Patent GB-716978-A (GB)
Title: Improvements in or relating to dialkyl monoaryl esters of ortho-phosphoric acid and methods of preparing the same
IPC: C07F9/12
Filed: 1951-11-02
Abstract: The invention comprises as new compounds dialkyl monoaryl orthophosphate esters having the formula R1O.P(O)(OR2)(OR3), in which R1 is an alkyl group terminating in a methylene group and containing from 1 to 6 carbon atoms, R2 is an alkyl group terminating in a methylene group and containing not more than ten carbon atoms and differing from R1 by at least four carbon atoms and R3 is a phenyl or a cresyl group.  The esters may be prepared by reacting a primary alkanol containing 1 to 6 carbon atoms and phosphorus oxychloride to form a monoalkyl phosphoryl dichloride and then reacting the latter with a primary alkanol containing not more than ten carbon atoms and differing from the first alcohol by at least four carbon atoms to form a dialkyl phosphoryl monochloride which is then reacted with an alkali metal salt of a phenol or cresol in aqueous medium. Alternatively, the dialkyl phosphoryl monochloride may be prepared by reacting the primary alkanol containing from 1 to 10 carbon atoms with phosphorus oxychloride to form a monoalkyl phosphorus dichloride and then reacting the latter with the primary alkanol containing not more than six carbon atoms to form the dialkyl phosphoryl monochloride. In examples: (1) 2-ethylhexyl n-butyl phenyl phosphate is prepared by reacting 2-ethylhexanol with phosphorus oxychloride, reacting the product with n-butyl alcohol to form 2-ethylhexyl n-butyl phosphoryl monochloride and then adding the latter to a stirred sodium phenate solution prepared from phenol, water, and a 50 per cent aqueous sodium hydroxide solution; (2) to (8) n-octyl-n-butyl phenyl phosphate, 2-ethylhexyl n-butyl cresyl phosphate, 2-ethylhexyl isobutyl phenyl phosphate, 2-ethylhexyl methyl phenyl phosphate, decyl methyl phenyl phosphate, nonyl isoamyl phenyl phosphate and n-octyl n-butyl cresyl phosphate respectively are obtained by a similar procedure as in (1).  In the production of the monoalkyl phosphoryl dichloride the preferred reaction temperature is from 2 DEG  to 25 DEG  C. and after reaction is substantially complete the temperature may be increased to a maximum of 50 DEG  C. to facilitate the removal of the hydrogen chloride evolved.  In the preparation of the dialkyl phosphoryl monochloride and in the reaction between the alkali metal phenate and the dialkyl phosphoryl monochloride the reaction temperature is preferably from -10 DEG  to +50 DEG  C.  The ester products are stated to have utility as functional fluids (see Groups III and XXIX) and particularly as synthetic lubricants and force transmission fluids. They are also useful as film-forming addition agents for extreme pressure lubricants and as the liquid medium for filters for air-conditioning systems.ALSO:Dialkyl monoaryl orthophosphate esters having the formula R1O.P(O)(OR2)(OR3) in which R1 is an alkyl group terminating in a methylene group and containing from 1 to 6 carbon atoms, R2 is an alkyl group terminating in a methylene group and containing not more than ten carbon atoms and differing from R1 by at least four carbon atoms and R3 is a phenyl or a cresyl group (see Group IV (b)) are stated to have utility as functional fluids and particularly as synthetic lubricants and force transmission fluids (see Group XXIX).  They may be combined with paraffinic hydrocarbon oils and may also be used as film forming addition agents for extreme pressure lubricants.