Reaction #7092

Reaction equation

sodium hydrogen carbonate

spiro[cyclopentane-1,3′-[3H]indol]-2′(1′H)-one

sodium acetate

bromine

→

subtitled compound

Yield 105.0%

5-Bromo-spiro[cyclopentane-1,3′-[3H]indol]-2′(1′H)-one

Yield 105.0%

Solvents

acetic acid

acetic acid

Conditions

Workup

1. 1
   Extractionextracted with EtOAc (×2)
2. 2
   Washthe combined organic layers were washed with water, sat. sodium hydrogen carbonate solution, water
3. 3
   Dryingdried (MgSO4)
4. 4
   Otherevaporated

Procedure

A solution of spiro[cyclopentane-1,3′-[3H]indol]-2′(1′H)-one (0.27 g, 1.4 mmol) and sodium acetate (0.12 g, 1.46 mmol) in acetic acid (10 cm3) was treated with bromine (0.24 g, 1.51 mmol) in acetic acid (2 cm3). After 30 min. the mixture was poured into sat. sodium hydrogen carbonate solution and extracted with EtOAc (×2), the combined organic layers were washed with water, sat. sodium hydrogen carbonate solution, water, dried (MgSO4), and evaporated to give the subtitled compound (0.37 g, 1.47 mmol, 96%) as an off-white solid which was used without further purification: 1H NMR (CDCl3) δ 1.8–2.27 (m, 8H), 6.79 (d, J=8 Hz, 1H), 7.30–7.39 (m, 2H), 8.63 (br s, 1H).

Source