2-bromo-3-methylbutanoyl chloride

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: To a mixture of 2-aminophenol (27 25 g), sodium hydrogencarbonate (31.5 g), ethyl acetate (250 ml), and water (200 ml), a solution of 2-bromo-3-methylbutyryl chloride (49.8 g) in ethyl acetate (100 ml) was added dropwise with ice-cooling and with stirring. After stirring with ice-cooling for further 1 hour, the ethyl acetate layer was separated, washed with water, and dried (MgSO4), and the solvent was evaporated off. The residue was crystallized from hexane, to give 2-(2-bromo-3-methylbutyryl)aminophenol. Yield was 59.7 g (87.9%). Recrystallization from isopropyl ether gave colorless prisms, mp 110°-111° C. cooling After stirring with ice- cooling for further 1 hour the ethyl acetate layer was separated washed with water dried (MgSO4) the solvent was evaporated off The residue was crystallized from hexane

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: Racemic body α-bromoisovaleryl chloride (327 mg, 1.64 mmol) on the market and 4-(N,N-dimethylamino)pyridine (about 10 mg) were added to a pyridine (8 ml) suspension of 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline hydrochloride (472 mg, 2.05 mmol), and the mixture was stirred at room temperature for 3 hours. The reaction solution was diluted with chloroform (50 ml), washed with 1 N hydrochloric acid (50 ml) and a 1 N aqueous sodium hydroxide solution (50 ml), dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and used, without isolating and purifying the obtained gummy substance, in the reactions in Examples 27 and 28. washed with 1 N hydrochloric acid (50 ml) a 1 N aqueous sodium hydroxide solution (50 ml), dried over anhydrous magnesium sulfate concentrated under reduced pressure without isolating purifying the obtained gummy substance

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

Procedure: Into a 500 ml four-necked flask, there were charged methylisobutylketone (150 ml), α,α-dimethylbenzylamine (27.0 g) and triethylamine (21.2 g), and α-bromo-isovaleryl chloride (40.0 g) was dropwise added thereto while stirring at room temperature. Stirring was continued for 3 hours. After completion of the reaction, water (200 ml) was added thereto and the reaction mixture was gradually heated to remove methylisobutylketone, followed by cooling at room temperature. The precipitated crystals were filtered, washed with water, dried and recrystallized from ethanol to give N-(α,α-dimethylbenzyl)-α-bromo-isovaleramide (51.9 g). was dropwise added Stirring was added the reaction mixture was gradually heated to remove methylisobutylketone by cooling at room temperature The precipitated crystals were filtered washed with water dried recrystallized from ethanol

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

Procedure: Into a 200 ml four necked flask, there were charged benzene (100 ml), α,α-dimethylbenzylamine (9 g) and triethylamine (7.4 g), and α-bromo-isovaleryl chloride (13.3 g) was dropwise added thereto while stirring at room temperature. Stirring was continued for 3 hours. The reaction mixture was washed with water to remove triethylamine hydrochloride. After the benzene layer was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. The obtained residue was recrystallized from ethanol to give 16.9 g of N-(α,α-dimethylbenzyl)-α-bromo-isovaleramide. M.P., 128°-129.5° C. was dropwise added Stirring The reaction mixture was washed with water to remove triethylamine hydrochloride After the benzene layer was dried over anhydrous sodium sulfate the solvent was distilled off under reduced pressure The obtained residue was recrystallized from ethanol

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

Procedure: To a mixture of 2-aminophenol (27 25 g), sodium hydrogencarbonate (31.5 g), ethyl acetate (250 ml), and water (200 ml), a solution of 2-bromo-3-methylbutyryl chloride (49.8 g) in ethyl acetate (100 ml) was added dropwise with ice-cooling and with stirring. After stirring with ice-cooling for further 1 hour, the ethyl acetate layer was separated, washed with water, and dried (MgSO4), and the solvent was evaporated off. The residue was crystallized from hexane, to give 2-(2-bromo-3-methylbutyryl)aminophenol. Yield was 59.7 g (87.9%). Recrystallization from isopropyl ether gave colorless prisms, mp 110°-111° C. cooling After stirring with ice- cooling for further 1 hour the ethyl acetate layer was separated washed with water dried (MgSO4) the solvent was evaporated off The residue was crystallized from hexane