3 2 c 8 f 17 ch 2 ch oh ch 2 o 2 pooch ch 3 2 the base which is used to hydrolyze the alkyl ester of di fluoroalkyl containing group substituted alkyl phosphate of the formula ii is preferably an alkali hydroxide an ammonium hydroxide or an amine examples of the alkali hydroxide are potassium hydroxide and sodium hydroxide examples of the amine are trimethylamine triethylamine tripropylamine tributylamine triethanolamine diethylamine dipropylamine diethanolamine ethylamine propylamine and ethanolamine the hydrolysis can be carried out by adding ammonium hydroxide or an amine water mixture or an alkali hydroxide alcohol water mixture to the alkyl ester of di fluoroalkyl containing group substituted alkyl phosphate the alcohol which is used in hydrolysis includes a secondary or tertiary c 3 c 6 alcohol such as isopropyl alcohol tert butyl alcohol sec butyl alcohol tert amyl alcohol isoamyl alcohol and sec amyl alcohol the base is used in an amount of at least one equivalent preferably 1 to 10 equivalents per mole of the alkyl di fluoroalkyl containing group substituted alkyl phosphate the pressure during hydrolysis is not critical usually the hydrolysis is carried out under an atmospheric pressure at a temperature of 80 u00b0 to 100 u00b0 c for 2 to 6 hours the alkyl ester of di fluoroalkyl containing group substituted alkyl phosphate of the formula ii can be prepared by reacting a fluoroalkyl containing group substituted alcohol of the formula wherein r f a 1 k and m are the same as defined above with a phosphoryl monoalkoxide dihalide of the formula wherein each x is independently halogen atom for example chlorine or bromine and r is the same as defined above c 8 f 17 so 2 n c 2 h 5 ch 2 ch 2 oh c.