) 164 (MH + , 100%), 148 (5).…”

Xanthones in Heterocyclic Synthesis. An Efficient Route for the Synthesis of C-3 o-Hydroxyaryl Substituted 1,2-Benzisoxazoles and Their N-Oxides, Potential Scaffolds for Angiotensin(II) Antagonist Hybrid Peptides

“…13 Arylation of 2c. Reagents were used as commercially purchased while solvents such as CH 2 Cl 2 , EtOAc, hexane and Hz, 3.2 Hz, 2H).…”

“…7.86-7.76 (m, 2H). 13 29. The method described above was repeated and 2,7-diphenylxanthone 2e was obtained.…”

“…They involve, either cyclodehydration of o-hydroxyaryl aldo/ketoximes, triggered by PPh 3 /DDQ, 10 TsCl/ i Pr 2 NEt, 11 microwave in an ionic liquid 12 or CuI/DMEDA/ t BuONa 13 or a [3+2] cycloaddition of in situ generated nitrile oxides with arynes, 14 all under mild conditions. 21 Accordingly, we have developed and report, herein, an efficient protocol for the synthesis of 3-[ohydroxyaryl] substituted 1,2-benzisoxazoles (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) and their N-oxides (23-34) (Schemes 1 and 2). 15 Derivatives have been recently investigated as inhibitors of LTB 4 binding to human neutrophiles, 16 affinity ligands for serotonergic and dopaminergic receptors, 17 selective inhibitors of acetylcholinesterase 18 or for atypical antipsychotic activity.…”

Pd/Mn Bimetallic Relay Catalysis for Aerobic Aldoxime Dehydration to Nitriles

“…Initially, [10] since benzo [d]isoxazole (2) is a versatile heterocycle used to be obtained by intramolecular coupling of the less available ortho-functionalized aldoximes (1), [11] we envisioned that the non-functionalized aldoximes (3) may be used as promising substrates for direct synthesis of 2 [Eq. (1)] based on recent developments in ortho CÀH activation of organoheteroatom acids from one of us and other groups.…”