Claims
- 1. A method of making a monomer of tetraalkyl vinylidene-1, 1-diphosphonate, comprising the steps of:
- (a) combining a secondary amine, a formaldehyde and a tetra (alkyl) methylene diphosphonate to form a first aqueous mixture;
- (b) maintaining the pH of said aqueous mixture above about 6 while reaction occurs in said mixture; and
- (c) refluxing said aqueous mixture to obtain a refluxed product of said monomer of tetraalkyl vinylidene-1, 1-diphosphonate.
- 2. The method as defined in claim 1 wherein said secondary amine is first combined with water to form an aqueous amine solution and said amine solution is next mixed with said formaldehyde and said tetra (alkyl) methylene diphosphonate to form said first aqueous mixture.
- 3. The method as defined in claim 1 wherein said tetra (alkyl) methylene diphosphonate is selected from the group consisting of tetra (methyl), tetra (ethyl), tetra (propyl) and tetra (isopropyl) methylene diphosphonate.
- 4. The method as defined in claim 1 wherein said secondary amine comprises at least one of dipropylamine, diethylamine and dimethylamine.
- 5. The method as defined in claim 1 wherein said formaldehyde is selected from the group consisting of formalin, a paraformaldehyde and trioxane.
- 6. The method as defined in claim 1 wherein said pH is about 7.35-7.40.
- 7. The method as defined in claim 1 wherein said step (c) is performed in about two hours time.
- 8. The method as defined in claim 1 further including a purification step for processing said reflexed product.
- 9. The method as defined in claim 8 wherein said purification step comprises:
- (1) adding toluene and acid to said refluxed product to form a mixture;
- (2) refluxing said mixture of toluene, acid and said refluxed product; and
- (3) evaporating and distilling unwanted portions of said refluxed mixture to form a purified monomer of tetraalkyl vinylidene-1, 1-diphosphonate.
- 10. The method as defined in claim 9 wherein said monomer is isolated with about 97% purity.
- 11. The method as defined in claim 9 wherein said monomer has a vinylidene:MDA ratio range of about 3.4 to 96.6 to 7 to 3.
- 12. The method as defined in claim 1 wherein said pH ranges from about 6 to 14.
- 13. A method of making a monomer of tetraalkyl vinylidene-1, 1-diphosphonate, comprising the steps of:
- (a) combining a secondary amine with water to form an aqueous amine solution;
- (b) combining a formaldehyde and a tetra (alkyl) methylene diphosphonate with said aqueous amine solution to form a first aqueous solution;
- (c) adjusting pH of said first aqueous solution to be between about 6 and 14;
- (d) refluxing said first aqueous solution for about 3 hours to form a refluxed product; and
- (e) purifying said refluxed product to produce said monomer.
- 14. The method as defined in claim 13 wherein said pH is about 6.85 to 7.45.
- 15. The method as defined in claim 13 wherein said formaldehyde is selected from the group consisting of formalin, paraformaldehyde, and trioxane.
- 16. The method as defined in claim 13 wherein said tetra (alkyl) methylene diphosphonate comprises at least one of tetra (methyl), tetra (ethyl), tetra (propyl) and tetra (isopropyl) methylene diphosphonate.
- 17. The method as defined in claim 13 wherein said secondary amine is selected from the group consisting of dipropylamine, diethylamine and dimethlylamine and higher order amines.
- 18. The method as defined in claim 13 wherein the ratio range of said monomer to said tetra (alkyl) methylene diphosphonate is about from 3.4 to 96.6 to about 7 to 3.
- 19. The method as defined in claim 13 wherein the upper ratio of said monomer to said tetra (alkyl) methylene diphosphonate is about 9 to 1 if distillation during purification is performed at very high vacuum less than about 0.01 mm Hg.
- 20. A method of making a monomer of tetraalkyl vinylidene-1, 1-diphosphonate, comprising the steps of:
- (a) combining a secondary amine, a formalin and a tetra (alkyl) methylene diphosphonate to form a first aqueous mixture; and
- (b) refluxing said aqueous mixture to obtain a refluxed product of said monomer of tetraalkyl vinylidene-1, 1-diphosphonate.
- 21. The method as defined in claim 20 wherein a secondary amine hydrochloride is further added in said step (a).
- 22. The method as defined in claim 20 wherein said secondary amine comprises about 0.1-1.0 moles.
- 23. The method as defined in claim 30 wherein said formalin is varied from about 0.1-1.0 moles.
Government Interests
This invention was made with government support under Contract No. 00222401 awarded by The Department of Energy. The government has certain rights in this invention.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3686290 |
Carroll |
Aug 1972 |
|
4939284 |
Degenhardt |
Jul 1990 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
1204967 |
May 1967 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Charles R. Degenhardt & Don C. Burdsall, "Synthesis of Ethenylidenebis (phosphonic acid) and Its Tetraalkyl Esters", J. Org. Chem. 1986, 51, 3488-3490. |
Lehnert, W. Tetrahedron 1974, 30, 301-305. |