Neutral esters of dithiophosphoric acid

摘要

The invention comprises esters of the formula where R is an alkyl radical of 1 to 3 carbon atoms and x and y are 1 or 2. They are prepared by reacting the appropriate O,O-dialkyl dithiophosphoric acid either as an alkali metal salt or in the presence of an acid-binding agent, with a compound of the formula at temperatures of from room temperature to 80 DEG C., preferably in the presence of a solvent, e.g. water, benzene, acetone, methyl ethyl ketone and alcohols. In the examples, the following esters are prepared: (1) and (2) O,O-diethyl - S - methyl - mercaptoethyl -, (3) and (4) O,O-diethyl-S-ethylmercaptoethyl-, (5) O,O-diethyl - S - methylmercaptomethyl -, (6) and (7) O,O - diethyl - S - ethylmercaptomethyl -, (8) O,O - diethyl - S - ethylmercaptomethyl -, (9) O,O - di - n - propyl - S - ethylmercaptomethyl-, (10) O,O-di-isopropyl-S-ethylmercaptomethyl-, (11) O,O-dimethyl-S-ethylmercaptomethyl-, and (12) O,O-dimethyl-S-ethylmercaptoethyl - dithiophosphate. Specification 676,776 is referred to.ALSO:The invention comprises esters of dithiophosphoric acid which have contact-insecticidal and/or miticidal properties and have a high systemic effect on living plants and which have the general formula where R is an alkyl radical of 1 to 3 carbon atoms and x and y are 1 or 2. They may be applied as aqueous solutions or as powders containing a carrier. In the examples: (13) a 0,001 per cent aqueous solution of O, O-diethyl-S-ethylmercapto-methyl dithiophosphate containing a wetting agent is sprayed on green apple aphids, and in (16), in slightly varying concentration, is sprayed against Red Spider on bean plants: (14) the same compound, 2 gms., in admixture with talc, 98 gms., is used against Colorado beetles and their larvae: (15) a powder consisting of equal amounts of the compound of Example 13 and charcoal is applied to cotton seed. The compounds also have a toxic effect on mice. Specification 676,776 is referred to.