ethyl 4-chloro-7-fluoro-1H-indole-2-carboxylate

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

Procedure: The title compound, ISP-MS: m/e=399.4 (M+H+) and αD20=−54.7, was prepared in accordance with the general method of example 12b) from 4-chloro-7-fluoro-1H-indole-2-carboxylic acid ethyl ester and (S)-5-methyl-2,2-dioxo-[1,2,3]oxathiazolidine-3-carboxylic acid tert-butyl ester.

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

Procedure: 2-[(5-Chloro-2-fluoro-phenyl)-hydrazono]-propionic acid ethyl ester (13.2 g, 51 mmol) was dissolved in toluene, p-toluenesulfonic acid (10 g, 51 mmol) was added and the mixture was heated to reflux for 24 h with separation of water. The mixture was cooled, neutralized with saturated sodium bicarbonate (400 mL) and extracted thrice with ethyl acetate. Organic phases were pooled, washed with brine, dried with MgSO4 and the solvent was removed in vacuo. The residue was triturated with hexane to yield the title product as yellowish solid (2.9 g, 23%); EI-MS: m/e=241.1 (M+). the mixture was heated The mixture was cooled extracted thrice with ethyl acetate washed with brine dried with MgSO4 the solvent was removed in vacuo The residue was triturated with hexane

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

Procedure: The title compound, ISP-MS: m/e=399.4 (M+H+) and α D 20 = - 54.7 , was prepared in accordance with the general method of example 12b) from 4-chloro-7-fluoro-1H-indole-2-carboxylic acid ethyl ester and (S)-5-methyl-2,2-dioxo-[1,2,3]oxathiazolidine-3-carboxylic acid tert-butyl ester. e) (R)-9-Chloro-6-fluoro-4-methyl-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one

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

Procedure: 2-[(5-Chloro-2-fluoro-phenyl)-hydrazono]-propionic acid ethyl ester (13.2 g, 51 mmol) was dissolved in toluene, p-toluenesulfonic acid (10 g, 51 mmol) was added and the mixture was heated to reflux for 24 h with separation of water. The mixture was cooled, neutralized with saturated sodium bicarbonate (400 mL) and extracted thrice with ethyl acetate. Organic phases were pooled, washed with brine, dried with MgSO4 and the solvent was removed in vacuo. The residue was triturated with hexane to yield the title product as yellowish solid (2.9 g, 23%); EI-MS: m/e=241.1 (M+). the mixture was heated The mixture was cooled extracted thrice with ethyl acetate washed with brine dried with MgSO4 the solvent was removed in vacuo The residue was triturated with hexane

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

Procedure: 2-[(5-Chloro-2-fluoro-phenyl)-hydrazono]-propionic acid ethyl ester (13.2 g, 51 mmol) was dissolved in toluene, p-toluenesulfonic acid (10 g, 51 mmol) was added and the mixture was heated to reflux for 24 h with separation of water. The mixture was cooled, neutralized with saturated sodium bicarbonate (400 mL) and extracted thrice with ethyl acetate. Organic phases were pooled, washed with brine, dried with MgSO4 and the solvent was removed in vacuo. The residue was triturated with hexane to yield the title product as yellowish solid (2.9 g, 23%); EI-MS: m/e=241.1 (M+). the mixture was heated The mixture was cooled extracted thrice with ethyl acetate washed with brine dried with MgSO4 the solvent was removed in vacuo The residue was triturated with hexane

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

Procedure: The title compound, ISP-MS: m/e=399.4 (M+H+) and αD20=−54.7, was prepared in accordance with the general method of example 12b) from 4-chloro-7-fluoro-1H-indole-2-carboxylic acid ethyl ester and (S)-5-methyl-2,2-dioxo-[1,2,3]oxathiazolidine-3-carboxylic acid tert-butyl ester.

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

Procedure: 2-[(5-Chloro-2-fluoro-phenyl)-hydrazono]-propionic acid ethyl ester (13.2 g, 51 mmol) was dissolved in toluene, p-toluenesulfonic acid (10 g, 51 mmol) was added and the mixture was heated to reflux for 24 h with separation of water. The mixture was cooled, neutralized with saturated sodium bicarbonate (400 mL) and extracted thrice with ethyl acetate. Organic phases were pooled, washed with brine, dried with MgSO4 and the solvent was removed in vacuo. The residue was triturated with hexane to yield the title product as yellowish solid (2.9 g, 23%); EI-MS: m/e=241.1 (M+). the mixture was heated The mixture was cooled extracted thrice with ethyl acetate washed with brine dried with MgSO4 the solvent was removed in vacuo The residue was triturated with hexane

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

Procedure: The title compound, ISP-MS: m/e=399.4 (M+H+) and α D 20 = - 54.7 , was prepared in accordance with the general method of example 12b) from 4-chloro-7-fluoro-1H-indole-2-carboxylic acid ethyl ester and (S)-5-methyl-2,2-dioxo-[1,2,3]oxathiazolidine-3-carboxylic acid tert-butyl ester. e) (R)-9-Chloro-6-fluoro-4-methyl-3,4-dihydro-2H-pyrazino[1,2-a]indol-1-one

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

Procedure: 2-[(5-Chloro-2-fluoro-phenyl)-hydrazono]-propionic acid ethyl ester (13.2 g, 51 mmol) was dissolved in toluene, p-toluenesulfonic acid (10 g, 51 mmol) was added and the mixture was heated to reflux for 24 h with separation of water. The mixture was cooled, neutralized with saturated sodium bicarbonate (400 mL) and extracted thrice with ethyl acetate. Organic phases were pooled, washed with brine, dried with MgSO4 and the solvent was removed in vacuo. The residue was triturated with hexane to yield the title product as yellowish solid (2.9 g, 23%); EI-MS: m/e=241.1 (M+). the mixture was heated The mixture was cooled extracted thrice with ethyl acetate washed with brine dried with MgSO4 the solvent was removed in vacuo The residue was triturated with hexane