WHEREIN X IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF NITRO, ACETYL AND METHYLSULFONYL, AND ITS THERAPEUTICALLY-COMPATIBLE SALTS, PROCESS OF PREPARATION OF THE PHOSPHATE ESTER AND METHODS OF THERAPY UTILIZING THE PHOSPHATE ESTER. THE SAID PHOSPHATE ESTERS HAVE AN IMPORTANT ANTIBIOTIC AND BACTERICIDAL ACTION COUPLED WITH EXCELLENT SOLUBILITY IN WATER. A PHOSPHATE ESTER SELECTED FROM THE GROUP CONSISTING OF THE 0-3-MONOPHSOPHASE OF D-THREO-1-PARA-X-PHENYL-2-DI CHLOROACETAMIDO-PROPANE-1,3-DIOL OF THE FORMULA