N-(PHOSPHONO-ALKYL)GLYCINES AND N-(PHOSPHONO-ARYL)GLYCINES, THEIR APPLICATION AS HERBICIDES AND THEIR PRODUCTION

Abstract: The application provides a new group of active herbicides consisting of N-(phosphono-alkyl)glycines (NPAG) and N-(phosphono-aryl)glycines (NPARG) of formula HO-CO-NH-CHR-P(O)(OH)2 where R is a C2-C18 alkyl group or phenyl having 1-3 C1-C18 alkyl substituents. The compounds have enhanced penetration properties through the membranes of the leaves. To improve the penetration through the membranes of the leaves of weeds and to improve its action, the earlier known active herbicide, N-(phosphonomethyl)glycine (NPMG), was sprayed as a salt of a cation like isopropylamine and was mixed with a surfactant in order to improve its penetration. However, only 7-15 % of the active ingredient penetrated the membranes of the leaves. The introduction of alkyl or aryl groups into the NPMG molecule give a lipophilic character to the molecule without changing the geometry of the active functional sites of the molecule. In this way the action of the new family of molecules on the enzyme 5-enolpyruvylshikimic acid-3-phosphate (EPSP) synthase active in the shikimic acid synthesis is maintained. The application further provides a process for producing the new compounds, characterised by the use of the ester of iminodiacetic acid or ester of glycine, alkyl or aryl aldehyde and a phosphite diester, followed by hydrolysis and the removal of an acetyl group by oxidation in the first instance and only by hydrolysis in the second instance.

Description: N- ( PHOSPHONO-ALKYL ) GLYCINES AND N- ( PHOS PHONO- ARYL ) GLYCINES , THEIR APPLICATION AS HERBI CIDES AND THEIR PRODUCTION DESCRIPTION 1 . Product The molecule Λ/-(phosphonomethyl)glycιne was patented in 1972 as an herbicide With the growing concern about environment and health, efforts have been made to find new molecules , which in smaller quantities per hectar show the same efficacy In the present patent we present a new family of molecules, which have an improved lipophilic character, allowing them to penetrate more efficiently the membranes of the leaves of weeds The geometry of the active functional sites is kept from N- (phonsphonomethyl)glycιne which allows the same action on the EPSP synthase of the shikimic acid The phophilic character was improved by substituting one hydrogen atom by an alkyl or aryl group that we represent by R Λ/-(phosphonomethyl)glycιne Λ/-(phosphono-alkyl)glycιne or N-(phosphoπo-aryl)glycιne R may be any alkyl group linear or not, containing 2 - 18 carbon atoms R may also be an aryl group containing one benzene ring and any alkyl groups substituting one or more ortho, meta or para positions of the benzene ring Each alkyl group may have 1 - 18 carbon atoms We found different herbici al activities in these molecules and found that the R group being a linear propyl group was especially efficient as herbicide. 2 . Production Process Two processes to produce Λ/-(phosphonomethyl)glycine are in industrial use: the process in organic 1 solvent and the process in water 2,3 as a solvent. The process with an organic solvent uses is a first step, as reagents, the ester of glycine, triethylamine and paraformaldehyde to produce the enamine. This enamine reacts in a second step with the ester of phosphorous acid. The product so obtained is hydrolysed to give the final product. The process with water as a solvent uses in a first step the sodium salt of iminodiacetic acid and phosphorous trichloride. In a second step paraformaldehyde is added in order to obtain N-(phosphonomethyl)iminodiacetic acid, which is filtered from the suspension. In a third step the Λ/-(phosphonomethyl)iminodiacetic acid reacts with an oxidant to eliminate one of the acetyl groups and to produce the ΝPMG. The first process can be used for the production of Λ/-(phosphono-alkyl)glycine (ΝPAG), but have the disadvantage that the enamine may react with the carbon atom in alpha position of the aldehyde function, before the phosphite is added. The phosphite may not be added before the enamine is formed, because then the nitrogen atom would be substituted in 3 valences and a mixture would be obtained. However this reaction can be avoided with the use of only one equivalent of aldehyde and adequate reactions conditions. The second process can not be used because the alkyl or aryl aldehydes are not soluble in water. This process is used for formaldehyde because formaldehyde is soluble in water. We propose now a process in three steps: - in an organic solvent the ester of iminodiacetic acid, triethylamine and the ester of phosphorous acid are added. Then the alkyl aldehyde is introduced. In this way only one molecule of the alkyl aldehyde will be added to the nitrogen atom, and the alkyl aldehyde is soluble. - the esther of N-(phosphono-alkyl)iminodiacetic acid (NPAIDA) is hydrolysed. - the NPAIDA is oxidized using water as a solvent and a suitable oxidant and catalyst. In this way the NPAG is obtained in good yield. EXAMPLES Example 1- Synthesis of NPBG In a 500 ml glass stirred flask was added: Tetrahydrofuran (THF) 5 mole Glycine methyl ester 0.25 mole To this solution was added slowing: Butyraldehyde 0.25 mole The solution was stirred at 0°C for 20 minutes. It was added: Diethyl ester of phosphorous acid 0.25 mole After 5 hours of stirring at reflux temperature, the reaction mixture was evaporated. In a 0,5 litter glass flask was added: Water 10 mole Sodium hydroxide 0.75 mole The ester of the previous reaction The mixture was heated under reflux 5 hours. Then it was cooled. The pH was adjusted to 1 ,5 with hydrochloric acid 10%. After 12 hours the suspension was filtered and NPBG obtained with 80 % of yield. Example 2 Synthesis of NPBG In a 500 ml glass stirred flask was added: Ethanol 5 mole Diethyl ester of iminodiacetic acid 0.25 mole Triethylamine 0.25 mole Diethyl ester of phosphorous acid 0.25 mole The solution was heated at reflux temperature and was added: Butyraldehyde 0.35 mole After 4 hours, the solution was distilled to eliminate the ethanol and water. In a 0,5 litter glass flask was added: Water 10 mole Sodium hydroxide 0.75 mole The ester of the previous reaction The mixture was heated under reflux 5 hours. Then it was cooled. The pH was adjusted to 1,5 with hydrochloric acid 10%. After 12 hours the suspension was filtered and NPAIDA obtained. In a stainless steel one-litter reactor was introduced: Water 10 moles NPAIDA 0.25 mole Hydrogen peroxide 1.0 mole Iron II sulphate 0.01 mole After heating to reflux, the suspension was filtered and NPAG obtained with 92% yield. BIBLIOGRAPHY 1. United States Patent, 4,389,349 (1983). 2. United States Patent, 3,950,402 (1976). 3. United States Patent, 3,794 ,758 (1974).

