Verfahren zur Herstellung von Dithiophosphorsaeuretriestern

Di-thiophosphoric acid triesters of formula in which X is O or S, each R is an aliphatic or aromatic radicle, R1 is an aliphatic radicle and R2 is hydrogen or an aliphatic radicle are made by condensing one or more O,O-diesters of formula with an alcohol or mercaptan of formula HXR1 and an aldehyde p of formula R2CHO. As modifications the alcohol or mercaptan and aldehyde may be replaced by a vinyl ether or thioether of formula R2CH = CHXR3, where R3 is an aliphatic or aromatic radicle, when the products are then of formula or the alcohol or mercaptan used may be polyvalent of formula (HX)nR1, n being an integer greater than 1, and formaldehyde the aldehyde when the products are of formula the diester and formaldehyde being used in a molar excess of the polyhydric compound. Reaction is preferably effected at room or slightly elevated temperatures for a time usually about one to 24 hours. Many dithiophosphoric acid diesters are specified, including dialkyl, e.g. dimethyl, dioctadecyl and dicyclohexyl esters, diaryl, e.g. dichlor or dibromophenyl esters and mixed esters may also be used. Alcohols specified include methanol and octadecanol and may be straight or branched chain, primary, secondary or tertiary and the corresponding mercaptans or mixtures of alcohols and mercaptans may be used. Polyhydric compounds specified include ethylene and butylene glycols, glycerol and the corresponding thiols and thioalkanols such as betamercaptoethanol and gamma - mercaptopropanol. Vinyl ethers and thioethers may be vinylmethyl or vinylethyl ethers and ethers of halogenated phenols may also be used. Diluents may be present, e.g. benzene, toluene and solvent naphtha or one reagent may be in excess. The product is recovered by washing with water or dil. sodium carbonate solution and heating at 90-100 DEG C. under reduced pressure to remove volatiles. In examples, the following esters are made: (1) and (2) diethyl-S-ethoxymethyl-, (3) dimethyl-S-methoxyethyl-, (4) diethyl-S-n-propoxymethyl-, (5) di-n-propyl-S-isopropoxymethyl-, (6) diisopropyl-S-ethoxymethyl, (7) diisopropyl-S-isopropoxymethyl-, (8) di-n-butyl-S-ethoxymethyl-, (9) di-isobutyl-S-methoxymethyl-, (10) di-(methylisobutylcarbinyl) - S - methoxymethyl-, (11) diethyl - S - n-butoxymethyl-, and (12) di-(methylisobutylcarbinyl)-S-n-butoxymethyl-dithiophosphate, in (13) a dithiophosphoric acid diester is made from B24 alc