DE2555573A1 - PROCESS FOR THE PRODUCTION OF N- (PHOSPHONOMETHYL) -GLYCINE - Google Patents

Description

DR. BERG D'PL.-ING. STAPF 25 5 5 ^Γ 7 ⁿ

DIPL.-ING. SCHWABE DR. DR. SANDMAIR QOOfO

PATENT LAWYERS

8 MUNICH 86, POST BOX 8602 45

Attorney's file 26 592 1 0. DEl. 1975

Monsanto Company, St. Louis / USA

"Process for the production of N- (Phosphonmethyl) -

glycine "

This invention relates to a process for the production of U- (phosphonomethyl) glycine by reducing carbonylaldimine methane phosphonate. The Carbonylaldiminmethanphosxhonate are by reaction of glyoxylic acid esters or Glyoxal made with aminomethane phosphonic acid esters.

^AS - ¹⁰⁰⁹ 609825/1010

8 Munich 80, Mauerkircherstraße 45 Banks: Bayerische Vereinsbank Munich 453100

Telegrams: BERGSTAPFPATENT Munich Hypo-Bank Munich 3892623

TELEX: 05 24 560 BERG d Postscheck Munich 653 43 - 808

It is known that U- (phosphonomethyl) -glycine by oxidation of Ef- (Phosphonmethyl ^ iminodiacetic acid either can be produced electrolytically or by means of chemical oxidation.

It has now been found that N- (phosphonomethyl) -glycine by means of catalytic reduction of carbonylaldimine methanephosphonic acid esters and subsequent hydrolysis of the esters can be produced.

Each the process of the invention is prepared Ή- (phosphonmethyl) -glycine in such a way that one. Aminomethylphosphonic acid compound of the general formula

(I) H ₂ Ii - CH ₂ P

0 OX

Ii

OY

wherein the radicals X and T, independently of one another, are hydrogen or are lower alkyl groups, with an aldehyde of the general formula

0 0

^{11 M.}

(II) Z-C-C-H,

wherein Z is a hydrogen atom, a hydroxyl or lower alkoxyl group is to form an carbonylaldimine methane phosphonate the general formula

-3- 609825/10 10

OH 0

II t I!

(III) ZGC = H-CH ₂ P

ου

wherein X, Y and Z have the meaning defined above, reacts, and then the carbonylaldimine methane phosphonate Formation of a compound of the general formula, 0 H

K I

ZC-CH ₂ -H-CH ₂ -P

wherein X, Y and Z have the meanings defined above, hydrogenated.

When Z is hydrogen, the compound is treated with an oxidizing agent, either before or after the hydrogenation step, to convert the aldehyde into a carboxylic acid. When there are alkoxyl groups, they become hydroxyl groups hydrolyzed using an acid such as hydrohalic acid, sulfuric acid and the like.

In particular, the process of this invention is carried out by using a mixture of aminomethane phosphonate and glyoxal or glyoxylic acid or its ester in a solvent forms the mixture to a sufficient level heated elevated temperature to initiate the condensation reaction and the water of reaction removed, where-

-4-60982b / 1010

by obtaining carbonylaldimine methanephosphonate.

The Carbonylaldiminmethanphosphonat is then oxidized _t \ when Z is hydrogen to form a Carboxyaldiminmethanphosphonats. The carbonyl or carboxy aldimine methane phosphonate is then hydrogenated using hydrogen with a hydrogenation catalyst, such as a noble metal catalyst, and U- (phosphonomethyl) glycine or its ester is obtained. The ester groups are hydrolyzed to form N- (PhOsphonmethyl) -glycine.

When performing the initial condensation stage of the process this invention, it is preferable to use a solvent in which the reactants and the Reaction product are soluble. Usable solvents are the aromatic hydrocarbons such as benzene, Toluene, xylene and the like.

Under the names "IT-lower alkyl" and "IT-lower alkoxyl", As used herein, alkyl and alkoxyl groups are understood to contain 1 to 5 carbon atoms. The alkyl and alkoxyl groups are, for example, methyl, ethyl, propyl, butyl, pentyl groups and the like and their isomers and ethoxyl, ethoxyl and pentoxyl groups and the isomers of such alkoxyl groups. In carrying out the condensation step in the process of this invention, it is preferred to use Liolarver-

-5-

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To use ratios of glyoxal or glyoxylic acid or ester to aminomethylphosphonate of at least 1 to 1. More "preferred is molar ratios of 1.5 to 2 to T to use.

