S-hydrocarbyl thiophosphates prepn. - by reacting a thiophosphoric acid and a trihydrocarbyl phosphite

摘要

S-hydrocarbyl thiophosphates of formula (I): (RO)2-P(=X)SR' are prepd. by reacting approx. equimolar amts. of a thiphosphoric acid of formula (II) (RO)2-P(=X)SH and a trihydrocarbyl phosphite of formula (III) (R')3-P (where each R = H, 1-20C hydrocarbyl (pref. 1-14C alkyl phenyl) or substd. hydrocarbyl, provided at least one (pref. both) is hydrocarbyl; X = O, S (pref. S), each R' = 1-20C (pref. 1-10C) alkyl, aralkyl, substd. alkyl or substd. aralkyl). The pref. phosphite is triethyl- or tri-n-butylphosphite. Reaction is pref. at ambient temp. with addn. of phosphite over 0.5-2 hrs. (I) are esp. suitable for use as anti-oxidant and anti-wear additives in lubricating oils in concns. of 0.01-10 (0.1-5)% wt. The S alkyl thiophosphates may also be used as insecticides. The prepn. avoids the long reaction times of prior art methods (addn. of dithiophosphoric acids to olefins and reaction of metal salts of dithiophosphoric acids with alkyl halides).