Use of pyrazole propargyl ethers as nitrification inhibitors

Abstract

The present invention relates to novel nitrification inhibitors of formula (I), which are pyrazole propargyl ether compounds. Moreover, the invention relates to the use of compounds of formula (I) as nitrification inhibitors, i.e. for reducing nitrification, as well as agrochemical mixtures and compositions comprising the nitrification inhibitors of formula (I).

Claims

1. A method for reducing nitrification, comprising treating a plant growing on soil or soil substituents and/or the locus or soil or soil substituents where the plant is growing or is intended to grow with at least one compound of formula I: ##STR00022## or a salt, stereoisomer, tautomer, or N-oxide thereof, wherein R.sup.2 is halogen, C.sub.1-C.sub.6-alkyl, C.sub.3-C.sub.6-cycloalkyl, allyl, propargyl, benzyl, or phenyl, wherein said phenyl group is unsubstituted or substituted by one or more, same or different substituents R.sup.x; R.sup.N is H, C.sub.1-C.sub.6-alkyl, C.sub.3-C.sub.6-cycloalkyl, benzyl, allyl, propargyl, or phenyl, wherein said groups are unsubstituted or substituted by one or more, same or different substituents R.sup.y; CHR.sup.aC(═O)OR.sup.b, CHR.sup.aC(═O)NR.sup.bR.sup.c, CH(C(═O)OR.sup.b)CH.sub.2(C(═O)OR.sup.b); C(═O)R.sup.d, C(═O)OR.sup.b, C(═O)NR.sup.bR.sup.c, CHR.sup.aOR.sup.b or CHR.sup.aNR.sup.e(C═O)R.sup.f; and wherein R.sup.a is H, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.3-C.sub.8-cycloalkyl, phenyl, or phenyl-C.sub.1-C.sub.2-alkyl; R.sup.b is H, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.3-C.sub.8-cycloalkyl, phenyl, or phenyl-C.sub.1-C.sub.2-alkyl; R.sup.c is H, C.sub.1-C.sub.6-alkyl, C.sub.1-C.sub.4-haloalkyl, or phenyl; R.sup.d is H, C.sub.1-C.sub.8-alkyl, C.sub.2-C.sub.8-alkenyl, C.sub.2-C.sub.8-alkynyl, phenyl, or phenyl-C.sub.1-C.sub.2-alkyl, wherein these groups are unsubstituted or substituted by a group COOH; R.sup.e is H, C.sub.1-C.sub.4-alkyl, C.sub.3-C.sub.8-cycloalkyl, or C.sub.6-C.sub.10-aryl; R.sup.f is H, or C.sub.1-C.sub.4-alkyl; R.sup.x is halogen, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.1-C.sub.4-alkoxy, or C.sub.1-C.sub.4-haloalkoxy; R.sup.y is halogen, CN, OH, NO.sub.2, COOH, NR.sup.bR.sup.c, NR.sup.b(C═O)R.sup.f, C(═O)NR.sup.bR.sup.c, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.1-C.sub.4-alkoxy, C.sub.1-C.sub.4-haloalkoxy, C.sub.1-C.sub.4-alkylcarbonyl, C.sub.1-C.sub.4-alkylcarboxy, C.sub.1-C.sub.4-alkylthio, C.sub.1-C.sub.4-alkylsulfonyl, and S(O).sub.2NR.sup.bR.sup.c; n is 0, 1, or 2.

2. The method of claim 1, wherein the plant and/or the locus or soil or soil substituents where the plant is growing or is intended to grow is additionally provided with a fertilizer.

3. The method of claim 2, wherein the application of said compound of formula I and of said fertilizer is carried out simultaneously or with a time lag.

4. The method of claim 3 wherein the time lag is an interval of 1 day, 2 days, 3 days, 1 week, 2 weeks, or 3 weeks.

5. The method of claim 1, wherein the compound of formula I is present in the form of a pyrazolium salt.

6. The method of claim 5 wherein the pyrazolium salt is a pyrazolium phosphate salt.

7. The method of claim 1, wherein said plant is an agricultural plant; or a vegetable; sorghum; a silvicultural plant; an ornamental plant; or a horticultural plant, each in its natural or in a genetically modified form.

8. The method of claim 7 wherein the agricultural plant or vegetable is selected from the group consisting of wheat, barley, oat, rye, soybean, corn, potatoes, oilseed rape, canola, sunflower, cotton, sugar cane, sugar beet, rice, spinach, lettuce, asparagus, and cabbages.

9. The method of claim 1, wherein n is 0; or n is 1, and R.sup.2 is C.sub.1-C.sub.3-alkyl or phenyl.

10. The method of claim 1, wherein R.sup.N is H.

11. The method of claim 1, wherein R.sup.N is C(═O)R.sup.d, CHR.sup.aC(═O)OR.sup.b, CHR.sup.aC(═O)NR.sup.bR.sup.c, CH(C(═O)OR.sup.b)CH.sub.2(C(═O)OR.sup.b) or CHR.sup.aNR.sup.e(C═O)R.sup.f.

