HK1036282B - Fungicides - Google Patents

Description

Fungicidal agents

the present invention relates to novel compounds having fungicidal activity.

One aspect of the present invention provides a compound having the structure dimethyl [3- (propoxycarbonylamino) propyl ] ammonium O-ethylphosphonate

The compounds according to the invention have fungicidal activity, in particular against Phytophthora infestans, such as grapevine peronospora (Plasmopara viticola), Phytophthora blight (such as tomato or potato late blight (Phytophthora infestans)), Pythium, myceliophthora (Aphanomyces spp), Bremia (Bremia spp), Peronospora (Peronospora spp) and Pseudoperonospora (Pseudoperonospora spp).

Thus, the present invention also provides methods of controlling fungi in fungal infections or where infections are likely. The method comprises applying a compound of formula I at the site.

The present invention also provides an agricultural composition comprising a compound of formula I in admixture with an agriculturally acceptable diluent or carrier.

The compositions of the invention may also contain one or more additional active ingredients, such as compounds known to have plant growth regulator, herbicide, fungicide, insecticide or acaricide properties. Alternatively, the compounds of the present invention may be used sequentially with other such active ingredients.

Fungicides which can be mixed with the compounds include acylanilides, such as metalaxyl, oxadixyl, methylfuroamide, benalaxyl and furalaxyl; cymoxanil; mancozeb; chlorothalonil; sterilizing pill; captan; famoxadone; fenamidone; spiroxamine; fluazinam; dimethomorph; strobilurins, such as kresoxim-methyl, azoxystrobin and trifloxystrobin, pyrimethanil, cyprodinil; mepanipyrim and iprodione.

The names cited for these compounds are non-patent generic names, and their chemical structures can be found in the "handbook of pesticides" (eleventh edition), published by the british crop protection association in 1997. No compounds of the generic name are listed in the pesticide handbook, the complete chemical names are as follows:

trifloxystrobin- (E, E) -methoxyimino- {2- [1- (3-trifluoromethylphenyl) -ethylideneaminooxymethyl

Yl ] phenyl } acetic acid methyl ester

spiroxamine-8-tert-butyl-1, 4-dioxaspiro [4, 5] decan-2-ylmethyl (ethyl) (propyl) amine

fenamidone- (S) -1-anilino-4-methyl-2-methylthio-4-phenylimidazoline-5-one

The compositions of the invention may, for example, contain dispersing agents, emulsifying agents or wetting agents. They are usually aqueous concentrates.

When applied to plants, the concentration of active ingredient in the compositions of the invention is preferably from 0.0001 to 1.0% by weight, more preferably from 0.0001 to 0.01% by weight. The amount of active ingredient in the primary composition may vary within wide limits, for example from 5 to 95% by weight of the composition.

In the methods of the invention, the compounds are typically applied to the seed, plant or their growing environment. Thus, the compounds of the invention can be applied directly to the soil before, at or after sowing, so that the active compounds present in the soil are able to control the growth of fungi which may attack the seed. When the soil is treated directly, the active compound can be applied by any method which allows it to be mixed thoroughly with the soil, such as spraying, spreading solid particles, or applying the active ingredient simultaneously during sowing. Suitable application rates are from 5 to 1000 g/ha, preferably from 10 to 500 g/ha.

As a protective measure, the active compounds can be applied directly to the plants, for example by spraying or dusting, when the fungi start to appear on the plants or before they appear on the plants. In both cases, the preferred mode of application is foliar spraying. It is generally important to obtain good control of fungi at an early stage of plant growth, as plant damage is most severe at this stage. If desired, the spray or dusting powder will generally contain a pre-emergent or post-emergent herbicide. In some cases, it is desirable to treat the roots of the plants prior to or at the time of planting, for example by immersing the roots in a suitable liquid or solid composition. When the active compounds are applied directly to the plants, suitable application rates are from 0.025 to 5 kg/ha, preferably from 0.05 to 1 kg/ha.

Compounds of formula I can be prepared by reacting amines of formula II

And reacting with ethyl hydrogen phosphonate.

The reaction may be carried out in aqueous solution.

The present invention will be described with reference to examples.

Example 1

A solution of ethyl hydrogen phosphonate sodium salt (13.2 g of sodium salt dissolved in 25 ml of water) was added to an aqueous solution of 3- (dimethylamino) propylcarbamate propyl hydrochloride (31.0 ml, concentration 722 g/l, 0.1 mol). The solution was evaporated to dryness leaving an oil containing white sodium chloride solid. The crude product was triturated with dichloromethane (ca. 100 ml) and the insoluble white solid (sodium chloride) was filtered off and washed with several portions of dichloromethane. The filtrates were combined and evaporated to leave dimethyl [3- (propoxycarbonylamino) propyl ] ammonium O-ethylphosphonate as a viscous colorless oil.

NMR spectra confirmed the salt by observing chemical shifts relative to propyl 3- (dimethylamino) propylcarbamate.

The starting material was prepared by alkaline hydrolysis of diethyl phosphite by known methods. See, for example, Synthesis 134, 1978.

Example 2

Aqueous solutions of the compound of example 1 at various concentrations were sprayed on the grapevines tested with a hand sprayer. The plants were then inoculated by spraying a spore suspension containing 100000 Plasmopara viticola spores per ml with a hand sprayer. For comparison, commercially available propionamide (propamocarb) hydrochloride was also sprayed on grapevine.

The extent of disease control was evaluated in comparison to the untreated plants.

The results are as follows:

control agent	Concentration (ppm)	% control
			Compounds of the invention	800	81.5
Compounds of the invention	400	27.6
			Propionamide hydrochloride	800	14.6
Propionamide hydrochloride	400	4.2

Claims (1)

1. Dimethyl [3- (propoxycarbonylamino) propyl ] ammonium O-ethylphosphonate having the structure: