Abstract:
There are provided fungicidal 2,2-diaryl-1-(oxa and thia)-2a-azonia-2-borataacenaphthene compounds having the structural formula ##STR1## Further provided are compositions and methods comprising those compounds for the protection of plants from fungal infestation and disease.

Description:
BACKGROUND OF THE INVENTION 
     Phytopathogenic fungi are the causal agents for many diseases that infect and destroy crops. In particular, the diseases sugar beet cercospora leaf spot, apple scab, tomato early blight and grape and pepper botrytis are especially devastating. 
     Sugar beet is susceptible to many foliar diseases caused by phytopathogenic fungi. One of the most frequently encountered and destructive foliar diseases occurring on sugar beet is sugar beet cercospora leaf spot, caused by the fungus, Cercospora beticola. Sugar beet cercospora leaf spot is common to sugar beet plants throughout the world, and is particularly destructive in regions with wet, warm growing seasons, such as Western and Southern Europe, and the Midwestern United States. During periods of high temperature and wetness, sugar beet cercospora leaf spot spreads rapidly in the field. Ultimately, the disease kills sugar beet leaf tissue, resulting in reduced sugar beet weight and sugar content. 
     The leaves and fruit of apple trees are susceptible to attack by a fungus, Venturia inaequalis, resulting in a disease called apple scab. The disease is most common in the United States and Europe. Uncontrolled, apple scab results in deformed, low quality fruit. 
     In spite of the commercial fungicides available today, diseases caused by fungi still abound. Accordingly, there is ongoing research to create new and more effective fungicides for controlling or preventing diseases caused by phytopathogenic fungi. 
     It is therefore an object of the present invention to provide a method for the prevention, control or amelioration of a disease caused by a phytopathogenic fungus. 
     It is also an object of the present invention to provide a method for the protection of a plant, plant seed or tuber from fungal infestation and disease. 
     These and other objects of the present invention will become more apparent from the detailed description thereof set forth below. 
     SUMMARY OF THE INVENTION 
     The present invention describes fungicidal 2,2-diaryl-1-(oxa and thia)-2a-azonia-2-borataacenaphthene compounds. 
     The fungicidal 2,2-diaryl-1-(oxa and thia)-2a-azonia-2-borataacenaphthene compounds of the present invention have the following structural formula: ##STR2## wherein X and Y are each independently hydrogen, halogen, C 1  -C 6  alkoxy, C 1  -C 6  haloalkoxy, C 1  -C 6  alkyl or C 1  -C 6  haloalkyl; 
     m and n are each independently an integer of 0, 1, 2 or 3; 
     A is O or S; 
     R, R 1 , R 2 , R 3 , R 4  and R 5  are each independently hydrogen, halogen, C 1  -C 4  alkoxy, C 1  -C 4  haloalkoxy, C 1  -C 4  alkyl, C 1  -C 4  haloalkyl, C 1  -C 4  hydroxyalkyl, cyano, nitro, CH 2  CN, hydroxy, NR 6  R 7 , SO 3  R 8  or COR 9  ; 
     R 6 , R 7  and R 8  are each independently hydrogen or C 1  -C 4  alkyl; and 
     R 9  is C 1  -C 4  alkyl. 
     This invention also relates to compositions and methods comprising those compounds for the prevention, control or amelioration of diseases caused by phytopathogenic fungi. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Phytopathogenic fungi are the causal agents for many diseases that infect and destroy agronomic crops, both growing and harvested. In the United States alone, agronomic crops must compete with about 18,000 species of fungi. 
     Advantageously, the present invention provides a method for the prevention, control or amelioration of a disease caused by a phytopathogenic fungus by contacting said fungus with a fungicidally effective amount of a formula I, 2,2-diaryl-1-(oxa or thia)-2a-azonia-2-borataacenaphthene compound. 
     The present invention also provides a method for the protection of a plant, plant seed or tuber from fungal infestation and disease by applying to the plant, plant seed or tuber, or to the medium or water in which it is growing, a fungicidally effective amount of a formula I, 2,2-diaryl-1-(oxa or thia)-2a-azonia-2-borataacenaphthene compound. 
     The fungicidal 2,2-diaryl-1-(oxa and thia)-2a-azonia-2-borataacenaphthene compounds of the present invention have the following structural formula I: ##STR3## wherein X and Y are each independently hydrogen, halogen, C 1  -C 6  alkoxy, C 1  -C 6  haloalkoxy, C 1  -C 6  alkyl or C 1  -C 6  haloalkyl; 
     m and n are each independently an integer of 0, 1, 2 or 3; 
     A is O or S; 
     R, R 1 , R 2 , R 3 , R 4  and R 5  are each independently hydrogen, halogen, C 1  -C 4  alkoxy, C 1  -C 4  haloalkoxy, C 1  -C 4  alkyl, C 1  -C 4  haloalkyl, C 1  -C 4  hydroxyalkyl, cyano, nitro, CH 2  CN, hydroxy, NR b  6 R 7 , SO 3  R 8  or COR 9  ; 
     R 6 , R 7  and R 8  are each independently hydrogen or C 1  -C 4  alkyl; and 
     R 9  is C 1  -C 4  alkyl. 
     Preferred formula I fungicidal agents of the present invention are those wherein 
