4-bromo-1,3-dihydroindol-2-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-bromooxindole (2.77 g, 0.01 mol) and a solution of BH3 in THF (2 M, 40 mL) was stirred at room temperature overnight. The mixture was cooled to 0° C. and diluted with 30 mL of methanol, followed by addition of 12 N HCl (7.5 mL). The resulting mixture was stirred at room temperature for 1 hour, adjusted to pH 8-9 with 10% aqueous NaOH. Water was added to the mixture and extracted with ethyl acetate (3×100 mL). The organic layer was dried and concentrated to get the crude product which was washed through a silica gel column (ethyl acetate in petroleum ether (10%). The crude product was dissolved in 10% HCl (3×10 mL). The aqueous layer was adjusted to pH7 with NaHCO3, extracted with ethyl acetate (3×20 mL). The organic layer was dried and concentrated to get 4-bromoindoline (1.16 g, 45%) as an oil. LCMS: 200 [M+1]+. 1H-NMR (400 MHz. DMSO-d6) δ 2.90 (t, J=8.8 Hz, 2H), 3.46 (t, J=8.8 Hz, 2H), 5.86 (s, 1H), 6.43 (m, 1H), 6.64 (m, 1H), 6.83 (t, J=8.0 Hz, 1H). extracted with ethyl acetate (3×100 mL) The organic layer was dried concentrated to get the crude product which was washed through a silica gel column (ethyl acetate in petroleum ether (10%) The crude product was dissolved in 10% HCl (3×10 mL) extracted with ethyl acetate (3×20 mL) The organic layer was dried concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of concentrated sulfuric acid (3.6 mL) and concentrated nitric acid (0.7 mL) was added slowly to a solution of 4-bromo-1,3-dihydro-2H-indol-2-one (2 g, 9.48 mmol) (see Kosuge et al., supra) in concentrated sulfuric acid (20 mL) at −5° C. with stirring. The mixture was stirred for an additional 1 h at −5° C. then poured into ice. After standing for 1 h, precipitate formed was collected by filtration and washed with water, and dried in a vacuum oven to give the above product. (Yield 2.33 g, 96%). The mixture was stirred for an additional 1 h at −5° C. then poured into ice precipitate formed was collected by filtration washed with water dried in a vacuum oven to give the above product

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4-bromo-1,3-dihydro-2H-indol-2-one (0.2 g, 0.94 mmol) (see Kosuge et al., supra), and excess pyrrole-2-carboxaldehyde (0.11 g, 1.13 mmol) (Aldrich) in 1% piperidine in 2-propanol (2 mL) was heated at 85° C. for 2 h. Hot water (2 mL) was added. On cooling, the crystallized product was filtered off, washed with aqueous 2-propanol and dried. (Yield 0.26 g, 96%). On cooling the crystallized product was filtered off washed with aqueous 2-propanol dried

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of concentrated sulfuric acid (3.6 mL) and concentrated nitric acid (0.7 mL) was added slowly to a solution of 4-bromo-1,3-dihydro-2H-indol-2-one (2 g, 9.48 mmol) (see below) in concentrated sulfuric acid (20 mL) at −5° C. with stirring. The mixture was stirred for an additional 1 h at −5° C. then poured in ice. After standing for 1 h, precipitate formed was collected by filtration and washed with water, and dried in a vacuum oven to give 4-bromo-1,3-dihydro-5-nitro-2H-indol-2-one. (Yield 2.33 g, 96%). The mixture was stirred for an additional 1 h at −5° C. then poured in ice precipitate formed was collected by filtration washed with water dried in a vacuum oven