Preparation of N-hydrocarbylthiophosphoric triamides

• US 5,770,771 A
• Filed: 01/21/1997
• Issued: 06/23/1998
• Est. Priority Date: 01/21/1997
• Status: Expired due to Term

• Current Assignee: Albemarle Corporation
• Original Assignee: Albemarle Corporation
• Inventors: Cheng, Chi Hung, Kolich, Charles H., Sulzer, Gerald M., Klobucar, W. Dirk
• Primary Examiner(s): O SULLIVAN, PETER G
• Application Number:
  US08/786,396
• Time in Patent Office: 518 Days
• Field of Search: 564/14
• US Class Current: 564/14
• CPC Class Codes: C01C 1/164 Ammonium chloride
• CPC Class Codes: C07F 9/025 Purification; Separation; Stabilisation; Desodorisation of organo-phosphorus compounds of natural phosphatides C07F9/103; phosphines C07F9/5095
• CPC Class Codes: C07F 9/224 Phosphorus triamides
• CPC Class Codes: C07F 9/26 containing P-halide groups

Abstract

Continuously fed to and mixed in a first reactor are (i) a preformed mixture of primary hydrocarbyl monoamine, tertiary amine and liquid inert organic solvent, and (ii) thiophosphoryl chloride while removing heat of reaction to maintain the reaction temperature in the range of about -20° C. to about +50° C. A reaction mixture containing N-hydrocarbylaminothiophosphoryl dichloride is formed. Ammonia and an effluent stream from the first reactor are continuously fed to and mixed in a second reactor in proportions of at least about 16 moles, of ammonia per mole of N-hydrocarbylaminothiophosphoryl dichloride that produce a reaction mixture containing N-hydrocarbylthiophosphoric triamide, and that keep in solution ammonium chloride co-product formed in the reaction. Heat of reaction is removed so that the temperature is high enough to keep ammonium chloride-ammonia complex from forming a solid phase in this reaction mixture, but low enough to avoid significant reduction in yield of N-hydrocarbylthiophosphoric triamide being formed. Effluent is withdrawn from the second reactor so as to maintain a substantially constant volume of reaction mixture in the second reactor. The process eliminates a difficult filtration of the co-product ammonium chloride formed in the second reaction. Also, it possible to accomplish this in a continuous process, with improved efficiency in large scale production of the N-hydrocarbylthiophosphoric triamides. Moreover, the ammonium chloride can be readily converted in the process to an industrially useful liquid co-product mixture.

Claims

1. A process for the preparation of N-hydrocarbylthiophosphoric triamide, which process comprises:

a) continuously feeding to and mixing in a first reaction chamber (i) a preformed mixture of primary hydrocarbyl monoamine, tertiary amine and at least one liquid inert organic solvent, and (ii) thiophosphoryl chloride and removing heat of reaction at a rate sufficient to maintain the temperature of the reaction mixture in the range of about -20°

C. to about +50°

C., to produce a reaction mixture containing N-hydrocarbylaminothiophosphoryl dichloride;

b) continuously feeding and mixing in a second reaction chamber (i) an effluent stream of reaction mixture formed in the first reaction chamber, and (ii) ammonia in proportions (1) that are at least about 16 moles of ammonia per mole of N-hydrocarbylaminothiophosphoryl dichloride, (2) that produce a reaction mixture containing N-hydrocarbylthiophosphoric triamide, and (3) that keep in solution substantially all of the ammonium chloride co-product formed in the reaction, and removing heat of reaction from the mixture formed in b) at a rate of removal such that the temperature of the reaction mixture remains high enough to keep ammonium chloride-ammonia complex from forming an appreciable amount of solid phase in said reaction mixture, but low enough to avoid significant reduction in yield of N-hydrocarbylthiophosphoric triamide; and

c) withdrawing effluent from the second reaction chamber at a rate sufficient to maintain a substantially constant volume of reaction mixture in the second reaction chamber.

