Isomeric spiro and ansa macrocyclic derivatives of spiro-aminopropanoxy-cyclotriphosphazene

The spiro-aminopropanoxy group enables substituents to be distinguished above and below the plane of the cyclotriphosphazene ring. Spiro and ansa macrocyclic derivatives of cyclophosphazene have been investigated by stepwise reactions of the same two reagents added in different order. In the first route, hexachlorocyclotriphosphazene (1) was reacted with 3-amino-1-propanol (2) to give 2,2-(3′-amino-1′-propoxy)-4,4,6,6-tetrachloro-cyclotriphosphazene (4), which was then reacted with tetraethylene glycol (3) to give the mono-spiro (6), mono-ansa (7) and di-ansa (8) derivatives. In the second pathway, cyclophosphazene (1) was first reacted with tetraethylene glycol (3) to give 4,6-[oxy(tetraethyleneoxy)]-2,2,4,6,-tetrachlorocyclotriphosphazene (5), which was then reacted with 3-amino-1-propanol (2) to give the spiro-ansa compound (7) and its geometric isomer (9), in contrast to previous work when bis-β-naphthol was introduced as the second substituent. The mono-ansa compound (7) has the macrocycle cis to the NH group of the aminopropanoxy moiety, whereas the crystal structure of compound (9) confirms that it is the first mono-ansa derivative, when formed in a primary reaction, in which the macrocycle is trans to the NH group of the spiro-aminopropanoxy residue.