Sodium amide → [[(6-Chloro-3-pyridinyl)amino]methylidene]-bisphosphonic acid tetraethylester

Participants

Reaction Steps

6-Chloro-3-aminopyridine was alkylated with diethyl iodomethylphosphonate, sodium amide as base, with known methods. The obtained 6-chloro-3-pyridinylamino-methylphosphonic acid diethylester (0.5 mol) and N-bromosuccinimid (0.5 mol) in anhydrous carbontetrachloride is irradiated 2 hours with a 200 W lamp. The solid is filtered off, washed with carbontetrachloride and the solution is concentrated in vacuo. The obtained 6-chloro-3-pyridinylamino(bromomethyl)-phosphonic acid diethylester (0.1 mol) is warmed in tetrahydrofuran with triethylphosphite (0.1 mol) in 50° C. for 4 hours. The reaction mixture is concentrated in vacuo. The product is purified chromatographically (eluent dichloromethane: methanol 9:1). Yield 5.1 g.

Provenance & Evidence