     X and Y are each independently hydrogen, halogen or C 1  -C 6  alkyl; 
     m and n are each independently an integer of 0, 1 or 2; 
     A is O; 
     R, R 1 , R 2 , R 3 , R 4  and R 5  are each independently hydrogen, halogen, C 1  -C 4  alkyl, C 1  -C 4  hydroxyalkyl, nitro, CH 2  CN, NR 6  R 7  or SO 3  R 8  ; and 
     R 6 , R 7  and R 8  are each independently hydrogen or C 1  -C 4  alkyl. 
     Formula I 2,2-diaryl-1-oxa-2a-azonia-2-borataacenaphthene compounds which are particularly effective as fungicidal agents include 
     2,2-diphenyl-1-oxa-2a-azonia-2-borataacenaphthene; 
     2,2-di-p-tolyl-1-oxa-2a-azonia-2-borataacenaphthene; 
     2,2-bis(p-fluorophenyl)-1-oxa-2a-azonia-2-borataacenaphthene; 
     2,2-bis(p-tert-butylphenyl)-1-oxa-2a-azonia-2-borataacenaphthene; 
     3-methyl-2,2-diphenyl-1-oxa-2a-azonia-2-borataacenaphthene; 
     6-nitro-2,2-diphenyl-1-oxa-2a-azonia-2-borataacenaphthene; 
     7,9-dibromo-2,2-diphenyl-1-oxa-2a-azonia-2-borataacenaphthene; 
     6-chloro-2,2-di-p-tolyl-1-oxa-2a-azonia-2-borataacenaphthene; and 
     6,8-dichloro-2,2-di-p-tolyl-1-oxa-2a-azonia-2-borataacenaphthene, among others. 
     The term halogen used herein includes fluorine, chlorine, bromine and iodine. And the term &#34;medium&#34; used herein is defined as any environment, including but not limited to artificial nutrients or soil, in which a plant can be kept, live or thrive. 
     The fungicidal 2,2-diaryl-1-(oxa and thia)-2a-azonia-2-borataacenaphthene compounds of the present invention are particularly useful in the prevention, control or amelioration of diseases such as sugar beet cercospora leaf spot, apple scab, tomato early blight and grape or pepper botrytis. Such diseases are caused by the phytopathogenic fungi Cercospora beticola, Venturia inaequalis, Alternaria solani and Botrytis cinerea, respectively. 
     Fungicidal 2,2-diaryl-1-(oxa and thia)-2a-azonia-2-borataacenaphthene compounds of formula I may be prepared by reacting a substituted quinoline of formula II with a diarylborinic acid of formula III as shown in Flow Diagram I. ##STR4## 
     The formula I compounds are useful for controlling or preventing the growth of phytopathogenic fungi such as Cercospora beticola, Venturia inaequalis, Alternaria solani and Botrytis cinerea. Therefore, harmful diseases such as sugar beet cercospora leaf spot, apple scab, tomato early blight and grape and pepper botrytis may be prevented or controlled. 
     The formula I compounds are also useful for the protection of growing or harvested plants from the damage caused by phytopathogenic fungal disease when applied to said plants at a fungicidally effective rate. The effective rate will vary depending upon factors such as the virulence of the target fungus, the environment of the treatment and other ambient conditions. In practice, generally about 20 ppm to about 1,000 ppm, preferably about 50 ppm to about 500 ppm of the formula I compound may be dispersed in a liquid or solid carrier and applied to the plant, seed or tuber, or to the medium or water in which the plant, seed or tuber is growing. 
     The fungicidal compounds of the invention may be formulated as concentrated solutions, emulsifiable concentrates, flowable concentrates, microemulsions and the like. Said compounds may also be formulated as dry compacted granules, granular compositions, dusts, dust concentrates, suspension concentrates, wettable powders, and the like. Those formulations which lend themselves to seed, tuber, medium, water and/or foliage applications to provide the requisite plant protection are suitable. Such formulations include the compounds of the invention admixed with an inert solid or liquid carrier. 
     It is contemplated that the fungicidal compounds of the invention may be used in conjunction with, or in combination with, a pesticidally effective amount of one or more other pesticides, including but not limited to, anilazine, benalaxyl, benomyl, bitertanol, bordeaux mixture, carbendazim, carboxin, captafol, captan, chlorothalonil, cyproconazole, dichloran, diethofencarb, diniconazole, dithianon, dodine, edifenphos, fenarimol, fenbuconazole, fenfuram, fenpropidin, fenpropimorph, fentin hydroxide, ferbam, flusilazole, flusulfamide, flutriafol, folpet, fosetyl, fuberidazole, guazatine, hexaconazole, imazalil, iprobenfos, iprodione, mancozeb, maneb, metalaxyl, metiram, myclobutanil, nuarimol, ofurace, oxadixyl, oxycarboxin, penconazole, probenazole, prochloraz, propiconazole, pyrazophos, tebuconazole, thiabendazole, thiophanate, thiophanate-methyl, triadimefon, triadimenol, triarimol, tricyclazole, tridemorph, triflumizole, triforine, vinclozolin, zineb, and the like. 
     Where compositions of the invention are to be employed in combination treatments with other pesticidal agents, the composition may be applied concurrently as an admixture of the components as described above, or may be applied sequentially. 
     In order to facilitate a further understanding of the invention, the following examples are presented primarily for the purpose of illustrating more specific details thereof. The invention should not be deemed limited thereby except as defined in the claims. 
    
