O-[2-(2-azidoethoxy)ethyl]hydroxylamine

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

Procedure: To a solution of O-(2-(2-azidoethoxy)ethyl)hydroxylamine (10 mg, 0.068 mmol), biotin (225 mg, 0.103 mmol) and DIPEA (29 mg, 0.206 mmol) in 0.8 mL of DMF was added PyBOP (54 mg, 0.103 mmol). The reaction was allowed to stir at room temperature for 2 h. Solvent was then removed in vacuo, and the crude product was purified by silica gel column chromatography (ethyl acetate: methanol 4:1) to afford azido-biotin (22 mg, 0.059 mmol, 88%) as a pale yellow solid. 1H NMR (CD3OD, 500 MHz) δ (ppm): 1.35 (m, 1H), 1.43 (m, 2H), 1.68 (stack, 4H), 2.11 (t, J=7.3 Hz, 2H), 2.70 (d, J=12.8 Hz, 1H), 2.92 (dd, J=5.0, 12.8 Hz, 1H), 3.20 (m, 1H), 3.43 (m, 2H), 3.67 (m, 2H), 3.72 (m, 2H), 3.98 (m, 2H), 4.30 (m, 1H), 4.48 (m, 1H). Solvent was then removed in vacuo the crude product was purified by silica gel column chromatography (ethyl acetate: methanol 4:1)

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

Procedure: To a solution of O-(2-(2-azidoethoxy)ethyl)hydroxylamine (10 mg, 0.068 mmol), biotin (225 mg, 0.103 mmol) and DIPEA (29 mg, 0.206 mmol) in 0.8 mL of DMF was added PyBOP (54 mg, 0.103 mmol). The reaction was allowed to stir at room temperature for 2 h. Solvent was then removed in vacuo, and the crude product was purified by silica gel column chromatography (ethyl acetate: methanol 4:1) to afford azido-biotin (22 mg, 0.059 mmol, 88%) as a pale yellow solid. 1H NMR (CD3OD, 500 MHz) δ (ppm): 1.35 (m, 1H), 1.43 (m, 2H), 1.68 (stack, 4H), 2.11 (t, J=7.3 Hz, 2H), 2.70 (d, J=12.8 Hz, 1H), 2.92 (dd, J=5.0, 12.8 Hz, 1H), 3.20 (m, 1H), 3.43 (m, 2H), 3.67 (m, 2H), 3.72 (m, 2H), 3.98 (m, 2H), 4.30 (m, 1H), 4.48 (m, 1H). Solvent was then removed in vacuo the crude product was purified by silica gel column chromatography (ethyl acetate: methanol 4:1)

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

Procedure: To a solution of 2-(2-(2-azidoethoxy)ethoxy)isoindoline-1,3-dione (43 mg, 0.17 mmol) in 0.8 mL of methanol was added hydrazine (5.5 mg, 0.17 mmol), and the resulting mixture was allowed to stir at room temperature for 2 h. Solvent was removed under reduced pressure, the crude product was purified by silica gel column chromatography (hexanes: ethyl acetate 1:2) to afford O-(2-(2-azidoethoxy)ethyl)hydroxylamine (15 mg, 0.10 mmol, 60%) as colorless oil. 1H NMR (CDCl3, 500 MHz) δ (ppm): 3.38 (t, J=4.8 Hz, 2H), 3.65 (stack, 4H), 3.82 (t, J=4.2 Hz, 2H), 5.49 (s, br, 2H). Solvent was removed under reduced pressure the crude product was purified by silica gel column chromatography (hexanes: ethyl acetate 1:2)

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

Procedure: To a solution of O-(2-(2-azidoethoxy)ethyl)hydroxylamine (10 mg, 0.068 mmol), biotin (225 mg, 0.103 mmol) and DIPEA (29 mg, 0.206 mmol) in 0.8 mL of DMF was added PyBOP (54 mg, 0.103 mmol). The reaction was allowed to stir at room temperature for 2 h. Solvent was then removed in vacuo, and the crude product was purified by silica gel column chromatography (ethyl acetate: methanol 4:1) to afford azido-biotin (22 mg, 0.059 mmol, 88%) as a pale yellow solid. 1H NMR (CD3OD, 500 MHz) δ (ppm): 1.35 (m, 1H), 1.43 (m, 2H), 1.68 (stack, 4H), 2.11 (t, J=7.3 Hz, 2H), 2.70 (d, J=12.8 Hz, 1H), 2.92 (dd, J=5.0, 12.8 Hz, 1H), 3.20 (m, 1H), 3.43 (m, 2H), 3.67 (m, 2H), 3.72 (m, 2H), 3.98 (m, 2H), 4.30 (m, 1H), 4.48 (m, 1H). Solvent was then removed in vacuo the crude product was purified by silica gel column chromatography (ethyl acetate: methanol 4:1)

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

Procedure: To a solution of 2-(2-(2-azidoethoxy)ethoxy)isoindoline-1,3-dione (43 mg, 0.17 mmol) in 0.8 mL of methanol was added hydrazine (5.5 mg, 0.17 mmol), and the resulting mixture was allowed to stir at room temperature for 2 h. Solvent was removed under reduced pressure, the crude product was purified by silica gel column chromatography (hexanes: ethyl acetate 1:2) to afford O-(2-(2-azidoethoxy)ethyl)hydroxylamine (15 mg, 0.10 mmol, 60%) as colorless oil. 1H NMR (CDCl3, 500 MHz) δ (ppm): 3.38 (t, J=4.8 Hz, 2H), 3.65 (stack, 4H), 3.82 (t, J=4.2 Hz, 2H), 5.49 (s, br, 2H). Solvent was removed under reduced pressure the crude product was purified by silica gel column chromatography (hexanes: ethyl acetate 1:2)