2. A process according to claim 1 wherein the effluent from the first reaction chamber is withdrawn therefrom and fed to the second reaction chamber at a rate that maintains a substantially constant volume of reaction mixture in the first reaction chamber.

3. A process according to claim 1 wherein the effluent from c) is caused/allowed to separate into an inorganic phase comprising predominately ammonia, ammonium chloride and co-product thiophosphoric triamide, and an organic phase comprising predominately N-hydrocarbylthiophosphoric triamide, tertiary amine, solvent and dissolved ammonia, and the resultant phases are separated from each other.

4. A process according to claim 3 wherein ammonia along with a portion of the solvent are separated from said organic phase, and are compressed and cooled to form (i) a recycle mixture of liquid ammonia and solvent, and thereby also provide (ii) a concentrated residual product mixture comprising predominately N-hydrocarbylthiophosphoric triamide, and residual solvent and tertiary amine;

and wherein the recycle mixture is recycled for use as a portion of the ammonia feed to the second reaction chamber.

5. A process according to claim 4 wherein tertiary amine and solvent are also separated from the ammonia-free organic phase and recycled for use as a portion of the feed for making the preformed mixture of a), and wherein the residual portion of the organic phase comprises N-hydrocarbylthiophosphoric triamide, and only small residual amounts of solvent and dissolved ammonia.

6. A process according to claim 5 wherein N-hydrocarbylthiophosphoric triamide and the small residual amounts of solvent and tertiary amine are separated from each other to yield a purified N-hydrocarbylthiophosphoric triamide product.

7. A process according to claim 6 wherein separated residual solvent is recycled for use as a portion of the feed for making the preformed mixture of a).

8. A process according to claim 1 wherein the heat of reaction from the mixture of a) is removed by continuously circulating a portion of the mixture of a) into a heat exchanger where heat is removed by a cooling medium and thence back to the first reaction chamber.

9. A process according to claim 1 wherein the heat of reaction from the mixture of a) is removed by controlling the pressure such that the mixture of a) boils and the vapors from said boiling mixture are condensed in a dephlegmator heat exchanger and refluxed back to the first reaction chamber.

10. A process according to claim 1 wherein the proportions of primary hydrocarbyl monoamine and tertiary amine in said preformed mixture are in a molar ratio range of 1:

1 to 1;

1.5 respectively, and the proportions of said preformed mixture and the thiophosphoryl chloride fed to the first reaction chamber are such that per mole of thiophosphoryl chloride there are in the range of about 0.95 to about 1.1 moles of primary hydrocarbyl monoamine and in the range of about 0.95 to about 1.5 moles of tertiary amine.

11. A process according to claim 10 wherein the reaction mixture in the first reaction chamber is continuously stirred/agitated by a mechanical stirrer/agitator, and wherein the preformed mixture and the thiophosphoryl chloride are both fed into such reaction mixture below the surface thereof and in close proximity to the stirrer/agitator to ensure rapid mixing of these feeds.

12. A process according to claim 1 wherein the heat of reaction from the mixture of b) is removed by continuously circulating a portion of the mixture of b) through a heat exchanger and thence back to the second reaction chamber.

13. A process according to claim 1 wherein said first and said second reaction chambers are heat exchangers that provide a residence time in the range of 1 to about 10 minutes and that provide sufficient heat exchange surface in contact with the reaction mixture to enable removal of the heat of reaction generated within said residence time.