12. A method for treating a fertilizer comprising applying a nitrification inhibitor of formula I to the fertilizer: ##STR00023## or a salt, stereoisomer, tautomer, or N-oxide thereof, wherein R.sup.2 is halogen, C.sub.1-C.sub.6-alkyl, C.sub.3-C.sub.6-cycloalkyl, allyl, propargyl, benzyl, or phenyl, wherein said phenyl group is unsubstituted or substituted by one or more, same or different substituents R.sup.x; R.sup.N is H, C.sub.1-C.sub.6-alkyl, C.sub.3-C.sub.6-cycloalkyl, benzyl, allyl, propargyl, or phenyl, wherein said groups are unsubstituted or substituted by one or more, same or different substituents R.sup.y; CHR.sup.aC(═O)OR.sup.b, CHR.sup.aC(═O)NR.sup.bR.sup.c, CH(C(═O)OR.sup.b)CH.sub.2(C(═O)OR.sup.b); C(═O)R.sup.d, C(═O)OR.sup.b, C(═O)NR.sup.bR.sup.c, CHR.sup.aOR.sup.b or CHR.sup.aNR.sup.e(C═O)R.sup.f; and wherein R.sup.a is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.3-C.sub.8-cycloalkyl, phenyl, or phenyl-C.sub.1-C.sub.2-alkyl; R.sup.b is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.3-C.sub.8-cycloalkyl, phenyl, or phenyl-C.sub.1-C.sub.2-alkyl; R.sup.c is H, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, or phenyl; R.sup.d is H, C.sub.1-C8-alkyl, C.sub.2-C.sub.8-alkenyl, C.sub.2-C.sub.8-alkynyl, phenyl, or phenyl-C1-C.sub.2-alkyl, wherein these groups are unsubstituted or substituted by a group COOH; R.sup.e is H, C.sub.1-C.sub.4-alkyl, C.sub.3-C.sub.8-cycloalkyl, or C.sub.6-C.sub.10-aryl; R.sup.f is H, or C.sub.1-C4-alkyl; R.sup.x is halogen, C.sub.1-C4-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.1-C.sub.4-alkoxy, or C1-C.sub.4-haloalkoxy; R.sup.y is halogen, CN, OH, NO.sub.2, COOH, NR.sup.bR.sup.c, NR.sup.b(C═O)R.sup.f, C(═O)NR.sup.bR.sup.c, C.sub.1-C.sub.4-alkyl, C.sub.1-C.sub.4-haloalkyl, C.sub.1-C.sub.4-alkoxy, C.sub.1-C.sub.4-haloalkoxy, C1-C.sub.4-alkylcarbonyl, C.sub.1-C.sub.4-alkylcarboxy, C.sub.1-C.sub.4-alkylthio, C.sub.1-C.sub.4-alkylsulfonyl, and S(O).sub.2NR.sup.bR.sup.c; n is 0, 1, or 2.

Description

EXAMPLES

Example 1

(1) The compounds of the invention have been tested as follows in terms of the inhibition of nitrification:

(2) 100 g soil is filled into 500 ml plastic bottles (e.g. soil sampled from the field) and is moistened to 50% water holding capacity. The soil is incubated at 20° C. for two weeks to activate the microbial biomass. 1 ml test solution, containing the compound in the appropriate concentration (usually 0.3 or 1% of nitrogen N), or DMSO and 10 mg nitrogen in the form of ammoniumsulfate-N is added to the soil and everything mixed well. Bottles are capped but loosely to allow air exchange. The bottles are then incubated at 20° C. for 0 and 14 days.

(3) For analysis, 300 ml of a 1% K.sub.2SO.sub.4-solution is added to the bottle containing the soil and shaken for 2 hours in a horizontal shaker at 150 rpm. Then the whole solution is filtered through a filter (Macherey-Nagel Filter MN 807¼). Ammonium and nitrate content is then analyzed in the filtrate in an autoanalyzer at 550 nm (Merck, AA11).

(4) The inhibition (NI @ a specified concentration) is calculated as follows:

(5) $\mathrm{inhibition}\mathrm{in}\%=\frac{\left(\begin{array}{c}\mathrm{NO}3-N_{\mathrm{without}\mathrm{NI}\mathrm{at}\mathrm{end}\mathrm{of}\mathrm{incubation}}-\\ \mathrm{NO}3-N_{\mathrm{with}\mathrm{NI}\mathrm{at}\mathrm{end}\mathrm{of}\mathrm{incubation}}\end{array}\right)}{\left(\mathrm{NO}3-N_{\mathrm{without}\mathrm{NI}\mathrm{at}\mathrm{end}\mathrm{of}\mathrm{incubation}}-\mathrm{NO}3-N_{\mathrm{at}\mathrm{beginning}}\right)}\times 100$

(6) The following compounds of general formula I.3(i) have been tested. As described above, the compounds of general formula I.3(i) are present in the form of the two possible annular tautomers, if R.sup.N is H.

(7) TABLE-US-00013 I.3(i) No. R.sup.N NI* @ 1% NI* @ 0.3% 1 H 74.7 60.6 *In each case the best obtained NI value is provided (only compounds with values >20).
Further, the following compounds of general formula I.1(i) have been tested.

(8) TABLE-US-00014 I.1(i) 0 No. R.sup.N NI* @ 1% NI* @ 0.3% 2 C(═O)CH.sub.3 72.5 53.9 *In each case the best obtained NI value is provided (only compounds with values > 20).
Further, the following compounds of general formula I.1(iii) have been tested.

(9) TABLE-US-00015 I.1(iii) No. R.sup.N R.sup.2 NI* @ 1% NI* @ 0.3% 3 C(═O)CH.sub.3 CH.sub.3 47.3 34.4 *In each case the best obtained NI value is provided (only compounds with values > 20).