Hydrochloric Acid → tetraethyl N-benzyl-5-aminopentane-1,1-bisphosphonate

Temperature

0 °C

A solution of tetraethyl N-benzoyl-5-aminopentane-1,1-bisphosphonate (0.63 g, 1.36 mmol) in THF (3.4 mL) was cooled to 0° C., and borane methylsulfide (0.34 ml, 3.4 mmol) was added via syringe. The reaction was stirred at 0° C. for 20 minutes, then warmed to 65° C. for 2.5 hours. The reaction mixture was cooled to 0° C. and 6N HCl (4.0 ml) was added carefully. The solvent was removed in vacuo, and the residue was concentrated repeatedly from methanol (2×5 mL). The residue was dissolved in water (10 ml) and extracted with diethyl ether (3×5 ml). The aqueous layer was made basic to phenolphthalein with solid KOH and saturated with NaCl. The product was extracted into dichloromethane (5×20 ml), dried (Na2SO4) and concentrated to give the title compound (0.28 g).

1. temperaturewarmed to 65° C. for 2.5 hours
2. temperatureThe reaction mixture was cooled to 0° C.
3. customThe solvent was removed in vacuo
4. concentrationthe residue was concentrated repeatedly from methanol (2×5 mL)
5. dissolutionThe residue was dissolved in water (10 ml)
6. extractionextracted with diethyl ether (3×5 ml)
7. extractionThe product was extracted into dichloromethane (5×20 ml)
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated

ORD record

ord-861d1c5c6eb14e7f813a68ed25b21881

Source dataset

uspto-grants-1998_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05728650