14. A process for the preparation of N-alkylthiophosphoric triamide, which process comprises:

a) continuously feeding to and mixing in a first reaction chamber (i) a preformed mixture of primary alkyl monoamine, tertiary amine and at least one liquid inert organic solvent, and (ii) thiophosphoryl chloride and removing heat of reaction at a rate sufficient to maintain the temperature of the reaction mixture in the range of about -20°

to about +50°

C., to produce a reaction mixture containing N-alkylaminothiophosphoryl dichloride;

b) continuously feeding and mixing in a second reaction chamber (i) an effluent stream of reaction mixture formed in the first reaction chamber which effluent is withdrawn at a rate to maintain a substantially constant volume of reaction mixture in the first reaction chamber, and (ii) ammonia in proportions (1) that are at least about 16 moles of ammonia per mole of N-alkylaminothiophosphoryl dichloride, (2) that produce a reaction mixture containing N-alkylthiophosphoric triamide, and (3) that keep in solution substantially all of the ammonium chloride co-product formed in the reaction, and removing heat of reaction from the mixture formed in b) at a rate of removal such that the temperature of the reaction mixture remains high enough to keep ammonium chloride-ammonia complex from forming an appreciable amount of solid phase in said reaction mixture, but low enough to avoid significant reduction in yield of N-alkylthiophosphoric triamide;

c) withdrawing effluent from the second reaction chamber at a rate sufficient to maintain a substantially constant volume of reaction mixture in the second reaction chamber; and

d) enabling/causing the effluent from c) to separate into an inorganic phase comprising predominately ammonia, ammonium chloride and co-product thiophosphoric triamide, and an organic phase comprising predominately N-alkylthiophosphoric triamide, tertiary amine, solvent and dissolved ammonia, and separating the resultant phases from each other.

15. A process according to claim 14 wherein ammonia along with a portion of the solvent are separated from said organic phase, and are compressed and cooled to form (i) a recycle mixture of liquid ammonia and solvent, and thereby also provide (ii) a concentrated residual product mixture comprising predominately N-hydrocarbylthiophosphoric triamide, and residual solvent and tertiary amine;

and wherein the recycle mixture is recycled for use as a portion of the ammonia feed to the second reaction chamber.

16. A process according to claim 15 wherein N-alkylthiophosphoric triamide and residual solvent and tertiary amine are separated from each other, and wherein separated residual solvent and tertiary amine are recycled for use as a portion of the feed for making the preformed mixture of a).

17. A process according to claim 14 wherein the heat of reaction from the mixture of a) is removed by continuously circulating a portion of the mixture of a) into a heat exchanger where heat is removed by a cooling medium and thence back to the first reaction chamber.

18. A process according to claim 14 wherein the heat of reaction from the mixture of a) is removed by controlling the pressure such that the mixture of a) boils and the vapors from said boiling mixture are condensed in a dephlegmator heat exchanger and refluxed back to the first reaction chamber.

19. A process according to claim 14 wherein the proportions of primary alkyl monoamine and tertiary amine in said preformed mixture are in a molar ratio range of 1:

1 to 1;

1.5 respectively, and the proportions of said preformed mixture and the thiophosphoryl chloride fed to the first reaction chamber are such that per mole of thiophosphoryl chloride there are in the range of about 0.95 to about 1.1 moles of primary alkyl monoamine and in the range of about 0.95 to about 1.5 moles of tertiary amine.

20. A process according to claim 14 wherein the reaction mixture in the first reaction chamber is continuously stirred/agitated by a mechanical stirrer/agitator, and wherein the preformed mixture and the thiophosphoryl chloride are both fed into such reaction mixture below the surface thereof and in close proximity to the stirrer/agitator to ensure rapid mixing of these feeds.

21. A process according to claim 14 wherein the heat of reaction from the mixture of b) is removed by continuously circulating a portion of the mixture of b) through a heat exchanger and thence back to the second reaction chamber.

22. A process according to claim 14 wherein b) is conducted at one or more pressures in the range of about 15 to about 100 psig.

23. A process according to claim 14 wherein said first and said second reaction chambers are heat exchangers that provide a residence time in the range of 1 to about 10 minutes and that provide sufficient heat exchange surface in contact with the reaction mixture to enable removal of the heat of reaction generated within said residence time.

24. A process according to claim 14 wherein:

1) the proportions of primary alkyl monoamine and tertiary amine in said preformed mixture are in a molar ratio range of 1;

1 to 1;

1.5 respectively, and the proportions of said preformed mixture and the thiophosphoryl chloride fed to the first reaction chamber are such that per mole of thiophosphoryl chloride there are in the range of about 0.95 to about 1.1 moles of primary alkyl monoamine and in the range of about 0.95 to about 1.5 moles of tertiary amine;

2) the reaction mixture in the first reaction chamber is continuously stirred/agitated by a mechanical stirrer/agitator, and the preformed mixture and the thiophosphoryl chloride are both fed into such reaction mixture below the surface thereof and in close proximity to the stirrer/agitator to ensure rapid mixing of these feeds;

3) b) is conducted at one or more pressures in the range of about 15 to about 100 psig;

4) ammonia along with a portion of the solvent are separated from said organic phase of d), and are compressed and cooled to form (i) a recycle mixture of liquid ammonia and solvent, and thereby also provide (ii) a concentrated residual product mixture comprising predominately N-hydrocarbylthiophosphoric triamide, and residual solvent and tertiary amine;

5) said recycle mixture is recycled for use as a portion of the ammonia feed to the second reaction chamber; and

6) N-alkylthiophosphoric triamide and residual solvent and tertiary amine of said concentrated residual product mixture are separated from each other, and separated residual solvent and tertiary amine are recycled for use as a portion of the feed for making the preformed mixture of a).

25. A process for the preparation of N-n-butylthiophosphoric triamide, which process comprises:

a) continuously feeding to and mixing in a first reaction chamber (i) a preformed mixture of n-butylamine, triethylamine and at least one liquid inert organic solvent, and (ii) thiophosphoryl chloride and removing heat of reaction at a rate sufficient to maintain the temperature of the reaction mixture in the range of about -20°

to about +50°

C., to produce a reaction mixture containing N-n-butylaminothiophosphoryl dichloride;

b) continuously feeding and mixing in a second reaction chamber (i) an effluent stream of reaction mixture formed in the first reaction chamber which effluent is withdrawn at a rate to maintain a substantially constant volume of reaction mixture in the first reaction chamber, and (ii) ammonia in proportions (1) that are at least about 16 moles of ammonia per mole of N-n-butylaminothiophosphoryl dichloride, (2) that produce a reaction mixture containing N-n-butylthiophosphoric triamide, and (3) that keep in solution substantially all of the ammonium chloride co-product formed in the reaction, and removing heat of reaction from the mixture formed in b) at a rate of removal such that the reaction mixture is at one or more temperatures in the range of about 5°

to about 50°

C. so that an appreciable amount of solid ammonium chloride-ammonia complex is kept from forming in said reaction mixture while avoiding a significant amount of N-n-butylthiophosphoric triamide decomposition;

c) withdrawing effluent from the second reaction chamber at a rate sufficient to maintain a substantially constant volume of reaction mixture in the second reaction chamber; and

d) enabling/causing the effluent from c) to separate into an inorganic phase comprising predominately ammonia, ammonium chloride and co-product thiophosphoric triamide, and an organic phase comprising predominately N-n-butylthiophosphoric triamide, tertiary amine, solvent and dissolved ammonia, and separating the resultant phases from each other.

26. A process according to claim 25 wherein ammonia along with a portion of the solvent are separated from said organic phase, and are compressed and cooled to form (i) a recycle mixture of liquid ammonia and solvent, and thereby also provide (ii) a concentrated residual product mixture comprising predominately N-n-butylthiophosphoric triamide, and residual solvent and triethylamine;

and wherein the recycle mixture is recycled for use as a portion of the ammonia feed to the second reaction chamber.

27. A process according to claim 26 wherein N-n-butylthiophosphoric triamide and residual solvent and tertiary amine are separated from each other, and wherein separated residual solvent and tertiary amine are recycled for use as a portion of the feed for making the preformed mixture of a).

