New symmetric diisopropylphosphoryl-S-alkanedi yldiisothioureas. Investigations on their synthesis

Symmetric dialkylphosphoryl-S-allcanediyldiisothioureas (RO)(2)P(O)NHC(=NH) S(CH2)(n) SC(=NH)NHP(O)(OR)(2) (I, R = isopropyl; n = 2-5) have potential c oordination sites involving O, P, N and S as donors atoms. For their synthe sis, common two-phase reactions between the corresponding diisothiourea der ivatives and diisopropyl phosphonate were unsuccessful. Herein we describe a new synthesis for such compounds using diisopropyl chlorophosphonate. Two new bis-phosphorylated alkanediyldiisothioureas with increasing carbon cha in (I; n = 3, n = 5) were prepared by this method.