ethyl 2-[2-[2-(2-azidoethoxy)ethoxy]ethoxy]acetate

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

Procedure: To a solution of {2-[2-(2-Azido-ethoxy)-ethoxy]-ethoxy}-acetic acid ethyl ester (0.30 g, 1.15 mmol, 1 eq) in ethanol (7 mL) was added 1M HCl (2.30 mL, 2.30 mmol, 2 eq) and 30.0 mg of Pd/C (10%). The flask was then evacuated and filled with H2. The mixture was stirred under H2 atmosphere at room temperature until the starting material disappeared on the TLC plate and in mass spectra. The solution was filtered through celite and concentrated in vacuo to give a pale yellow syrup. The obtained 2-[2-(2-ethoxycarbonylmethoxy-ethoxy)-ethoxy]-ethyl-ammonium chloride can be stored at −18° C. for several months. Work-up to get the free amine should only be performed immediately before the next step. To obtain the free amine 350 mg (1.29 mmol) of the respective hydrochloride were dissolved in chloroform. The organic layer was washed with sat. aq K2CO3 and H2O, and the solvent was evaporated in vacuo at room temperature to give a colorless oil. Yield: 210 mg (0.89 mmol, 69%). The flask was then evacuated filled with H2 The solution was filtered through celite and concentrated in vacuo to give a pale yellow syrup

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

Procedure: To a solution of {2-[2-(2-Azido-ethoxy)-ethoxy]-ethoxy}-acetic acid ethyl ester (0.30 g, 1.15 mmol, 1 eq) in ethanol (7 mL) was added 1M HCl (2.30 mL, 2.30 mmol, 2 eq) and 30.0 mg of Pd/C (10%). The flask was then evacuated and filled with H2. The mixture was stirred under H2 atmosphere at room temperature until the starting material disappeared on the TLC plate and in mass spectra. The solution was filtered through celite and concentrated in vacuo to give a pale yellow syrup. The obtained 2-[2-(2-ethoxycarbonylmethoxy-ethoxy)-ethoxy]-ethyl-ammonium chloride can be stored at −18° C. for several months. Work-up to get the free amine should only be performed immediately before the next step. To obtain the free amine 350 mg (1.29 mmol) of the respective hydrochloride were dissolved in chloroform. The organic layer was washed with sat. aq K2CO3 and H2O, and the solvent was evaporated in vacuo at room temperature to give a colorless oil. Yield: 210 mg (0.89 mmol, 69%). The flask was then evacuated filled with H2 The solution was filtered through celite and concentrated in vacuo to give a pale yellow syrup

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

Procedure: To a solution of {2-[2-(2-Azido-ethoxy)-ethoxy]-ethoxy}-acetic acid ethyl ester (0.30 g, 1.15 mmol, 1 eq) in ethanol (7 mL) was added 1M HCl (2.30 mL, 2.30 mmol, 2 eq) and 30.0 mg of Pd/C (10%). The flask was then evacuated and filled with H2. The mixture was stirred under H2 atmosphere at room temperature until the starting material disappeared on the TLC plate and in mass spectra. The solution was filtered through celite and concentrated in vacuo to give a pale yellow syrup. The obtained 2-[2-(2-ethoxycarbonylmethoxy-ethoxy)-ethoxy]-ethyl-ammonium chloride can be stored at −18° C. for several months. Work-up to get the free amine should only be performed immediately before the next step. To obtain the free amine 350 mg (1.29 mmol) of the respective hydrochloride were dissolved in chloroform. The organic layer was washed with sat. aq K2CO3 and H2O, and the solvent was evaporated in vacuo at room temperature to give a colorless oil. Yield: 210 mg (0.89 mmol, 69%). The flask was then evacuated filled with H2 The solution was filtered through celite and concentrated in vacuo to give a pale yellow syrup