ethyl 5-chloro-1-benzofuran-2-carboxylate

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

Procedure: A solution of ethyl 5-chlorobenzofuran-2-carboxylate (350 mg, 1.56 mmol) in THF (10 ml) is added at −70° C. to a THF solution of lithiated 4-chloropyridine (1.8 mmol prepared according to G. Quéguiner et al., Synthesis 1986, 886-891). The mixture is allowed to reach room temperature within 16 hours before quenching with acetic acid. The product is extracted with chloroform. Drying and chromatography on silicagel gives the title compound. before quenching with acetic acid The product is extracted with chloroform Drying

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

Procedure: A solution of ethyl 5-chlorobenzofuran-2-carboxylate (350 mg, 1.56 mmol) in THF (10 ml) is added at −70° C. to a THF solution of lithiated 4-chloropyridine (1.8 mmol prepared according to G. Quéguiner et al., Synthesis 1986, 886-891). The mixture is allowed to reach room temperature within 16 hours before quenching with acetic acid. The product is extracted with chloroform. Drying and chromatography on silicagel gives the title compound. before quenching with acetic acid The product is extracted with chloroform Drying

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

Procedure: To a suspension of ethyl-5-chloro-benzofuran carboxylate (1.05 g), prepared according to Helv. Chim. Acta., 818 (1935), in tetrahydrofuran (10 ml) was added lithium aluminum hydride (0.1 g). The mixture was stirred at room temperature for 1 hour. Ethyl acetate (50 ml) was slowly added to the reaction mixture, and the whole mixture was poured onto water (50 ml). The organic extract was separated, washed with water (2×25 ml), dried and evaporated to obtain 2-hydroxymethyl-5-cnlorobenzofuran as an oil [0.87 g; 'HNMR (CDCl3, 60 MHz): 4.6 (s, 2H), 6.6-7.4 (m, 4H)]. This material was added to a solution of methanesulfonyl chloride (1.15 g) in methylene chloride (20 ml) containing pyridine (1 ml). After stirring the reaction overnight it was poured onto ice-water (20 ml) and the organic extract was first washed with 10% HCl (5 ml) and then with water (2×10 ml). The washed extract was dried and evaporated to obtain 2-chloromethyl-5-chlorobenzofuran as a clear oil (yield: 0.5 g); HNMR (CDCl3, 60 MHz): 4.65 (s, 2H), 6.6 (s, 1H), 6.8-7.4 (m, 3H). prepared the whole mixture was poured onto water (50 ml) The organic extract was separated washed with water (2×25 ml) dried evaporated to obtain 2-hydroxymethyl-5-cnlorobenzofuran as an oil [0.87 g After stirring the reaction overnight it was poured onto ice-water (20 ml) the organic extract was first washed with 10% HCl (5 ml) The washed extract was dried evaporated

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

Procedure: A solution of ethyl 5-chlorobenzofuran-2-carboxylate (350 mg, 1.56 mmol) in THF (10 ml) is added at −70° C. to a THF solution of lithiated 4-chloropyridine (1.8 mmol prepared according to G. Quéguiner et al., Synthesis 1986, 886-891). The mixture is allowed to reach room temperature within 16 hours before quenching with acetic acid. The product is extracted with chloroform. Drying and chromatography on silicagel gives the title compound. before quenching with acetic acid The product is extracted with chloroform Drying