N-(1,3,2-Dioxaphosphorinan-2-ylmethyl) thiophosphoramidates were synthesized and determined by NMR spectra and positive ion electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). The fragmentation pathways were investigated. The results show that these characteristic ions in ESI mass spectra are useful in the structural determination of N-(1, 3, 2-dioxaphosphorinan-2-ylmethyl)- thiophosphoramidates.

An improved method for the synthesis of Diphenyl α-(diethoxythiophosphorylamino) methylphosphonates under mild conditions is described. It consists of the reaction of diethyl thiophosphoramidate (1) with triphenyl phosphite (3) and a substituted benzylaldehyde or ketone (2) by a one-pot procedure with the aid of acetyl chloride.

The synthesis of a novel quinone fused phosphorus heterocycle, 2-chloro-3, 3-disub- stituents-3, 4-dihydro-2H-naphtho[2, 3-e][1, 4, 2]-oxazaphosphinane-5, 10-dione 2-oxide (3a–g), was described for the first time. These compounds, which have a readily leaving group Cl, can serve as intermediates of many quinone fused phosphorus heterocycles. The structures of 3a–g were characterized by using common spectroscopic methods. According to the X-ray structure of 3a, these compounds may be used as DNΑ-intercalators.

A study on the synthesis of the novel cyclic α-aminophosphonates and 2-alkoxy-2- oxo-1, 4, 2-oxazaphosphinanes 4a–r has been carried out. The title compounds were obtained in good yields by one-pot procedure using o-aminophenol, alkyl dichlorophosphinite, and ketones or benzaldehyde. One of their geometric stereoisomers was isolated and characterized. Configurations of 4k and one isomer of 4r have been established by X-ray diffraction analysis. The synthetic methods provide an easy access to the organophosphorus heterocycles with the ring system mentioned above. The abnormal chemical shifts of alkyl-substitute protons in 1H NMR spectra were given reasonable explanation.

A convenient and rapid method was developed for the synthesis of various N-phosphoramino α-aminoalkylphosphonates through Mannich type reactions under catalyst- and solvent-free conditions with excellent yields.