    
     EXAMPLE 1 
     Preparation of 2,2-Di-p-tolyl-1-oxa-2a-azonia-2-borataacenaphthene ##STR5## 
     A solution of [(bis-p-methyl)diphenyl]borinic acid (1.0 g, 4.7 mmol) in diethyl ether is added to a solution of 8-hydroxyquinoline (0.69 g, 4.7 mmol) in diethyl ether. The reaction mixture is stirred at room temperature for 30 minutes and filtered to obtain the title product as a yellow powder (1.1 g, mp 194°-195° C.). 
     Using essentially the same procedure, and employing the appropriately substituted diphenylborinic acid and 8-hydroxyquinoline, the following compounds are obtained: 
     
         __________________________________________________________________________ ##STR6##X     Y    R  R.sub.1               R.sub.3                    R.sub.5                           mp°C.__________________________________________________________________________CH.sub.3 CH.sub.3      H  H     Cl   Cl     220-223CH.sub.3 CH.sub.3      CH.sub.3         H     H    H      213-216CH.sub.3 CH.sub.3      H  H     Cl   H       99-102CH.sub.3 CH.sub.3      H  H     Br   Br     188-190CH.sub.3 CH.sub.3      H  H     NO.sub.2                    H      153-155C(CH.sub.3).sub.3 C(CH.sub.3).sub.3      H  H     Cl   Cl     230-232C(CH.sub.3).sub.3 C(CH.sub.3).sub.3      H  H     Cl   H      268-270C(CH.sub.3).sub.3 C(CH.sub.3).sub.3      H  H     NO.sub.2                    H      235-237C(CH.sub.3).sub.3 C(CH.sub.3).sub.3      H  H     H    H      232- 234C(CH.sub.3).sub.3 C(CH.sub.3).sub.3      CH.sub.3         H     H    H      201-203F     F    H  H     Cl   H       95-97F     F    H  H     CH.sub.2 CN                    H      120-121F     F    H  H     Cl   Br     178-180F     F    H  H     NO.sub.2                    H      137-139F     F    H  H     Cl   Cl     152-154F     F    CH.sub.3         H     H    H      139-142F     F    H  H     H    H       99-101H     H    H  H     SO.sub.3 H                    I      249-250H     H    H  H     NH.sub.2                    H        215-215.5H     H    H  H     H    (CH.sub.2).sub.2 CH.sub.3                             158-158.5H     H    H  H     I    I      287-288H     H    H  H     Cl   H      194.1-195H     H    H  H     Cl   Cl     268.5-270H     H    H  CH.sub.2 CH.sub.3               H    H      168-170H     H    H  H     Cl   Br     269-271H     H    H  H     H    Br     204-205H     H    H  H     NO.sub.2                    H      180-182H     H    H  H     Br   Br     &gt;270H     H    H  H     H    H      201-202H     H    CH.sub.3         H     H    H       176__________________________________________________________________________ 
    
     EXAMPLE 2 
     Evaluation of In Vivo Fungicidal Activity of Test Compounds 
     Test compounds are dissolved or suspended in acetone and diluted with deionized water containing about 0.05% TWEEN 20, a polyoxyethylene sorbitan monolaurate surfactant manufactured by Atlas Chemical Industries, to give a concentration of 200 ppm. 
     Host plants are sprayed with the test solution, dried and inoculated with fungi. When disease symptom development is optimal, the plants are rated for disease control according to the rating scale shown below. Each test contains inoculated treated plants, inoculated untreated plants and a reference standard. When more than one test is run, the data are averaged. The data obtained are shown in Table I. 
     Compounds employed in this in vivo fungicidal evaluation and in the in vitro fungicidal evaluation in the following example are given a compound number and identified by name. Data in Table I are reported by compound number. 
     
         ______________________________________RATING SCALERating      Range % Control______________________________________0           01            1-142           15-293           30-444           45-595           60-746           75-897           90-958           96-999           100--          no evaluation______________________________________PHYTOPATHOGENIC FUNGISymbol  Disease           Pathogen______________________________________AS      Apple Scab        Venturia inaequalisGDM     Grape Downy Mildew                     Plasmopara viticolaPB      Pepper Botrytis   Botrytis cinereaRB      Rice Blast        Pyricularia oryzaeSBC     Sugar Beet Cercospora                     Cercospora beticolaTEB     Tomato Early Blight                     Alternaria solaniWLR     Wheat Leaf Rust   Puccinia recondita                     f. sp. triticiWPM     Wheat Powdery Mildew                     Erysiphe graminis                     f. sp. triticiWSN     Wheat Septoria Nodorum                     Septoria nodorum   Blotch______________________________________COMPOUNDS EVALUATED AS FUNGICIDAL AGENTSCompoundNo.______________________________________ 1         3-Methyl-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene 2         2,2-Diphenyl-1-oxa-2a-azonia-2-borata-      acenaphthene 3         6-Nitro-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene 4         7,9-Dibromo-2,2-diphenyl-1-oxa-2a-azonia-      2-borataacenaphthene 5         2,2-Di-p-tolyl-1-oxa-2a-azonia-2-bora-      taacenaphthene 6         3-Methyl-2,2-di-p-tolyl-1-oxa-2a-azonia-      2-borataacenaphthene 7         6-Chloro-2,2-di-p-tolyl-1-oxa-2a-azonia-      2-borataacenaphthene 8         6,8-Dichloro-2,2-di-p-tolyl-1-oxa-2a-      azonia-2-borataacenaphthene 9         6-Nitro-2,2-di-p-tolyl-1-oxa-2a-azonia-      2-borataacenaphthene10         6,8-Dibromo-2,2-di-p-tolyl-1-oxa-2a-      azonia-2-borataacenaphthen11         2,2-Bis-(p-fluorophenyl)-1-oxa-2a-azonia-      2-borataacenaphthene12         2,2-Bis(p-fluorophenyl)-3-methyl-1-oxa-      2a-azonia-2-borataacenaphthene13         6-Chloro-2,2-bis(p-fluorophenyl)-1-oxa-      2a-azonia-2-borataacenaphthene14         6,8-Dichloro-2,2-bis(p-fluorophenyl)-1-      oxa-2a-azonia-2-borataacenaphthene15         2,2-Bis(p-fluorophenyl)-6-nitro-1-oxa-      2a-azonia-2-borataacenaphthene16         6-Chloro-2,2-diphenyl-1-oxa-2a-azonia-      2-borataacenaphthene17         6,8-Dichloro-2,2-diphenyl-1-oxa-2a-      azonia-2-borataacenaphthene18         2,2-bis(p-tert-butylphenyl)-1-oxa-2a-      azonia-2-borataacenaphthene19         2,2-Bis(p-tert-butylphenyl)-3-methyl-      1-oxa-2a-azonia-2-borataacenaphthene20         2,2-Bis(p-tert-butylphenyl)-6-chloro-      1-oxa-2a-azonia-2-borataacenaphthene21         2,2-Bis(p-tert-butylphenyl)-6-nitro-1-      oxa-2a-azonia-2-borataacenaphthene22         2,2-Bis(p-tert-butylphenyl)-6,8-dichloro-      1-oxa-2a-azonia-2-borataacenaphthene23         4-Ethyl-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene24         8-Bromo-6-chloro-2,2-diphenyl-1-oxa-2a-      azonia-2-borataacenaphthene25         8-Bromo-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene26         8-Bromo-6-chloro-2,2-bis(p-fluorophenyl)-      1-oxa-2a-azonia-2-borataacenaphthene27         6-Amino-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene28         6,8-Diiodo-2,2-diphenyl-1-oxa-2a-azonia-      2-borataacenaphthene29         8-Iodo-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene-6-sulfonic acid30         2,2-Bis(p-fluorophenyl)-1-oxa-2a-azonia-      2-borataacenaphthene-7-aceonitrile31         8-Propyl-2,2-diphenyl-1-oxa-2a-azonia-2-      borataacenaphthene______________________________________ 
    