In carrying out the condensation step of the process of this invention, the reaction temperature can range from 0 to HO ⁰ C or even higher. It is preferred, to facilitate the reaction and to achieve a better rate, that the process of this invention be carried out at temperatures from about 50 to about 115 ° C., and preferably at the reflux temperature of the particular solvent used.

To hydrogenate the Aldiminmethylenphosphonat «intermediate product according to the process of this invention, one can use gaseous hydrogen and a hydrogenation catalyst, this being either supported on an inert support or a finely divided metal catalyst such as Raney-JTickel, Raney-Cobalt, Mladium, platinum, rhodium, iridium and like is ₀

The amount of metal catalyst used can be widely Range, depending on the desired rate of hydrogenation, vary. Metal catalysts can therefore be used in amounts of 0.001 to 20 or more parts by weight per 100 parts by weight of carbonyliminomethane phosphonate. IJm

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to facilitate the response and for reasons of expediency it is preferably from 0.01 to 0.1 parts by weight of the catalyst per 100 parts by weight carbonyliminomethane phosphonate to use.

In carrying out the hydrogenation step of the process of this invention the temperature can vary widely, i.e. from O C or below up to 150 C or higher and it can be of the Hydrogen pressure in the range of 1 to 100 atmospheres or even higher. For convenience it is preferred to use temperatures in the range of 0 to about 75 C and hydrogen pressures from 1 to 100 atmospheres or higher to use. Hydrogen pressures of 1 to 10 atmospheres are particularly preferred.

The reaction time in 3 ^{e (} * er of the steps of the process of the invention is not critical and can vary from times as short as 1 minute to times as high as 40 minutes or even more Reaction time and reaction temperature can vary.

The H- (phosphonomethyl) glycine produced according to this invention is valuable as a post-emergence herbicide

The following examples serve to further illustrate the invention. All parts are weight parts, be it because that this is stated otherwise.

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example 1

To a solution of 13.0 g (0.10 mol) of n-butyl glyoxylate Diethylaminomethylphosphonate (8.3 g, 0.05 mol) is added to 100 ml of toluene with stirring and the mixture is heated, whereby the water of condensation is removed by means of azeotropic distillation. The reaction is in less than 15 minutes completed.

The toluene is removed in vacuo in a rotary evaporator and an amber-colored oil is obtained as a residue. The amber oil was distilled in a molecular distillation ionskolonne with purified walls at 150 171 ⁰ C (Wandung3temperatur) and a pressure of 5 to 23 / to. A yellow oil distillate (6.9 g) is obtained. This ga-be oil was redistilled in a Hickman molecular distillation column (with magnetic stirring) to give a fraction} boiling point 134-137 ⁰ C at 12 - 13 / um n ^ ² 1.4514 and the following analysis.

Calculated for C ₁₁ H ₂₂ NO ₅ P: P = 11.09 found: P = 11.22

This material was called diethyl carbonate n-butoxyaldiminomethane phosphonate identified.

On a second try where you only get a $ 25 If an excess of n-butyl glyoxylate is used, a 45% yield of less pure product is obtained.

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Example 2

To a solution of diethylaminomethane phosphonate (8.3 g or 0.050 mol) in 100 ml of toluene is added 40% aqueous Glyoxal (3.6 g or 0.025 mole). A mildly exothermic reaction was observed after which the mixture was heated to reflux and the water is removed by azeotropic distillation .

After removal of the loluols with subsequent molecular distillation in a purified distillation column at 150-152 ⁰ C (wall temperature) and 5-29 / to pressure are obtained 2.0 g of a light yellow oil nj 1.4575, which is identified as Diäthylformylmethyleniminomethanphosphonat.

Analysis:

Calculated for C ₇ K ₁₄ IiO ₄ P: P = $ 14.95

found: P = 15.24 i °

Example 3

The aldimino ester obtained in Example 1 is dissolved in 5 times its volume in ethanol and gives 1 wt. $ Add 10% palladium on charcoal catalyst to the solution in a stainless steel pressure vessel. The pressure vessel vent until the ethanol begins to distill, then slowly passes hydrogen through until the pressure is reached 7.0 kg / cm is reached. The shaker is turned on, whereby the pressure falls to a stable value; heats the reactor to 50 ° C, re-establish a pressure of 7.0 kg / cm until the pressure remains stable.

