Abstract The synthesis and crystal structure of diphenyl [(S)-(–)-1-phenylpropanamido]-phosphate, (C6H5O)2P(O)[NH-(S)-(–)CH(C2H5)(C6H5)], was previously reported. Here, the spectroscopic features (1H-NMR, 13C{1H}-NMR, 31P{1H}-NMR and IR) are investigated. In the 1H-NMR and 13C{1H}-NMR spectra, the diastereotopic C6H5O groups show two sets of signals. Typically, in the 13C{1H}-NMR spectrum, the doublets at 151.08/151.20 ppm and 120.52/120.55 ppm, with 2JCP = 6.5/6.6 Hz for the first pair and 3JCP = 4.9/4.7 Hz for the second pair are associated to the diastereotopic ipso-C atoms and diastereotopic ortho-C atoms. In the 1H-NMR spectrum, the signals related to diastereotopic phenyl groups overlap with those of phenyl group of chiral amine. The ipso-carbon atom of chiral amine fragment appears a doublet signal at 144.85 ppm (3JCP = 2.7 Hz). The phosphorus signal (31P{1H}-NMR) appears at –0.49 ppm. in this work NMR and spectroscopic main part are going to be consider and proved because of the chiral importance in drug delivery. Keywords: Amidophosphodiester; IR; NMR; Phosphorus-carbon coupling constant پرونده مقاله