Method for preparing O,O-dialkyl S-[2-(alkylthio)alkyl] phosphorodithioates
AssigneeBayer CropScience AG
InventorsVidyanatha A. Prasad, Robert D. Ingalls, Stephen C. Slahck, Christopher M. Tusa
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Abstract
The invention relates to a method of preparing O,O-dialkyl S-[2-(alkylthio)alkyl]phosphorodithioates by treating -O,O-dialkyl dithiophosphoric acids with a base in the substantial absence of organic solvent to obtain O,O-dialkyl dithiophosphoric acid salts that are in turn treated with thioalcohol derivatives to form the O,O-dialkyl S-[2-(alkylthio)alkyl]phosphorodithioates.
Claims22
A method of preparing an O,O-dialkyl S-[2-(alkylthio)alkyl]phosphorodithioate having the formula
- 7
- wherein
- each R1 is independently C1-C4 alkyl,
- R2 is C1-C4 alkylene, and
- R3 is C1-C4 alkyl,
- comprising
- (a) treating an O,O-dialkyl dithiophosphoric acid of the formula:
- 8
- wherein each R1 is independently C1-C4 alkyl,
- with a base in the substantial absence of organic solvent to obtain an O,O-dialkyl dithiophosphoric acid salt of the formula:
- 9
- wherein
- each R1 is independently C1-C4 alkyl, and
- X is a cation, and
- (b) reacting the O,O-dialkyl dithiophosphoric acid salt with a halothioalcohol having the formula:
- R3-S-R2-Y
- wherein
- R2 is C1-C4 alkylene,
- R3 is C1-C4 alkyl, and
- Y is a leaving group.
A method of preparing O,O-diethyl S-[2-(ethylthio)ethyl]phosphorodithioate comprising
- (a) treating O,O-diethyl dithiophosphoric acid with a base in the substantial absence of organic solvent to form an O,O-diethyl dithiophosphoric acid salt, and
- (b) reacting the O,O-diethyl dithiophosphoric acid salt with β-chloroethyl ethyl sulfide.
A method of preparing an O,O-dialkyl S-[2-(alkylthio)alkyl]phosphorodithioate having the formula
- 10
- wherein
- each R1 is independently CH3, C2H5, n-C3H7, or i-C3H7,
- R2 is CH2 or C2H4, and
- R3 is CH3 or C2H5,
- comprising
- (a) treating an O,O-dialkyl dithiophosphoric acid of the formula:
- 11
- wherein each R1 is independently CH3, C2H5, n-C3H7, or i-C3H7,
- with a base in the presence of water and in the substantial absence of organic solvent to form an organic portion and an aqueous portion containing O,O-dialkyl dithiophosphoric acid salt of the formula:
- 12
- wherein
- each R1 is independently CH3, C2H5, n-C3H7, or i-C3H7, and
- X is a cation, and
- (b) separating the aqueous portion containing the O,O-dialkyl dithiophosphoric acid salt, and
- (c) heating the aqueous portion containing the O,O-dialkyl dithiophosphoric acid salt with a halothioalcohol having the formula
- R3-S-R2-Y
- wherein
- R2 is CH2 or C2H4,
- R3 is CH3 or C2H5, and
- Y is a halogen.
A method of preparing an O,O-dialkyl dithiophosphoric acid salt comprising
- (a) treating an O,O-dialkyl dithiophosphoric acid with a base in the presence of water and in the substantial absence of organic solvent to form an organic portion and an aqueous portion containing O,O-dialkyl dithiophosphoric acid salt,
- (b) separating the aqueous portion containing O,O-dialkyl dithiophosphoric acid salt from the organic portion, and
- (c) isolating the O,O-dialkyl dithiophosphoric acid salt from the aqueous composition.
Dependencies are inferred from the claim text.