—9—

6 0 9 8 2 b / 1 0 1 Q

The reactor is cooled, the pressure is released and the solution is filtered to remove the catalyst and concentrated, The oil obtained as residue, the n-butyl-! T- (diethoxyphosphinylmethyl) glycinate contains is sufficiently pure for hydrolysis. N-Butyl-I- (diethoxyphosphinylmethyl) -glycinate hydrolyzed by heating it with an excess of concentrated hydrobromic acid, after which the product is concentrated and separated by crystallization. The product is ET- (Phosphonmethyl) -glycine.

Example 4

A solution of 24 g (0.20 mol) of silver nitrate in 100 ml Water is treated with a sodium hydroxide solution (16 g) in 15 ml / water. To this suspension of brown silver oxide are added, with cooling, in small portions at 15 to 20 ° C., diethylformylmethyleneiminomethane phosphonate (20.7 g). After brief stirring, the solution is filtered to precipitate metallic silver and the filtrate is carefully acidified with dilute hydrochloric acid to Ρττ 3.

By concentrating the solution and drying by azeotropic distillation with ethanol, followed by filtration to remove the sodium nitrate one obtains the crude unsaturated acid diethyl carboxyaldimine methane phosphonate.

1 g of 1Obiges palladium is added to the above solution Charcoal in a stainless steel pressure vessel.

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- ίο -

The pressure vessel is closed and vented until the ethanol begins to evaporate. Hydrogen is passed into the pressure vessel up to a reading of 8 kg / cm, the shaker is turned on and the reaction is allowed to proceed until the pressure has stabilized. The reaction is ended by adjusting the pressure again and heating to 50 ^{° C.}

The pressure is released from the vessel and the mixture is filtered to remove the catalyst. The 3? Filtrate is concentrated and filtered again and then brought to dryness, whereby the crude saturated carboxylic acid, which contains some ester, but this is satisfactory for hydrolysis. The above acid (ester) is heated with 4S in excess of hydrogen bromide until the hydrolysis has taken place. The solution was concentrated and then crystallized to give N- (phosphonomethyl) glycine.

Patent claims:

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Claims (9)

- 11 claims: 1.! Process for the production of U- (Phosphonmethyl) -glycine the general formula X-O OHO \ 8th ! Il P-GH ₉ -H-GH-CZ, Y- (T wherein the radicals X and Y, independently of one another, are hydrogen or I-lower alkyl groups and Z is hydrogen or
IT-lower alkoxyl groups are characterized in that a carbonylaldimine methanephosphonic acid compound of the general formula
XO 0 0 Il Il P - GH ₂ K = CH C - Z, Y- (T wherein X, Y and Z have the meanings defined above,
brings into contact with hydrogen in the presence of a hydrogenation catalyst, whereby the carbonyliminomethanephosphonic acid compound is reduced to the 1- (phosphonmethyl) -glycine compound. 2. The method according to claim 1, characterized that you can take the reaction 609825/10 10 2Ä55573 Printing. 3. Terfahren according to claim 2, dad u'r c h g e -indicates that one is a hydrogen pressure tone 1 used in tOO atmospheres. 4. Terfahrtn according to claim 3 _f thereby ge ke.nnieiöhnet that one has a hydrogen pressure 1 to 10 atmospheres used 5. terfahren according to claim 1, characterized in that one is used as the hydrogenation catalyst Laney-lfickel, Haney-Cobalt, Platinum, Palladium, Rhodium. Used iridium. 6 * terfahr · η according to claim 5, characterized in that the hydrogenation catalyst iftlladium is used. 7 · Terfahren according to claim 6, characterized in that ■ that the carbonylaldiminaethanphoephonaic acid compound is a Kledrigalkoxylester used. 8 .. Terfahren according to claim 7 »characterized in that the hydrogenation product hydrolyzed to N- (phosphonaethyl) glycine. 60982b / 10iO 21155573 9. The method according to claim. 7, characterized that one as Carbonylaldiminmethanpho sphonic acid compound diethyl carbon-n-but oxyaldimine methane phosphonate used. ORiGlNAL INSPECTED
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