Chlorosuccinimide → HCID 20351113, compound

Participants

Reaction Steps

A solution of 3-methylthio-4-nitrooxindole (1.58 g, 7 mmol) and N-chlorosuccinimide (1.20 g, 9 mmol) in 100 ml of methylene chloride was stirred at room temperature for 48 hours. The solvent was removed in vacuo, yielding crude 3-chloro-3-methylthio-4-nitrooxindole. The residue was dissolved in 25 ml of tetrahydrofuran and added rapidly in a vigorously stirred slurry of red mercuric oxide (1.52 g, 7 mmol) and boron trifluoride etherate (1.00 g, 7 mmol) in 100 ml of 50 percent aqueous tetrahydrofuran. After stirring for 3 hours, the solution was filtered through a Celite pad which was then washed with copious amounts of chloroform. The organic layer was separated, dried over anhydrous magnesium sulfate, filtered, and the filtrate was evaporated. The residue was chromatographed on silica gel. Elution with chloroform-ethanol (9:1) gave 4-nitroisatin (535 mg, 40%), mp 248°-250° (dec) (recrystallized from ethanol); ir (KBr) 3200 (NH), 1750 (C=O), 1710 (C=O), 1520 (NO2) and 1350 cm-1 (NO2); nmr (DMSO-d6)τ-1.30 (1H, b s, NH), 2.20-2.80 (m, 3H, aryl H).

Provenance & Evidence