methyl 2-bromo-3-[(2-methylpropan-2-yl)oxy]propanoate

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The crude N-aryl-benzenesulfonamide building block XIII, e.g. 4-ethoxy-N-(4-methylphenyl)benzenesulfonamide (388 mg, 1.33 mmol, preparation described in example 1, step a)), was dissolved in DMF (5 mL). Intermediate XI with R3═CH2OtBu, e.g. methyl 2-bromo-3-tert-butoxypropanoate (478 mg, 2 mmol) and potassium carbonate (368 mg, 2.66 mmol) were added. The mixture was heated overnight at 60° C. Solvents were evaporated. The crude residue was suspended in ethyl acetate (10 mL) and was washed with 1N HCl solution (7 mL) and with brine (7 mL). Organic phase was dried over MgSO4, fitrated and evaporated. The crude mixture was purified by flash chromatography, using a 8:2 mixture cyclohexane/ethyl acetate as eluent. The desired product, e.g. methyl 3-tert-butoxy-2-{[(4-ethoxyphenyl)sulfonyl]-4-methylanilino}propanoate (157 mg, 26.3%) was isolated as a light yellow oil, in 96.4% purity by HPLC (MaxPlot detection between 230 and 400 nm). Solvents were evaporated was washed with 1N HCl solution (7 mL) and with brine (7 mL) Organic phase was dried over MgSO4 evaporated The crude mixture was purified by flash chromatography

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The crude N-aryl-benzenesulfonamide building block XIII, e.g. 4-ethoxy-N-(4-methylphenyl)benzenesulfonamide (388 mg, 1.33 mmol, preparation described in example 1, step a)), was dissolved in DMF (5 mL). Intermediate XI with R3═CH2OtBu, e.g. methyl 2-bromo-3-tert-butoxypropanoate (478 mg, 2 mmol) and potassium carbonate (368 mg, 2.66 mmol) were added. The mixture was heated overnight at 60° C. Solvents were evaporated. The crude residue was suspended in ethyl acetate (10 mL) and was washed with 1N HCl solution (7 mL) and with brine (7 mL). Organic phase was dried over MgSO4, fitrated and evaporated. The crude mixture was purified by flash chromatography, using a 8:2 mixture cyclohexane/ethyl acetate as eluent. The desired product, e.g. methyl 3-tert-butoxy-2-{[(4-ethoxyphenyl)sulfonyl]-4-methylanilino}propanoate (157 mg, 26.3%) was isolated as a light yellow oil, in 96.4% purity by HPLC (MaxPlot detection between 230 and 400 nm). Solvents were evaporated was washed with 1N HCl solution (7 mL) and with brine (7 mL) Organic phase was dried over MgSO4 evaporated The crude mixture was purified by flash chromatography

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The crude N-aryl-benzenesulfonamide building block XIII, e.g. 4-ethoxy-N-(4-methylphenyl)benzenesulfonamide (388 mg, 1.33 mmol, preparation described in example 1, step a)), was dissolved in DMF (5 mL). Intermediate XI with R3═CH2OtBu, e.g. methyl 2-bromo-3-tert-butoxypropanoate (478 mg, 2 mmol) and potassium carbonate (368 mg, 2.66 mmol) were added. The mixture was heated overnight at 60° C. Solvents were evaporated. The crude residue was suspended in ethyl acetate (10 mL) and was washed with 1N HCl solution (7 mL) and with brine (7 mL). Organic phase was dried over MgSO4, fitrated and evaporated. The crude mixture was purified by flash chromatography, using a 8:2 mixture cyclohexane/ethyl acetate as eluent. The desired product, e.g. methyl 3-tert-butoxy-2-{[(4-ethoxyphenyl)sulfonyl]-4-methylanilino}propanoate (157 mg, 26.3%) was isolated as a light yellow oil, in 96.4% purity by HPLC (MaxPlot detection between 230 and 400 nm). Solvents were evaporated was washed with 1N HCl solution (7 mL) and with brine (7 mL) Organic phase was dried over MgSO4 evaporated The crude mixture was purified by flash chromatography