Claims: We claim: 1 st The molecule N-(phosphonobutyl)glycine and its use as a herbicide. 2 nd A product according to 1 st claim, where instead of butyl, an alkyl group is used with 2 - 18 carbon atoms, linear or not. 3 rd A product according to 1 st claim, where instead of butyl an aryl group is used, where the aryl group contains one benzene ring and one, two or three substitutions in o, m, p positions. Each substituting alkyl group may have 1 - 10 carbon atoms. 4 th A production process for the products in the ^,2™* and 3 rd claims, characterized by starting from esthers of iminodiacetic acid or esthers of glycine, esther of phosphorous acid, alkyl or aryl aldehyde in organic solvent. 5 th A production process according to 4 th claim, where the reaction temperature may be ambient to 150°C, preferably 50* to 110°C. 6 th A production process according to 4 th claim, where the esther of Λ/-(phospnono-alkyl or aryl)glycine or the esther of Λ/-(phospnono-alkyl or aryl)iminodiacetic acid ( NPAIDA) are hydrolysed by any known process by those skilled in the art. 7 th A production process according to 4 th claim, where the NPAIDA is oxidized to NPAG using water as solvent and any peroxyde and or without iron II or III salt as a catalyst. 8 th A production process according to 4 th claim, where the oxidation of NPAIDA using water as a solvent and uses oxygen pure or mixed with air in any proportions. 9 th A production process according to 8 th claim, where the catalyst is activated coal containing or not one or several of the metals palladium, platinum, rhodium, iron, cooper, tungsten, nickel. 10 th A production process according to 9 th claim, where the temperature may be 50 - 150°C and the pressure 1 - 10 bar.

Inventors: BENTO M DE SA PEREIRA MARIA FL, BRITO CORREIA PEDRO, BENTO M. DE SA PEREIRA, MARIA, FLORBELA, BRITO CORREIA, PEDRO
Applicants: BENTO M DE SA PEREIRA MARIA FL, BRITO CORREIA PEDRO, BENTO M. DE SA PEREIRA, MARIA, FLORBELA, BRITO CORREIA, PEDRO
Application year: 2001
Main classification: C07F9
IPC codes: A01N57, C07F9