Syntheses and spectroscopic investigations of 2-pyridyl(N/N)spirocyclotriphosphazenes

Abstract

The Cl substitution reaction of N3P3Cl6 (1) with N-(2-pyridyl)-methyl-N'-methylpropane-1,3-diamine (2) afforded the partly substituted 2-pyridyl(N/N)spirocyclotriphosphazene (3) (with a yield of 57%) in dry THF. When the Clreplacement reactions of 2 carried out with excess pyrrolidine, morpholine, and 1,4-dioxa-8-azaspiro[4,5]decane (DASD), the corresponding 2-pyridyl(N/N)spirotetrapyrrolidino(3a), tetramorpholino (3b) and tetra(1,4-dioxa-8-azaspiro[4,5]decano) (3c)cyclotriphosphazenes were prepared in moderate yields. The structures of fourcyclotriphosphazene derivatives were elucidated by the elemental analyses, Fouriertransform infrared (FTIR), heteronuclear mass spectrometry (ESI-MS), heteronuclearmultiple-bond correlation (HMBC), single quantum coherence (HSQC), 1H, 13C, and 31P NMRtechniques.