(6,7-dichloro-2,3-dihydro-1-benzofuran-2-yl)methanol

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2 × 150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2 × 150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2 × 150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2 × 150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

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

Procedure: To a solution of 2.88 g of 6,7-dichloro-2-hydroxymethyl-2,3-dihydrobenzofuran dissolved in 22 ml of DMF is added 790 mg of sodium hydride (50% suspension) and stirred at room temperature for 30 minutes. After addition of 1.73 g of ethyl bromide, the reaction mixture is stirred at room temperature for 17 hours and extracted with water and ether. The ether layer is washed with water, dried over magensium sulfate, and evaporated under reduced pressure to give a residue, which is chromatographed on silica gel with dichloromethane as an eluent to give 2.0 g of oily 6,7-dichloro-2-ethoxymethyl-2,3-dihydrobenzofuran. To a solution of 2.0 g of the 6,7-dichloro-2-ethoxymethyl-2,3-dihydrobenzofuran dissolved in 5 ml of thionyl chloride is dropwise added 3 g of chlorosulfonic acid under ice-cooling. The reaction mixture is stirred at room temperature for 2 hours, then poured into iced water, and extracted with ethyl acetate. The ethyl acetate layer is washed with water, dried and evaporated under reduced pressure to give an oil, which is then dissolved in 30 ml of dichloromethane. After introduction of 30 ml of ammonia at -30° to -20° C., the mixture is allowed to stand at room temperature for a night and evaporated under reduced pressure to give an oily residue, which is then dissolved in ethyl acetate and washed with water. The ethyl acetate layer is dried and evaporated to dryness to give 2.7 g of an oily product, which is chromatographed on silica gel with dichloromethane (1000 ml) and successively dichloromethane/acetone (20/1) as eluents to give 900 mg of the objective 6,7-dichloro-2-ethoxymethyl-5-sulfamoyl-2,3-dihydrobenzofuran (I j-84) as crystals, yield 24%, m.p. 148°-149° C. the reaction mixture is stirred at room temperature for 17 hours extracted with water and ether The ether layer is washed with water dried over magensium sulfate evaporated under reduced pressure to give a residue, which is chromatographed on silica gel with dichloromethane as an eluent

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2×150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2×150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2 × 150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2 × 150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid

Conditions: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 6,7-dichloro-2,3-dihydro-2-hydroxymethylbenzofuran (10.4 gm.) in acetone (200 ml.) cooled to 20° C. is added an oxidizing solution prepared from chromium trioxide (6.0 g.), concentrated sulfuric acid (5.3 ml.) and water (43 ml.) over a one-half hour period. The reaction mixture is stirred at 25° C. for 18 hours. The acetone layer is separated from the precipitated chromium salts, added to water (600 ml.) and extracted with ether (2 × 150 ml.). The ether extract is washed with water then extracted with aqueous sodium bicarbonate. Acidification of the basic solution gives 3.4 g. of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid. is added an oxidizing solution The acetone layer is separated from the precipitated chromium salts added to water (600 ml.) extracted with ether (2 × 150 ml.) The ether extract is washed with water then extracted with aqueous sodium bicarbonate Acidification of the basic solution gives 3.4 g of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid which is purified by reprecipitation from aqueous sodium hydroxide with aqueous hydrochloric acid