tert-butyl 2-aminopentanoate

Conditions: temp:70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In DMF (5.0 ml) was dissolved tert-butyl 4-methyl-aminobutyrate (1050 mg), and to the mixture was added at room temperature a solution of 5-bromo-2-fluorobenzaldehyde (1025 mg) in DMF (1.0 ml) and then potassium carbonate (837 mg). The mixture was stirred at 70° C. for 60 hours, and to the mixture was added at room temperature water (50 ml). The mixture was extracted with ethyl acetate (50 ml×3), and the organic layer was washed with saturated brine (50 ml×3) and dried with anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified with silica gel column chromatography (75 g, hexane:ethyl acetate=10:1) to give tert-butyl 4-(4-bromo-2-formyl-N-methylanilino)butyrate (1620 mg, 90%). The mixture was extracted with ethyl acetate (50 ml×3) the organic layer was washed with saturated brine (50 ml×3) dried with anhydrous magnesium sulfate The solvent was evaporated under reduced pressure the residue was purified with silica gel column chromatography (75 g, hexane:ethyl acetate=10:1)