5-fluoro-1-benzofuran-3-one

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

Procedure: To a stirred solution of TiCl4 (1M solution in CH2Cl2, 7 ml) and 5-fluoro-benzofuran -3-one (Cagniant, et al., Comptus Rendus des Seances Acad. de Sci., Ser. C, 282:993 (1976), 3.0 g) (3.0 g, 19.7 mmol) in methylene chloride (200 ml) at −10° C., ethyl-1-piperizine carboxylate (commercially available) (3.9 g, 35 mmol) was slowly added. After the addition, the reaction mixture was warmed to room temperature and slowly refluxed for 24 hours. After cooling to room temperature, the reaction was quenched with 2 N aqueous HCl. The organic layer was separated and the aqueous layer was extracted with chloroform. The combined organic layers were washed well with water and dried over anhydrous MgSO4, then filtered and concentrated resulting in a brown oil. Yield: 3.5 g, (60%); MS (ESI) m/z 293 [M+−H]+. After the addition slowly refluxed for 24 hours After cooling to room temperature the reaction was quenched with 2 N aqueous HCl The organic layer was separated the aqueous layer was extracted with chloroform The combined organic layers were washed well with water dried over anhydrous MgSO4 filtered concentrated resulting in a brown oil

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

Procedure: To a stirred solution of TiCl4 (1M solution in CH2Cl2, 7 ml) and 5-fluoro-benzofuran -3-one (Cagniant, et al., Comptus Rendus des Seances Acad. de Sci., Ser. C, 282:993 (1976), 3.0 g) (3.0 g, 19.7 mmol) in methylene chloride (200 ml) at −10° C., ethyl-1-piperizine carboxylate (commercially available) (3.9 g, 35 mmol) was slowly added. After the addition, the reaction mixture was warmed to room temperature and slowly refluxed for 24 hours. After cooling to room temperature, the reaction was quenched with 2 N aqueous HCl. The organic layer was separated and the aqueous layer was extracted with chloroform. The combined organic layers were washed well with water and dried over anhydrous MgSO4, then filtered and concentrated resulting in a brown oil. Yield: 3.5 g, (60%); MS (ESI) m/z 293 [M+−H]+. After the addition slowly refluxed for 24 hours After cooling to room temperature the reaction was quenched with 2 N aqueous HCl The organic layer was separated the aqueous layer was extracted with chloroform The combined organic layers were washed well with water dried over anhydrous MgSO4 filtered concentrated resulting in a brown oil

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

Procedure: A mixture of 5-fluoro-benzofuran-3 (2H)-one (1.52 g, 10 mmol) and (carboxymethylene)triphenylphosphorane (5.22 g, 15 mmol) was refluxed in toluene (100 ml) for 48 hrs. At the end, reaction mixture was concentrated and loaded over a silica-gel column. The column was eluted with hexane (500 ml) and later with 25% ethyl acetate. The product, ethyl(5-fluoro-1-benzofuran-3-yl)acetate, was obtained as a white oil. Yield: 1.8 g (80%); 223 (M+H). At the end, reaction mixture was concentrated The column was eluted with hexane (500 ml) and later with 25% ethyl acetate

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

Procedure: A mixture of 5-fluoro-benzofuran-3 (2H)-one (1.52 g, 10 mmol) and (carboxymethylene)triphenylphosphorane (5.22 g, 15 mmol) was refluxed in toluene (100 ml) for 48 hrs. At the end, reaction mixture was concentrated and loaded over a silica-gel column. The column was eluted with hexane (500 ml) and then with 25% ethyl acetate. The product, ethyl(5-fluoro-1-benzofuran-3-yl)acetate, was obtained as a white oil. Yield: 1.8 g (80%); (M+H): 223. At the end, reaction mixture was concentrated The column was eluted with hexane (500 ml)