Process for the preparation of the 2-diethoxyphosphinylimino-1,3-dithietane
AssigneeAmerican Cyanamid Company
InventorsMurray Garber, David William Reger
Life of this patent
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Abstract
There is provided a fully integrated process for preparing a 2-dialkoxyphosphinylimino-1,3-dithietane in good overall yields with considerable savings in materials, time and labor involving a plurality of steps comprising the overall reaction of a dialkoxyphosphoryl chloride and an alkali metal or ammonium thiocyanate to obtain a dialkoxyphosphinyl isothiocyanate, reacting the latter with 1.1 to 1.2 molar equivalents of an alkali mercaptan in the presence of a water:acetone mixture (1:9 to 1:3), and finally reacting resultant dialkoxyphosphinyldithiocarbamate with methylene bromide or methylene iodide to obtain a 2-dialkoxyphosphylimino-1,3-dithietane.
Claims5
A fully integrated process for the preparation of a compound of formula:
- ##STR7## wherein R is C.sub.1 -C.sub.4 alkyl;
- consisting essentially in the steps of:
- reacting one molar equivalent of a compound of the formula:
- ##STR8## wherein R is as above defined, with a 1.0 to 1.2 molar equivalent of a thiocyanate selected from the group consisting of sodium-, potassium- and ammonium thiocyanate at a temperature range of 5.degree. C to 30.degree. C for a period of time so as to obtain a compound of formula:
- ##STR9## wherein R is as above defined;
- reacting the thus-formed compound without isolation from the above-said reaction mixture and in the presence of same with a 1.1 to 1.2 molar equivalent of sodium or potassium hydrosulfide in a water:acetone solvent system wherein the ratio of water:acetone is established in the range of 1:3 to 1:9 at a temperature range of 5.degree. C to 30.degree. C for a period of time so as to obtain a compound of the formula:
- ##STR10## wherein R is as above defined and M is an alkali metal, and reacting (a) the thus-formed compound in said water:acetone solvent system and in the presence of the reaction media with (b) a one to 2 molar equivalent of a methylene halide selected from the group consisting of methylene bromide and methylene iodide in the presence of a 1 to 2 molar equivalent of an alkali metal bicarbonate at a temperature of 25.degree. C to 35.degree. C for a period of time sufficient to essentially complete the reaction.
The fully integrated process for the preparation of a compound of formula:
- ##STR11## wherein R is C.sub.1 -C.sub.4 alkyl;
- consisting essentially in reacting one molar equivalent of a compound of formula:
- ##STR12## wherein R is as above defined, with a 1.0 to 1.2 molar equivalent of a thiocyanate selected from the group consisting of sodium-, potassium- and ammonium thiocyanate in the presence of one molar equivalent of a methylene halide selected from the group consisting of methylene bromide and methylene iodide at a temperature range of 5.degree. C to 30.degree. C for a period of time sufficient to essentially complete the reaction and obtain a compound of formula:
- ##STR13## wherein R is as above defined;
- reacting the thus formed compound without isolation from the above-said reaction mixture, in the presence of said reaction medium and the methylene halide added, with a 1.1 to 1.2 molar equivalent of sodium or potassium hydrosulfide in a water:acetone solvent system wherein the ratio of water:acetone is established and maintained in the range of 1:3 to 1:9 at a temperature range of 5.degree. C to 30.degree. C for a period of time sufficient to essentially complete the reaction and obtain a compound of the formula:
- ##STR14## wherein R is as above defined and M is an alkali metal, and reacting the compound thus formed without isolation in said water:acetone solvent system, and in the presence of the reaction media, with the above-defined 1 to 2 molar equivalent of methylene halide present in the reaction mixture from the start of said fully integrated process, in the presence of a 1 to 2 molar equivalent of sodium bicarbonate at a temperature range of 25.degree. C to 35.degree. C for a period of time sufficient to essentially complete the reaction.
Dependencies are inferred from the claim text.