28. A process according to claim 25 wherein the solvent in a) consists essentially of tetrahydrofuran, wherein the heat of reaction from the mixture of a) is removed by continuously circulating a portion of the mixture of a) into a heat exchanger where heat is removed by a cooling medium and thence back to the first reaction chamber.

29. A process according to claim 25 wherein the solvent in a) consists essentially of tetrahydrofuran, wherein the heat of reaction from the mixture of a) is removed by controlling the pressure such that the mixture of a) will boil and the vapors from said boiling mixture are condensed in a dephlegmator heat exchanger and refluxed back to the first reaction chamber.

30. A process according to claim 25 wherein the proportions of n-butylamine and triethylamine in said preformed mixture are in a molar ratio range of 1:

1 to 1;

1.5 respectively, and the proportions of said preformed mixture and the thiophosphoryl chloride fed to the first reaction chamber are such that per mole of thiophosphoryl chloride fed there are in the range of about 0.95 to about 1.1 moles of n-butylamine and in the range of about 0.95 to about 1.5 moles of triethylamine.

31. A process according to claim 25 wherein the reaction mixture in the first reaction chamber is continuously stirred/agitated by a mechanical stirrer/agitator, and wherein the preformed mixture and the thiophosphoryl chloride are both fed into such reaction mixture below the surface thereof and in close proximity to the stirrer/agitator to ensure rapid mixing of these feeds.

32. A process according to claim 25 wherein b) is conducted at a pressure in the range of about 18 to about 100 psig.

33. A process according to claim 25 wherein the heat of reaction from the mixture of a) is removed by continuously circulating a portion of the mixture of a) through a heat exchanger and thence back to the first reaction chamber, and wherein the heat of reaction from the mixture of b) is removed by continuously circulating a portion of the mixture of b) through a heat exchanger and thence back to the second reaction chamber.

34. A process according to claim 25 wherein said first and said second reaction chambers are heat exchangers that provide a residence time in the range of 1 to about 10 minutes and that provide sufficient heat exchange surface in contact with the reaction mixture to enable removal of the heat of reaction generated within said residence time.

35. A process according to claim 25 wherein the temperature of the reaction mixture in a) is maintained the range of about 0°

to about 10°

C., and wherein the amount of ammonia fed in b) is such that there are at least about 20 moles of ammonia per mole of N-n-butylaminothiophosphoryl dichloride.

36. A process according to claim 25 wherein the solvent in a) consists essentially of tetrahydrofuran, wherein the pressure in a) is maintained in the range of about 40 to about 60 mm Hg, wherein the temperature of the reaction mixture in b) is maintained the range of about 8°

to about 15°

C., and wherein the pressure in b) is maintained in the range of about 25 to about 30 psig.

37. A process according to claim 36 wherein the temperature of the reaction mixture in a) is maintained the range of about 0°

to about 10°

C., and wherein the amount of ammonia fed in b) is such that there are at least about 20 moles of ammonia per mole of N-n-butylaminothiophosphoryl dichloride.

38. A process according to claim 37 wherein the reaction mixture in the first reaction chamber is continuously stirred/agitated by a mechanical stirrer/agitator, and wherein the preformed mixture and the thiophosphoryl chloride are both fed into such reaction mixture below the surface thereof and in close proximity to the stirrer/agitator to ensure rapid mixing of these feeds.

39. A process according to claim 38 wherein the heat of reaction from the mixture of a) is removed by continuously circulating a portion of the mixture of a) through a heat exchanger and thence back to the first reaction chamber, and wherein the heat of reaction from the mixture of b) is removed by continuously circulating a portion of the mixture of b) through a heat exchanger and thence back to the second reaction chamber.

40. A process according to claim 38 wherein said first and said second reaction chambers are heat exchangers that provide a residence time in the range of 1 to about 10 minutes and that provide sufficient heat exchange surface in contact with the reaction mixture to enable removal of the heat of reaction generated within said residence time.