GB2136417A - Fungicidal N-formyl-N-hydroxy-alanine salts - Google Patents

Abstract

A new salt of N-formyl-N-hydroxy-alanine of the formula <IMAGE> in which @ is derived from a compound having fungicidal activity on its own, a fungicidal composition comprising a carrier and the above salt, a method for combatting fungus, the use of the salt as fungicide and a process for preparing the salt are described. The anionic component @ may be a nitrogen base containing e.g. a guanidine, morpholine or aza-cyclododecene moiety.

Description

SPECIFICATION N-formyl-N-hydroxy-alanine salts The present invention relates to a certain group of salts of N-formyl-N-hydroxy-alanine.

European patent application 57027 in the name of Applicant describes the fungicidally active compound N-formyl-N-hydroxy-alanine and a variety of derivatives showing fungicidal activity as well.

It has now been found that a group of certain derivatives from N-formyl-N-hydroxy-alanine which are not known from European patent application 57027 appear to show very good fungicidal activities.

The said group of certain derivatives from N-formyl-N-hydroxy-alanine are salts of this hydroxyamino acid of which the positive ion is derived from a compound having fungicidal activity on its own.

The present invention therefore provides a salt of N-formyl-N-hydroxy-alanine of general formula I.

in which Z is a compound having fungicidal activity on its own. Compounds of general formula I comprising one or more molecules crystal water are encompassed by formula I as well.

The fungicidally active compound Z is preferably a compound having at least one nitrogen atom which is convertible into an ammonium ion in order to render the compound suitable as a positive ion of the salt with formula (I).

The compound Z is preferably selected from the group consisting of dodecylguanidine, transtridecyldimethylmorfoline, 3-(4-tertiairbutylphenyl)-2-methyl-propyl-2,6-dimethyl morfoline and 1 ,1 7- diguanidino-9-azahepta-decane.

The present invention also provides a fungicidal composition which comprises a carrier and a salt as hereinbefore defined.

A composition according to the invention preferably contains from 0.5 to 95% by weight of active ingredient.

A carrier in a composition according to the invention is any material with which the active ingredient is formulated to facilitate application to the locus to be treated, which may for example by a plant, seed or soil, or to facilitate storage, transport of handling. A carrier may be a solid or a liquid, including a material which is normally gaseous but which has been compressed to form a liquid, and any of the carriers normally used in formulating fungicidal compositions may be used.

Suitable carriers have been described in European patent application 57027 on page 4, line 1 8 until page 6, line 4. Further reference is made to European patent application 57027 on page 6, line 5 until page 7, line 9 with respect to what kind of formulations are suitable in connection with the present invention.

In another aspect, the invention also provides a method for combating fungus at a locus, which comprises treating the locus, which may for example be plants subject to or subjected to fungal attack, seeds of such plants or the medium in which such plants are growing or are to be grown, with a fungicidally effective amount of a salt of N-formyl-N-hydroxy alanine as defined above. The present invention is of wide applicability in the protection of crop plants against fungal attack. Many organisms of the class Oomycetes are controlled. For example Phytophthora infestans, Bremia latucae, and Peronospora destructor. Typical crops which can be protected include tobacco, potato, tomato, lettuce and cocoa.The present invention is of particular value in the protection of vines against fungal disease, such as downy mildew, Plasmopara viticola, because of the ability of the active compounds to provide a protective effect in those parts of the fine plant remote from the site of application. Thus, if the upper surfaces of leaves of a vine are sprayed, the plant becomes more resistant to fungal attack not only on the leaf undersurfaces (translaminar protection) but also on the plant surface emerging after the treatment. The active material may also be effective when applied to the stem or roots of the plant(s) to be protected. The duration of such protection is normally dependent on the individual compound selected, and also a variety of external factors, such as climate, whose impact is normally mitigated by the use of a suitable formulation.

The compounds used in this invention can be synthesized by known procedures and preferably by a process as described in the following Examples.

EXAMPLE 1 Preparation of the dodecylguanide salt ofN-formyl-N-hydroxy-alanine comprising 1 molecule crystal water per molecule.

Dodecyl guanidine (1 mole) in ethanol (1 I.) was treated with N-formyl-N-hydroxy alanine (1 mole) in ethanol (1 I.) and the solution evaporated to yield a waxy solid which was recrystallised from ethanol/ether.

Yield: 60% m.p.: 104-1070C anal. calc: C 54.5%; H 10.0%; N 14.8% found: 54.0%; 9.9%; 14.9% EXAMPLE 2 Preparation of the trans-tridecyidimethylmoffoline salt of N-formyl-N-hydroxy-alanine comprising 1 molecule crystal water per molecule.

Trans-tridecyldimethylmorfoline (1 mole) in ethanol (1 I.) was treated with N-formyl-Nhydroxyanaline (1 mole) in ethanol (1 I.) and the solution evaporated to yield a milky-coloured oil.

Yield: quantative anal. calc: C61.6%; H 10.7%; N 6.25% found: 62.2%; 10.8%; 6.3% Further examples of compounds according to the invention are shown in Table 1.

TABLE 1

Compound of Example m n Z 3 1 1 cis-tridecylmethylmorfoline anal. calc. C 61.6%; H 10.7%; N 6.25% found: C 62.5% H 11.4% N 6.3 % 4 1 1 3-(4-tertiarybutylphenyl)-2-methyl- anal. calc. C 63.5%; H 8.8%; N 6.15% propyl-2,6-dimethylmorfoline found: C 63.6%; H 9.5%; N 6.2 % 5 0 3 1,17-diguanidino-9-azaheptadecane anal. calc: C 74.8% H 8.2%; N 18.6% found: C 45.1% H 8.8%; N 19.8% 6 0 1 1-amino-2-aza-cyclo-tridec-1-ene anal. calc: C 62.7%; H 10.7%; N 9.15% found: C 62.3%; H 10.9%; N 8.9 % 7 1 1 para-tertiarybutyl-2-methyl-3-(2,6-di- anal. calc: C 61.5%; H 8.55%; N 6.0% methyl)-morfoline-4-yl-propiophenone found: C 62.2%; H 8.90%; N 6.0% 8 1 1 trans-4-cylo-dodecyl-2,6-dimethyl- anal. calc: C 58.6%; H 10.2%; N 6.2% morfoline found: C 57.7%; H 11.3% N 5.6% 9 0 1 cis-4-cyclo-dodecyl-2,6-dimethyl anal. calc:C 63.8%; H 10.15%; N 6.75% morfoline found: C 61.4%; H 10.2%; N 6.6% The present invention will be further described with reference to the following Example.

EXAMPLE 10 Glasshouse Fungicide Evaluation The following tests which have been described in European patent application 57027 have been carried out.

a) Antisporulant activity against vine downy mildew (Plasmopara viticola; P.v.a.) b) Translaminar activity against vine downy mildew (Plasmopara viticola; P.v.t.) c) Activity against the vine grey mould (Butrytis cinerea; B.c) d) Activity against tomato late blight (Phytophthora infestans; P.i.p.) e) Activity against apple powdery mildew (Podosphaera leucotricha; P.l.) Tests which have not been described in European patent application 57027 but which have also been carried out in connection with the present invention are f) Activity against barley powdery mildew (Erysiphe graminis f.sp. hordei) Eg The test is a direct antisporulant one, using a foliar spray. Leaves of barley seedlings, cultivar Golden Promise, are inoculated by dusting with mildew conidia one day prior to treatment with the test compound.The inoculated plants are kept overnight at glasshouse ambient temperature and humidity prior to treatment. The plants are sprayed at a dosage of 1 kg. of active material per hectare using a track sprayer as described under a). After drying plants are returned to a compartment at ambient temperature and humidity for up to 7 days, followed by assessment. Assessment is based on the percentage of leaf area covered by sporulation compared with that on leaves of control plants.

g) Activity against peanut leaf spot (Cercospora arachidicola) Ca The test is an eradicant one using a foliar spray. The leaves of peanut plants are sprayed with an aqueous suspension of Cercospora spores containing 2 x 105 Cercospora spores/ml. two days prior to treatment with the test cbmpound. The inoculated plants are kept for two days in high humidity and then allowed to dry before spraying at a dosage of 1 kg of active material per hectare using a track sprayer, as described in a). After treatment the plants are kept at 26-280C in high humidity.

