ethyl 7-bromo-1H-indole-2-carboxylate

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 11.0 g 2-bromophenylhydrazine and 550 mg p-toluenesulphonic acid monohydrate are dissolved in 200 ml of toluene, combined with 6.74 ml ethyl pyruvate and refluxed for 2 hours using the water separator. The mixture is allowed to cool to 40° C. and combined with a solution that is obtained by dissolving 44.75 g p-toluenesulphonic acid monohydrate in 300 ml of toluene and refluxing for two hours using the water separator. Then the mixture is refluxed for 12 hours using the water separator. After cooling to ambient temperature the solvents are eliminated in vacuo, the residue is taken up in ethyl acetate and washed successively with water and saturated aqueous sodium hydrogen carbonate solution. After drying with magnesium sulphate the mixture is combined with activated charcoal, stirred for 15 minutes and filtered through kieselguhr. The process of adding activated charcoal, stirring and filtering is repeated twice more. The solvents are eliminated in vacuo and the residue is taken up in petroleum ether/dichloromethane 7:3. 30 g of silica gel are added, the mixture is stirred for 10 minutes and then suction filtered through kieselguhr. The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3. The solvents are eliminated in vacuo. refluxed for 2 hours is obtained refluxing for two hours Then the mixture is refluxed for 12 hours After cooling to ambient temperature the solvents washed successively with water and saturated aqueous sodium hydrogen carbonate solution After drying with magnesium sulphate the mixture filtered through kieselguhr The process of adding activated charcoal stirring filtering 30 g of silica gel are added the mixture is stirred for 10 minutes suction filtered through kieselguhr The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 11.0 g 2-bromophenylhydrazine and 550 mg p-toluenesulphonic acid monohydrate are dissolved in 200 ml of toluene, combined with 6.74 ml ethyl pyruvate and refluxed for 2 hours using the water separator. The mixture is allowed to cool to 40° C. and combined with a solution that is obtained by dissolving 44.75 g p-toluenesulphonic acid monohydrate in 300 ml of toluene and refluxing for two hours using the water separator. Then the mixture is refluxed for 12 hours using the water separator. After cooling to ambient temperature the solvents are eliminated in vacuo, the residue is taken up in ethyl acetate and washed successively with water and saturated aqueous sodium hydrogen carbonate solution. After drying with magnesium sulphate the mixture is combined with activated charcoal, stirred for 15 minutes and filtered through kieselguhr. The process of adding activated charcoal, stirring and filtering is repeated twice more. The solvents are eliminated in vacuo and the residue is taken up in petroleum ether/dichloromethane 7:3. 30 g of silica gel are added, the mixture is stirred for 10 minutes and then suction filtered through kieselguhr. The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3. The solvents are eliminated in vacuo. refluxed for 2 hours is obtained refluxing for two hours Then the mixture is refluxed for 12 hours After cooling to ambient temperature the solvents washed successively with water and saturated aqueous sodium hydrogen carbonate solution After drying with magnesium sulphate the mixture filtered through kieselguhr The process of adding activated charcoal stirring filtering 30 g of silica gel are added the mixture is stirred for 10 minutes suction filtered through kieselguhr The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 11.0 g 2-bromophenylhydrazine and 550 mg p-toluenesulphonic acid monohydrate are dissolved in 200 ml of toluene, combined with 6.74 ml ethyl pyruvate and refluxed for 2 hours using the water separator. The mixture is allowed to cool to 40° C. and combined with a solution that is obtained by dissolving 44.75 g p-toluenesulphonic acid monohydrate in 300 ml of toluene and refluxing for two hours using the water separator. Then the mixture is refluxed for 12 hours using the water separator. After cooling to ambient temperature the solvents are eliminated in vacuo, the residue is taken up in ethyl acetate and washed successively with water and saturated aqueous sodium hydrogen carbonate solution. After drying with magnesium sulphate the mixture is combined with activated charcoal, stirred for 15 minutes and filtered through kieselguhr. The process of adding activated charcoal, stirring and filtering is repeated twice more. The solvents are eliminated in vacuo and the residue is taken up in petroleum ether/dichloromethane 7:3. 30 g of silica gel are added, the mixture is stirred for 10 minutes and then suction filtered through kieselguhr. The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3. The solvents are eliminated in vacuo. refluxed for 2 hours is obtained refluxing for two hours Then the mixture is refluxed for 12 hours After cooling to ambient temperature the solvents washed successively with water and saturated aqueous sodium hydrogen carbonate solution After drying with magnesium sulphate the mixture filtered through kieselguhr The process of adding activated charcoal stirring filtering 30 g of silica gel are added the mixture is stirred for 10 minutes suction filtered through kieselguhr The suction filtered silica gel is washed with petroleum ether/dichloromethane 7:3

