5-Bromo-1,3-dihydro-1-methyl-2H-indol-2-one

N-methyloxindole (0.5 g, 3.4 mmol) in acetonitrile(5 mL) was stirred at 0C, and then NBS (0.62 g) in 10 mL acetonitrile was added dropwise. The mixture was stirred at that temperature for 1h and then stirred for 2h at ambienttemperature. Then the solution was evaporated and the solid was dissolved in CHCl3, washed twice with water. After CHCl3 was evaporated, the brown solid was recrystallizedwith hexane. 5-bromo-N-methyloxindole (0.44 g) was prepared in 58percent yield.1H-NMR (300MHz, CDCl3) δ(ppm) : 7.42–7.39 (d, 1H), 7.26 (s, 1H), 6.71–6.68 (d, 1H), 3.52–3.20 (s, 2H), 3.19 (s, 3H).Add 0.4 mL of 1, 4-dioxane to a 50 mL reaction tube at room temperature.Add 2 mL of water and mix by stirring.Weighing 1-fluoro-1, 2-phenyliodohydrin-3-(1H)-one (175 mg, 0.66 mmol) was added to the reaction tube and stirred for 1 min.After the reaction tube was placed in a 140 ° C oil bath, 5-bromo-N-methyl hydrazine (121 mg, 0.6 mmol) was added.A built-in condenser was added and reacted in a 140 ° C oil bath for 5 hours.The TLC dot plate shows that the raw material reaction is complete, Take the reaction tube out of the oil bath.Cool to room temperature, The reaction was quenched by the addition of 10 mL of saturated sodium bicarbonate.It was extracted with ethyl acetate (20 mL).The organic layer is concentrated by steaming, The pale pink solid 5-bromo-N-methyl-substituted 2-indolone 124 mg was obtained by column chromatography, yield 91percent.General procedure: A mixture of oxindole 1 (0.30 mmol), allenoate 2 (0.75 mmol), PPh3 (0.045 mmol) in xylene (2.0 mL, dried over 4 A MS) was stirred at 50 C under Ar atmosphere for 24 h. After completion of the reaction (indicated by TLC), the mixture was quenched with saturated NaCl solution and diluted with EtOAc, followed by washing with H2O and saturated NaCl solution, and finally dried over Na2SO4. The crude product was purified by flash column chromatography to provide the corresponding product 3.General procedure: A mixture of oxindole 1 (0.30 mmol), allenoate 2 (0.75 mmol), PPh3 (0.045 mmol) in xylene (2.0 mL, dried over 4 A MS) was stirred at 50 C under Ar atmosphere for 24 h. After completion of the reaction (indicated by TLC), the mixture was quenched with saturated NaCl solution and diluted with EtOAc, followed by washing with H2O and saturated NaCl solution, and finally dried over Na2SO4. The crude product was purified by flash column chromatography to provide the corresponding product 3.General procedure: A mixture of oxindole 1 (0.30 mmol), allenoate 2 (0.75 mmol), PPh3 (0.045 mmol) in xylene (2.0 mL, dried over 4 A MS) was stirred at 50 C under Ar atmosphere for 24 h. After completion of the reaction (indicated by TLC), the mixture was quenched with saturated NaCl solution and diluted with EtOAc, followed by washing with H2O and saturated NaCl solution, and finally dried over Na2SO4. The crude product was purified by flash column chromatography to provide the corresponding product 3.

Molecular Weight:226.07
XLogP3:1.6
Hydrogen Bond Acceptor Count:1
Exact Mass:224.97893
Monoisotopic Mass:224.97893
Topological Polar Surface Area:20.3
Heavy Atom Count:12
Complexity:207
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes