the hydrolytic condensation of the dihydrocarbylhalophosphate involves reaction of water with a compound of the formula ## str2 ## where r is hydrocarbyl ( independently alkyl , aryl , alkaryl , arylalkyl , etc .) and x is halogen . the foregoing hydrocarbyl moieties can either be unsubstituted or can be substituted with non - interfering substituents to the instant reaction ( e . g ., halogen ). this can be practiced at temperatures of from about 50 ° c . to about 170 ° c . and results in formation of a pyrophosphate compound of the formula ## str3 ## where r has the meaning given above . r can be substituted or unsubstituted phenyl , if desired . examples of substituted phenyl groups r in the foregoing formula include xylyl , 2 , 6 - dichlorophenyl , 4 - tert - butylphenyl , 2 , 3 , 4 , 5 , 6 - pentachlorophenyl , 4 -( 1 , 3 - dimethylbutyl ) phenyl , 3 - methylphenyl , 4 - chlorophenyl , 3 - nitrophenyl , 4 - nitrophenyl , and the like . the hydrolytic condensation of dialkylhalophosphates is known ( see j . amer . chem . soc . vol . 70 , 3882 - 3886 and vol . 71 , 2268 ). in order to achieve the insertion of the desired hydrocarbyl bridging group between the two phosphate moieties in the pyrophosphate , that compound is then reacted with a cyclic ether . the cyclic ether can be of the formula ## str4 ## where each of r 1 - r 4 are independently hydrogen or substituted or unsubstituted alkyl or aryl , r is substituted or unsubstituted alkylene , and n is an integer of from 0 to 1 . representative ethers which can be used include ethylene oxide , propylene oxide , epichlorohydrin , epibromohydrin , cyclohexene oxide , epoxidized soybean oil , oxetane , 3 , 3 - dimethyloxetane , 3 , 3 - bis ( chloromethyl ) oxetane , 3 , 3 - bis ( bromomethyl ) oxetane , the diglycidyl ether of bisphenol a , the brominated diglycidyl ether or bisphenol a , and the like . the reaction of the pyrophosphate with the cyclic ether can be conducted at temperatures of from about 30 ° c . to about 160 ° c . using molar ratios of pyrophosphate to ether ranging from about 1 : 1 to about 1 : 2 . advantageously , a catalytically effective amount ( e . g ., from about 0 . 1 % to about 2 %, by weight , based on the weight of the pyrophosphate ) of amine or lewis acid catalyst is used to accelerate the reaction . to 10 moles of diphenylchlorophosphate ( 2686 gm ) heated to 70 ° c . under nitrogen , was added 5 moles ( 90 gm ) of water over a period of five hours . the temperature was kept at 75 ° c . throughout the addition . at the end of the addition period , the reaction mixture was kept at 75 °- 80 ° c . for one hour , and the temperature was then raised and maintained at 120 ° c . for three hours . it was then raised to 140 ° c . and maintained at that temperature for an additional three hours . a reddish orange oil ( 2430 gm , 98 . 7 % yield ) was obtained and assayed at 96 % purity by 31 p nmr . ethylene glycol bis ( diphenyl phosphate ) was made by the following procedure . to the tetraphenyl pyrophosphate from example 1 ( 0 . 5 mole , 243 gm ) was added 2 ml of pyridine . this mixture was heated to 70 ° c . under nitrogen . ethylene oxide ( 43 gm , 0 . 98 mole ) was slowly fed into the resulting mixture at 70 ° c . over ten hours . at the end of this time , the excess ethylene oxide was removed by applying slight vacuum . the reaction mixture was washed at 60 ° c . with 200 ml of 2 % sulfuric acid , followed by 200 ml of 2 % sodium hydroxide and two aliquots of 200 ml of water . traces of water were removed at 100 ° c . under vacuum . the viscous yellow oil that remained ( 224 . 6 gm , 87 . 4 % yield ) was analyzed . on standing , the oil solidified ( mp = 38 °- 40 ° c .). the hydrogen and 31 p nmr analysis was consistent with the proposed structure . the material assayed at 97 . 2 % by high pressure liquid chromatography . this example illustrates the preparation of propylene glycol bis ( diphenyl phosphate ). to the tetraphenyl pyrophosphate from example 1 ( 0 . 5 mole , 243 gm ), that had been heated to 70 ° c . under nitrogen , was added a solution of 32 gm ( 0 . 55 mole ) of propylene oxide and 3 ml of pyridine over a period of three hours . the reaction mixture was kept at 70 ° c . for six hours . excess propylene oxide was distilled from the reaction mixture . after washing and drying , as described in example 2 , there was left 218 gm of a colorless oil ( 80 % yield ). the anticipated identity of the product was confirmed by 1 h and 31 p nmr and the material assayed at 96 . 7 % purity by 31p nmr . neopentyl glycol bis ( diphenyl phosphate ), as claimed in u . s . ser . no ., 374 , 716 , entitled &# 34 ; novel aromatic bisphosphates &# 34 ; was made by this example . to tetraphenyl pyrophosphate from example 1 ( 0 . 5 mole , 243 gm ), heated to 80 ° c . under nitrogen , was added a solution of 3 , 3 - dimethyl oxetane ( 0 . 5 mole , 43 . 1 gm ) and 2 ml of pyridine . the temperature was raised to 120 ° c . and was kept at constant temperature for ten hours . after washing and drying as described in example 2 , there was obtained 253 . 5 gm of a light yellow oil ( 89 % yield ). the identify of the product was confirmed by 1 h and 31 p nmr , and this material assayed at 92 % purity by 31 p nmr . dichloroneopentyl glycol bis ( diphenyl phosphate ), as also claimed in u . s . ser . no . 374 , 716 , was made in this example . it was made as described in example 4 from 0 . 32 mole , 154 . 2 gm of tetraphenyl pyrophosphate , 0 . 32 mole ( 50 gm ) of 3 , 3 - bis ( chloromethyl ) oxetane and 2 ml of pyridine . a viscous light brown oil ( 152 . 4 gm ) was obtained at 75 % yield . the identity of the product was confirmed by 1 h nmr . propylene glycol bis ( diphenylphosphate ) was made in this example . to 0 . 5 mole of tetraphenylpyrophosphate ( 243 grams ) was added 0 . 2 grams of magnesium chloride . the mixture was heated to 80 ° c . propylene oxide ( 50 ml ) was slowly added over six hours with the temperature being kept at 80 ° c . after the addition was completed , the reaction mixture was heated to 85 ° c . for an additional four hours . it was then washed at 50 ° c . with 200 ml of 2 % sulfuric acid , 200 ml of 2 % sodium hydroxide , and two 200 ml portions of water . after removal of traces of water at vacuum at 90 ° c ., there was left 218 grams ( 80 . 7 % yield ) of a colorless oil which , by 31 p nmr analysis , was shown to contain 84 % of the desired bisphosphate and 14 % of triphenylphosphate by - product . example 6 was repeated using stannous octoate as a catalyst ( at 0 . 3 % by weight of tetraphenylpyrophosphate ) and ethylene oxide in place of propylene oxide in order to produce ethylene glycol bis ( diphenylphosphate ). the results were comparable to those achieved in example 6 . the foregoing examples have been presented to illustrate certain embodiments of the instant invention and , for this reason , should not be construed in a limiting sense . the scope of protection that is sought is set forth in the claims which follow .