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7.37 g ethyl 7-bromo-1H-indole-2-carboxylate are dissolved in 50 ml N,N-dimethylformamide, cooled to 0° C. and combined with 1.16 g sodium hydride (60% in mineral oil). The mixture is stirred for 20 minutes and then 1.78 ml methyl iodide are added dropwise. Then the mixture is allowed to come up to ambient temperature and stirred for 12 hours. Then 80 ml of methanol and 27.5 ml 2 N sodium hydroxide solution are added and the mixture is stirred for 3 hours at ambient temperature. The methanol is eliminated in vacuo, the residue is mixed with water and the precipitate is suction filtered. The filtrate is washed twice with ethyl acetate and the aqueous phase is combined with sufficient 2 N hydrochloric acid to give a pH of 2. The precipitated solid is suction filtered, washed with water and dried. to come up to ambient temperature stirred for 12 hours the mixture is stirred for 3 hours at ambient temperature filtered The filtrate is washed twice with ethyl acetate to give a pH of 2 filtered washed with water dried

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 7.37 g ethyl 7-bromo-1H-indole-2-carboxylate are dissolved in 50 ml N,N-dimethylformamide, cooled to 0° C. and combined with 1.16 g sodium hydride (60% in mineral oil). The mixture is stirred for 20 minutes and then 1.78 ml methyl iodide are added dropwise. Then the mixture is allowed to come up to ambient temperature and stirred for 12 hours. Then 80 ml of methanol and 27.5 ml 2 N sodium hydroxide solution are added and the mixture is stirred for 3 hours at ambient temperature. The methanol is eliminated in vacuo, the residue is mixed with water and the precipitate is suction filtered. The filtrate is washed twice with ethyl acetate and the aqueous phase is combined with sufficient 2 N hydrochloric acid to give a pH of 2. The precipitated solid is suction filtered, washed with water and dried. to come up to ambient temperature stirred for 12 hours the mixture is stirred for 3 hours at ambient temperature filtered The filtrate is washed twice with ethyl acetate to give a pH of 2 filtered washed with water dried

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

Procedure: A solution of 8.1 g (30.1 mmol) 7-bromo-1H-indole-2-carboxylic acid ethyl ester in 120 ml N,N-dimethylformamide was cooled to 0° C. and 3.55 g (31.6 mmol) potassium tert-butoxide was added. After 30 min., 7.86 g (33.1 mmol) (S)-5-methyl-2,2-dioxo-[1,2,3]oxathiazolidine-3-carboxylic acid tert-butyl ester were added and the cooling bath was removed. After 20 h the reaction mixture was poured on 10% aqueous citric acid solution and ethyl acetate. The organic layer was dried over magnesium sulfate, filtered and evaporated. The resulting yellow oil was chromatographed on silica gel (0.032-0.063 mm) with tert-butyl methyl ether: n-hexane (1:8) as eluant to give the desired compound as a yellow oil. ISP-MS: m/e=427.3 ([M+H+]). the cooling bath was removed After 20 h the reaction mixture was poured on 10% aqueous citric acid solution and ethyl acetate The organic layer was dried over magnesium sulfate filtered evaporated The resulting yellow oil was chromatographed on silica gel (0.032-0.063 mm) with tert-butyl methyl ether: n-hexane (1:8) as eluant