Assessments are made two weeks after treatment, and are based on the number of necrotic spots compared with that on control plants.

h) Activity against broad bean rust {Uromyces fabae) Uf The test is a direct eradicant one using a foliar spray. The leaves of broad bean plants, cultivar Aquadulce, are sprayed with an aqueous suspension containing 105 spores/ml 20-24 hours prior to treatment with the test compound. The inoculated plants are kept overnight in high humidity and then allowed to dry before spraying at a dosage of 1 kg of active material per hectare using a track sprayer, as described in a). After treatment the plants are kept at 1 8-200C and ambient glasshouse humidity.

Assessments are made 7 days after treatment and are based on the density of pustules compared with that on the control plants.

The extent of disease control in all the above tests is expressed as a rating compared with a diluent sprayed control according to the criteria:- 0 = less than 50% disease control 1 = about 5080% disease control 2 = greater than 80% disease control The following compounds were tested. Dodecylguanidine, trans-tridecyl dimethylmorfoline, cis tridecyldimethylmorfoline, 3-M"-tertiary butylphenyl)-2-methyl-propyl-2-6-dimethyl morfoline and 1,1 7-diguanidino-9-azeheptadecane.

FUNGICIDAL ACTIVITY Example Z P.v.a P.v.t B.c P.i.p P.I E.g C.a U.f 1 -dodecylguanidine 2 0 0 1 - 0 2 0 2 -trans-tridecyldimethyl morfoline 2 0 1 0 0 2 1 0 3 -cis-tridecyldimethyl morfoline 2 0 0 0 1 2 0 0 4 -3-(4-tertiarybutylphenyl)-2-methyl- 2 1 2 0 2 2 0 2 -propyl-2,6-dimethylmorfoline 5 1, 17-diguanidino-9-azeheptadecane 2 2 1 1 1 1 0 0 6 -1-amino-2-aza-cyclo-tridec-1-ene 2 2 1 0 0 1 0 0 7 -para-tertiarybutyl-2-methyl-3- 2 1 1 0 2 1 0 1 (2,6-dimethyl)-morfolino-4-ylpropiophenone 8 -trans-4-cyclo-dodecyl-2,6-dimethyl- 2 2 1 0 0 1 0 0 morfoline 9 -cis-4-cyclo-dodecyl-2,6-dimethyl- 2 2 0 0 0 2 0 0 morfoline

Claims (9)

1. A salt of N-formyl-N-hydroxy-alanine of general formula I

in which Z is a compound having fungicidal activity on its own.

2. A salt as claimed in claim 1 in which Z is a compound comprising at least one nitrogen atom which can be converted into a quaternary ammonium ion.

3. A salt as claimed in claim 1 or 2 in which Z is selected from the group consisting of dodecylguanidine, trans-tridecyl dimethylmorforline, cis-tridecyldimethylmorfoline, 3-(41-tertiary butylphenyl)-2-methyl-propyl-2, ,6-di methylmorfoline, 1,1 7-diguanidino-9-azaheptadecane, 1 mino-2 aza-cyclo-tridec-1 -ene, para-tertiarybutyl-2-methyl-3-(2,6-dimethyl)-morfolino-4-yl-propiophenone, trans-4-cyclo-dodecyl-2,6-di methyl-morfoline and cis-4-cyclo-dodecyl-2 6-dimethyl-morfoline.

4. A fungicidal composition which comprises a carrier and a salt as claimed in anyone of claims 1-3.

5. A method for combating fungus at a locus, which comprises treating the locus with a fungicidally effective amount of a salt as defined in any one of the claims 1-4.

6. A method as claimed in claim 5 in which the locus comprises plants subject or subjected to fungal attack, seeds of such plants or the medium in which the plants are growing or are to be grown.

7. A method as claimed in claim 6, in which said plants are vines.

8. The use as a fungicide of a salt of general formula I as claimed in any one of the claims 1-3.

9. A process for the preparation of a salt of general formula I which comprises reacting N-formyl N-hydroxy alanine with a fungicidally active compound Z comprising at least one N-atom which can be converted into a quaternary ammonium ion according to known procedures.

1 0. A process for the preparation of a salt of general formula I using a process as hereinbefore described with particular reference to the Examples.