synthesis of 5-fluoro-2-oxindole: 4-fluoroaniline was used as the starting material, reacted with chloral hydrate and hydroxylamine hydrochloride to generate 4-fluoroisonitrosoacetanilide, and then cyclized under the action of concentrated sulfuric acid to form the compound 5-fluoroisatin was finally obtained by wolff-kishner-huang minlon reduction to obtain 5-fluoro-2-oxindole with a total yield of 66%.
5-Fluoro-2-oxindole has anti-inflammatory, antioxidant, anxiolytic, antidepressant and antinociceptive effects and inhibits neuropathic pain. Treatment with 5-Fluoro-2-oxindole increased the expression of NQO1, HO-1, and MOR in the spinal cord and/or paw and inhibited CFA-induced up-regulation of phosphorylated MAPK, 4-HNE, NOS2, CD11b/c, and IBA-1. 5-Fluoro-2-oxindole ameliorated the local effects of morphine. Studies have revealed that 5-fluoro-2-oxindole inhibits plasticity, oxidative and inflammatory responses induced by peripheral inflammation and enhances the antinociceptive effects of morphine. Thus, the use of 5-fluoro-2-indole alone and/or in combination with morphine are two remarkable new approaches for the treatment of chronic inflammatory pain.