Synthesis
General procedure for the synthesis of trimethyl 3,3',3''-phosphono-tripropionate from methanol and tris(2-carboxyethyl)phosphine hydrochloride: tris(2-carboxyethyl)phosphine hydrochloride (TCEP) (7.0 g, 24.42 mmol) was co-evaporated with ethanol (EtOH) (2 × 100 mL) and subsequently dissolved in methanol (CH3OH) (200 mL) at 4 °C . Thionyl chloride (SOCl2) (9.0 mL, 122.29 mmol) was slowly added to this solution. The reaction mixture was stirred at room temperature overnight. Upon completion of the reaction, the mixture was concentrated and dried under vacuum to afford trimethyl 3,3',3''-phosphonyl tripropionate (7.0 g, 98% yield). The product was confirmed by electrospray ionization mass spectrometry (ESI MS) with an observed m/z of 293.2 (M+H)+.