Manufacture of aryl phosphate esters

Claim 1

AN IMPROVED PROCESS FOR PRODUCTING PHENOLIC PHOSPHATE ESTERS ,WHICH COMPRISES RECTING IN TWO STAGES, A PHENOLIC COMPOUND REACTANT SELECTED FROM THE GROUP CONSISTING OF PHENOL AND LOWER ALKYPHENOLS WITH PHOSPHORUS OXYCHLORIDE, IN A MOLAR RATIO OF AT LEAST 3:1,RESPECTIVELY, AND IN THE PRESENCE OF CATALYTIC AMOUNTS OF MAGNESIUM CHLORIDE,IN THE FIRST STAGE, HEATING THE REACTION MIXTURE AT A TEMPERATURE OF BETWEEN ABOUT 100*C. AND ABOUT 125*C. FOR BETWEEN ABOUT ONE HOUR AND ABOUT 3 HOURS, IN THE SECOND STAGE, INCREASING THE REACTION TEMPERATURE OF THE FIRST STAGE TO ABOUT 200* C. AT A RATE OF BETWEEN ABOUT 0.5*C. PER MINUTE AND ABOUT 5*C. PER MINUTE, THE TOTAL REACTION TIME IN BOTH STAGES BEING BETWEEN ABOUT 4 HOURS AND ABOUT 6 HOURS, AND OPERATING UNDER REDUCED PRESSURE DURING THE LATTER 0.5 HOUR TO 1.5 HOURS OF THE REACTION TIME, NEUTRALIZING THE REACTION MIXTURE WITH A SOLID, WEAKLY BASIC INORGANIC SALT, AND SEPARATING SAID PHENOLIC PHOSPHATE ESTER.