Reaction #9377

Reaction equation

AlCl3

3-(2-bromo-phenyl)-propionic acid

oxalyl chloride

→

4-Bromoindan-1-one

Solvents

CH2Cl2

Conditions

Workup

1. 1
   ConcentrationAs the mixture was concentrated
2. 2
   workup.DISSOLUTIONthe residue was dissolved in CH2Cl2
3. 3
   OtherAfter 1 h the mixture was quenched with water
4. 4
   Otherthe layers were separated
5. 5
   ExtractionThe aqueous layer was extracted with Et2O (3×150 mL)
6. 6
   Washthe combined organic extracts were washed with H2O (3×100 mL), saturated NaHCO3 (3×100 mL), brine (1×100 mL)
7. 7
   Dryingdried over MgSO4
8. 8
   Concentrationconcentrated

Procedure

4-Bromo-indan-1-one was obtained by the following procedure: A solution of 3-(2-bromo-phenyl)-propionic acid (commercially available from Oakwood Products) (15.0 g, 65.5 mmol) in CH2Cl2 at 0° C. was reacted with oxalyl chloride (7.2 mL, 1.5 eq) followed by 2–3 drops of DMF. The mixture was stirred until no more gas evolution was observed. As the mixture was concentrated and the residue was dissolved in CH2Cl2, cooled to 0° C., and treated with AlCl3 (9.6 g, 1.1 eq). After 1 h the mixture was quenched with water and the layers were separated. The aqueous layer was extracted with Et2O (3×150 mL) and the combined organic extracts were washed with H2O (3×100 mL), saturated NaHCO3 (3×100 mL), brine (1×100 mL), dried over MgSO4 and concentrated. 4-Bromoindan-1-one, 10.5 g (76%) was obtained by chromatography using 10% EtOAc:hexane as eluant. Use of 4-bromo-indan-1-one in Method NINETEEN produced 4-(4-bromo-indan-2-yl)-1,3-dihydro-imidazole-2-thione (Compound 149).

Source