AN IMPROVED SYNTHETIC METHOD AND THE FIRST CRYSTAL-STRUCTURES FOR (DIHALOMETHYLENE)BISPHOSPHONATE PARTIAL ESTERS

A new general and selective strategy for the synthesis of (dihalomethy lene)bisphosphonic acid (XYMBP) partial alkyl esters (PE) with high se lectivity and purity has been developed. Preparation is started from s elected XYMBP tetraesters using tertiary or secondary amines as dealky lating reagents leading to trialkyl or P,P'-dialkyl XYMBP PEs, respect ively. The solid state structures are given for three of the compounds : Cl2C[P(O)(OPri)(O-Na+)][P(O)(O-Na+)(2)] and Cl2C[P(O)(OPri)(O(-)X(+) )](2), Where X=Na+ or H2N+(CH2CH2)(2)O.