ethyl 4-diethoxyphosphorylbutanoate

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of triethyl 4-phosphonobutyrate (1.00 g, 3.96 mmol) in 1 mL of THF was added to potassium bis(trimethylsilyl)amide (0.5 M in THF, 8.70 ml, 4.36 mmol) at −78° C. After stirring for 1 h at −78° C., 1-iodododecane (1.2 mL, 4.75 mmol) was added dropwise. The reaction was removed from the bath, warmed to rt and stirred for 2 h. The reaction was diluted with ethyl acetate (50 ml), washed with 2 N HCl (50 mL), sat'd NaCl (50 mL), dried and concentrated. Flash chromatography using 3:1 v/v hexane/acetone afforded 610 mg of the title compound: ESI-MS 421.3 (M+H). The reaction was removed from the bath warmed to rt stirred for 2 h The reaction was diluted with ethyl acetate (50 ml) washed with 2 N HCl (50 mL), sat'd NaCl (50 mL) dried concentrated

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of triethyl 4-phosphonobutyrate (1.00 g, 3.96 mmol) in 1 mL of THF was added to potassium bis(trimethylsilyl)amide (0.5 M in THF, 8.70 ml, 4.36 mmol) at −78° C. After stirring for 1 h at −78° C., 1-iodododecane (1.2 mL, 4.75 mmol) was added dropwise. The reaction was removed from the bath, warmed to rt and stirred for 2 h. The reaction was diluted with ethyl acetate (50 ml), washed with 2 N HCl (50 mL), sat'd NaCl (50 mL), dried and concentrated. Flash chromatography using 3:1 v/v hexane/acetone afforded 610 mg of the title compound: ESI-MS 421.3 (M+H). The reaction was removed from the bath warmed to rt stirred for 2 h The reaction was diluted with ethyl acetate (50 ml) washed with 2 N HCl (50 mL), sat'd NaCl (50 mL) dried concentrated

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

Procedure: If 110 g (0.43 mol) of triethyl 4-phosphonobutyrate and 48.6 g (0.45 mol) of o-phenylenediamine are reacted with one another in 200 g of concentrated HCl and 200 g of H2O according to Example 1, 52.5 g (51.5% of theory) of 3-[benzimidazol-2-yl]-propanephosphonic acid are obtained as light grey crystals with a melting point of about 280° C. (decomposition). ##STR19##

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of triethyl 4-phosphonobutyrate (1.00 g, 3.96 mmol) in 1 mL of THF was added to potassium bis(trimethylsilyl)amide (0.5 M in THF, 8.70 ml, 4.36 mmol) at −78° C. After stirring for 1 h at −78° C., 1-iodododecane (1.2 mL, 4.75 mmol) was added dropwise. The reaction was removed from the bath, warmed to rt and stirred for 2 h. The reaction was diluted with ethyl acetate (50 ml), washed with 2 N HCl (50 mL), sat'd NaCl (50 mL), dried and concentrated. Flash chromatography using 3:1 v/v hexane/acetone afforded 610 mg of the title compound: ESI-MS 421.3 (M+H). The reaction was removed from the bath warmed to rt stirred for 2 h The reaction was diluted with ethyl acetate (50 ml) washed with 2 N HCl (50 mL), sat'd NaCl (50 mL) dried concentrated