Claims
- 1. A process for preparing a compound of the formula ##STR4## wherein R is C.sub.3 to C.sub.6 alkyl; and
- R.sup.1 is C.sub.1 to C.sub.2 alkyl,
- comprising reacting formaldehyde with a compound of the formula ##STR5## in a water-based suspension in the presence of a base, the pH being just above 7 to about 11.5, the reaction temperature being about 5.degree. to 90.degree. C. and the base being selected from alkali metal carbonate, alkali metal hydroxide, alkaline earth metal hydroxide, tertiary amine, pyridine, dimethylaniline and anion exchange resin.
- 2. A process according to claim 1 wherein R is t-butyl and R.sup.1 is methyl.
- 3. A particulate, slow-release, surface-modified product made by treating an aqueous suspension of a compound of the formula ##STR6## wherein R is C.sub.3 to C.sub.6 alkyl; and
- R.sup.1 is C.sub.1 to C.sub.2 alkyl,
- in particulate form at a temperature of about 15.degree. to 90.degree. C. with a base to provide a pH of about 11 to 13.
- 4. A particulate product according to claim 3 made by treating the aqueous suspension with an alkali metal carbonate or hydroxide.
- 5. A particulate product according to claim 3 having a number average particle size of 1 to 20.mu. with 95% by number of the particles being 2 to 20.mu. in size.
- 6. A particulate product according to claim 3 wherein R is t-butyl and R.sup.1 is methyl.
- 7. A particulate, slow-release, surface-modified product made by treating an aqueous suspension of a compound of the formula ##STR7## wherein R is C.sub.3 to C.sub.6 alkyl; and
- R.sup.1 is C.sub.1 to C.sub.2 alkyl,
- in particulate form at a temperature of about 15.degree. to 90.degree. C. with a mineral acid to provide a pH of about 0.5 to 2.0.
- 8. A particulate product according to claim 7 made by treating the aqueous suspension with hydrochloric or phosphoric acid.
- 9. A particulate product according to claim 7 having a number average particle size of 1 to 20.mu. with 95% by number of the particles being 2 to 20.mu. in size.
- 10. A particulate product according to claim 7 wherein R is t-butyl and R.sup.1 is methyl.
- 11. A composition for the control of undesirable vegetation consisting essentially of a surface-modified particle of claim 3 and at least one of (a) a surface active agent, and (b) a solid or liquid diluent.
- 12. A composition for the control of undesirable vegetation consisting essentially of a surface-modified particle of claim 5 and at least one of (a) a surface active agent, and (b) a solid or liquid diluent.
- 13. A composition for the control of undesirable vegetation consisting essentially of a surface-modified particle of claim 6 and at least one of (a) a surface active agent, and (b) a solid or liquid diluent.
- 14. A composition for the control of undesirable vegetation consisting essentially of a surface-modified particle of claim 7 and at least one of (a) a surface active agent, and (b) a solid or liquid diluent.
- 15. A composition for the control of undesirable vegetation consisting essentially of a surface-modified particle of claim 9 and at least one of (a) a surface active agent, and (b) a solid or liquid diluent.
- 16. A composition for the control of undesirable vegetation consisting essentially of a surface-modified particle of claim 10 and at least one of (a) a surface active agent, and (b) a solid or liquid diluent.
- 17. A particulate product according to claim 6 made by treating the aqueous suspension with an alkali metal carbonate or hydroxide.
- 18. A particulate product according to claim 6 having a number average particle size of 1 to 20.mu. with 95% by number of the particles being 2 to 20.mu. in size.
- 19. A particulate product according to claim 10 made by treating the aqueous suspension with hydrochloric or phosphoric acid.
- 20. A particulate product according to claim 10 having a number average particle size of 1 to 20.mu. with 95% by number of the particles being 2 to 20.mu. in size.
CROSS-REFERENCE TO RELATED APPLICATION
This is a division of application Ser. No. 681,260 filed on Dec. 13, 1984 and issued on Sept. 30, 1986 as U.S. Pat. No. 4,,614,799.
US Referenced Citations (5)
Non-Patent Literature Citations (2)
Entry |
"Symposium on Controlled Release of Bioactive Materials, III", pp. 7 to 11, Peppermen, Jr. et al. (1979). |
Bann et al., Chemical Reviews, vol. 58, pp. 146 to 148 (1958). |
Divisions (1)
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Number |
Date |
Country |
Parent |
681260 |
Dec 1984 |
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