PREPARATION OF URETHANE AND UREA DERIVATIVES OF (NPCL2)3 - CRYSTAL-STRUCTURE OF A SPIROCYCLIC PHOSPHAZENE WITH A PHOSPHACYANURIC LOOP

Reactions of (NPCl2)3 with NaNCO in the presence of aliphatic alcohols have been investigated. Using an equimolar amount of NaNCO in refluxi ng acetonitrile, high yields of mono(urethane) derivatives N3P3Cl5(NHC O2R) were obtained. Disubstitution is mainly non-geminal. Reactions of (NPCl2)3 with AgNCO and methanol in acetonitrile follow a quite diffe rent pattern and lead to the formation of three products with basicall y geminal structures, e.g. gem-N3P3Cl4(OR)(NHCO2R), gem-N3P3Cl4(NH-CO2 R)2, and a spiro derivative (NPCl2)2NP[N(CO2R)C(O)NHC(CH3)N]. The crys tal structure of the last compound (R = CH3) has been determined. The difference between the reaction pathways observed for NaNCO and AgNCO is discussed in terms of S(N)2 and S(N)1 mechanisms, respectively. An improved synthesis of (NPCl2)2NP(NH2)(NCO) and its reactions with alco hols and amines are described.