     
                                           TABLE I__________________________________________________________________________In Vivo Fungicidal EvaluationsCompound RateNumber (ppm)     AS GDM PB              RB SBC                    TEB                       WLR WPM WSN__________________________________________________________________________ 1    200 9  8   9 0  0  4  7   0   -- 2    200 9  9   9 9  8  8  9   0   -- 3    200 6  0   8 0  8  4  0   8   -- 4    200 0  5   0 0  0  0  0   0   -- 5    200 9  9   9 0  7  9  0   0   -- 6    200 6  7   6 0  0  6  0   0   -- 7    200 7  0   9 0  0  4  0   0   -- 8    200 6  7   0 0  0  0  0   0   -- 9    200 6  0   6 0  6  4  8   4   --10    200 0  0   0 0  0  0  0   0   --11    200 9  9   9 8  8  9  9   0   --12    200 9  7   7 8  6  8  9   6   --13    200 9  9   7 6  0  9  8   6   --14    200 9  6   6 6  0  6  8   7   --15    200 9  5   0 6  0  8  8   0   --16    200 8  0   9 6  8  8  0   0   --17    200 6  0   0 0  5  4  0   0   --18    200 8  9   9 6  8  4  --  0   819    200 8  6   0 4  0  0  --  0   220    200 7  0   9 0  7  0  --  0   021    200 8  0   0 0  8  0  --  4   022    200 7  0   0 0  7  2  --  4   023    200 8  7   9 6  8  9  --  0   024    200 0  0   0 0  7  0  --  0   025    200 8  9   9 4  8  9  --  0   726    200 0  5   0 4  4  0  --  6   027    200 4  3   2 0  0  0  --  0   028    200 0  0   0 0  0  0  --  0   029    200 0  0   7 0  0  0  --  0   030    200 8  6   8 8  5  0  --  7   531    200 7  4   7 0  7  4  --  0   0__________________________________________________________________________ 
    
     EXAMPLE 3 
     Evaluation of In Vitro Fungicidal Activity of Test Compounds 
     Test compounds are dissolved or suspended in acetone and dispersed into cell well plates containing a suspension of ground fungal mycelia in a nutrient broth. Assay plates are incubated for 3-4 days at 21° C. Growth inhibition is measured visually and is rated using the following scale: 
     
         ______________________________________  Rating        % Inhibition______________________________________  0     0  1      1-29  3     30-59  5     60-89  7     90-99  9     100______________________________________ 
    
     Untreated controls, solvent blanks and reference standards are included in each test. 
     Assay fungi include the plant pathogens, Pythium ultimum (Pythul); Rhizoctonia solani (Rhizso); Fusarium oxysporum f. sp. cucumerinum (Fusoxc); and Pseudocercosporella herpotrichoides (Psdche). 
     When more than one test is run, the data are averaged. The data obtained are shown in Table II. The compounds evaluated are reported by compound number given in Example 2. 
     
                                           TABLE II__________________________________________________________________________In Vitro Fungicidal EvaluationsCompound  RateNumber (ppm)       FUSOXC PSDCHE PYTHUL RHIZSO__________________________________________________________________________ 1     25   5      7      9      9 2     25   3      0      5      7 3     25   5      8      7      7 4     25   7      0      1      5 5     25   3      5      0      7 6     25   3      0      0      0 7     25   9      7      3      7 8     25   7      9      7      9 9     25   9      9      9      910     25   9      5      0      711     25   5      7      7      512     25   7      5      5      913     25   7      9      9      914     25   9      7      7      915     25   9      9      9      716     25   5      9      7      917     25   7      7      5      918     25   9      9      9      919     25   0      0      0      020     25   0      0      0      021     25   5      9      7      722     25   7      9      7      923     25   3      5      5      524     25   9      7      5      925     25   7      9      9      926     25   9      9      9      727     25   7      0      7      528     25   3      0      0      529     25   9      7      7      530     25   5      0      7      731     25   1      0      3      3__________________________________________________________________________