2-[(2-methylpropan-2-yl)oxycarbonyl-(2-methylpropyl)amino]acetic acid

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

Procedure: Nα-(tert-Butyloxycarbonyl)-Nα-(2-methylpropyl) glycine (360 mg, 1.56 mmol) was dissolved in CH2Cl2/DMF (9:1, 20 ml). The solution was cooled to 0° C., L-prolinamide hydrochloride (282 mg, 1.87 mmol), 1-hydroxybenzotriazole hydrate (295 mg, 2.18 mmol) and water soluble carbodiimide (358 mg, 1.87 mmol) were added and after 15 min the pH adjusted to pH9 with triethylamine. After 18 h at 0° C. to room temperature the solvent was removed in vacuo and the residue was taken up in ethyl acetate (100 ml). This solution was washed with 0.3M KHSO4, sat. NaHCO3, water and brine, dried (Na2SO4) and evaporated in vacuo. The residue was purified by flash chromatography (eluant: 4% methanol, 94% chloroform, 2% triethylamine) to give a colourless oil identified as the title compound (330 mg, 1.01 mmol, 65%). After 18 h at 0° C. to room temperature the solvent was removed in vacuo This solution was washed with 0.3M KHSO4, sat. NaHCO3, water and brine dried (Na2SO4) evaporated in vacuo The residue was purified by flash chromatography (eluant: 4% methanol, 94% chloroform, 2% triethylamine) to give a colourless oil

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

Procedure: Nα-(tert-Butyloxycarbonyl)-Nα-(2-methylpropyl) glycine methyl ester (960 mg, 3.91 mmol) was dissolved in THF/H2O (9:1, 25 ml). Lithium hydroxide monohydrate (492 mg, 11.7 mmol) was added. After 18 h at room temperature the reaction mixture was diluted with ethyl acetate (100 ml). This solution was washed with 1M HCl, water and brine, dried (Na2SO4) and evaporated in vacuo to give a colourless oil identified as the title compound (360 mg, 1.56 mmol, 40%). This solution was washed with 1M HCl, water and brine dried (Na2SO4) evaporated in vacuo to give a colourless oil