CS196411B2 - Cereals growth regulator - Google Patents

Abstract

The plant growth regulators contain from 1 to 99 % by weight of an active substance of the formula: <IMAGE> or an alkali metal salt, amine salt or ammonium salt thereof. In the formula I, R, R1 and R2 have the meanings given in Patent Claim 1. To alter the development of the reproductive components of a maize plant, an effective and non-lethal amount of an active substance of the formula I is applied to the maize plant.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to cereal growth regulators containing the novel phthalamic acid or nicotinic acid of the formula I as active ingredient

wherein R represents a hydrogen atom or a C _1-4 alkyl group,

R ( ¹⁾ is carbon or nitrogen,

R ^{2 is a} pyridyl or substituted pyridyl group or, when R ¹ represents a nitrogen atom, R ² represents a pyridyl, substituted phenyl group, or an agriculturally acceptable salt thereof.

The term "substituted pyridyl" in the description of the invention refers to radicals of the general formulas

wherein X and Y are independently selected from the group consisting of hydrogen or halogen, CF 3, C _1-4 alkyl, and C 1-4 alkoxy, provided that neither X nor Y is a 4-position chlorine atom; 11 atom of the nitrogen in position 3.

The term "substituted phenyl" in the description of the invention refers to radicals of the general formula.

- <□ /

198411 in which

X and Y are as defined above.

The term &quot; agriculturally acceptable salts &quot; refers to alkali metal salts, substituted amine salts such as isopropyl-pylamine ... or triethylamine, and ammonium salts. of , .

The phthalamic acid of formula (I) in which R @ ¹ is a carbon atom can be prepared by adding a stoichiometric equivalent of the corresponding aminopyridine to a suspension of phthalic anhydride in chloroform, stirring at room temperature and separating the precipitated product. filtered and air dried. The preparation of the new phthalamic acids is illustrated in more detail in the following examples.

Example. . . . ·

To a suspension of 0.1 mol of acid anhydride in one portion, 0.1 mol of 3-amino-2-chloropyridine and the reaction mixture was stirred for ~ 4 hours. The resulting N- (2-chloro-3-pyridyl) phthalamic acid is filtered off and air dried; melting point -03 ° C (yield 87 ·%).

Elementary analysis:

calculated:

12.81% · Cl, · 10.12% · N,. '.

found:. . .119.94% CI, 10.37% N. '.

In the same manner as in Example 1, phthalic acid was added in 100 ml of chloroform to prepare the following compounds:

Example Compound Analysis calculated / found 2 · ' N- (6-methoxy-3-pyridyl) - ^61, 80% C ^4, 44% fy ^10, 30% N · phthalamic 61.94% C, 4.42% H, 10.26% N 3 N- (5-bromo-2-pyridyl) acid ... 8.72% N, 24.88% Br. . Phthalmone 8.69 ·% N, 24.75. % Br '' '4 N- (4,6-dimethyl-2-pyridyl) - 66.65% C, -5.22% f 10.36% N % C, 66.53; H, 5.28; N, 10.35

The sodium salts of the new phthalamic acids can be prepared by mixing a mixture of 0.1 mol of the appropriate acid and 400 ml of water with a stoichiometric amount of 50% aqueous sodium hydroxide solution for one hour. The following salts are prepared as follows:

Example Compound Sodium salt of N- (5-chloro-2-pyridyl) phthalamic acid. sodium salt of N- (2- ·· '

(chloro-3-pyridyl) phthalamide.

The ammonium salts of the above acids and their substituted amine salts can be prepared by the method of the following examples. . 'Example · <7. · Ý

To a suspension of 0.1 mol of N- (2-chloro-3-pyridyl) phthalamic acid in 500 ml of ethyl ether is added, in one portion, 0.11 mol of isopropylamine. The mixture is stirred for 24 hours at 25 to 30 ° C, then the precipitated isopropylammonium acid salt is formed. filtered and air dried; yield 100%, mp 147-418 ° C.

Elementary analysis:

calculated:.

57.23% C, 5.40% H, 10.56% Cl,

12.61 ·% N, found: .............

% C, 57.68;% H, 5.45; 12.59.% N.

• Example

Following the procedure described in Example 6, N- (5-bromo-2-pyridyl) phthalamic acid isopropylammonium salt was prepared; 145 DEG -146 DEG C. Yield 87%. -Elementary analysis:

calculated:

C, 50.54; 4.77. % H, 11.05 '% N, found:

% C, 50.42;% H, 4.73;% N, 10.99%.

New · · nicotinic acids of formula I wherein R ¹ is a nitrogen atom, can be prepared in such a way • that to a suspension of 0.1 mol of anhydride .2,3-pyridine in 100 ml of chloroform was added 0.1 mol · of the respective substituted aniline or aminochloropyridine and the reaction mixture is stirred at 25-30 ° C for 24 hours. The precipitated product is filtered off and air-dried at 25-30 ° C. In this way, the compounds shown in Examples 9-16 and summarized in Table I below were prepared.

Table I

N 00 Ml CD Г ^ ιη ОС σΓ

со СО 00 гЧ г- ^ о Ю ас σΓ

гЧ

lie. см Ю 00 СП о см со 00 on со СМ * см * см *

'·. '5

According to the invention, the esters of the novel phthalamic and / or rucoic acids can be prepared as follows.

.example ⁷ '

To a suspension of 27.7 g (0.1 mol) of N- (2-chloro-3-pyridyl) phthalamic acid in 300 ml of methyl alcohol, 71 g (0.5 mol) of fluoride etherate are added in one portion with stirring. An exothermic reaction occurs and the temperature of the reaction mixture rises from 21 ° C to 33 ° C. · The reaction mixture is heated to reflux under stirring for 24 hours, then cooled to -10 °. 1000 ml of a 10% aqueous solution of sodium bicarbonate is slowly added thereto at -10 DEG C. to 0 DEG C. The mixture is stirred for 30 minutes at 0 DEG to 10 DEG C., then the precipitated product is filtered off, washed with water. at 25-30 ° C to give crude N- (2-chloro-3-pyridyl) phthalamic acid methyl ester of mp 110-112 ° C in a yield of 76% · After two crystallizations · from a mixture of heptane and isopropyl alcohol, pure methyl ether of melting point 122 to 124 ° C is obtained.

Elementary · Analysis:

For C 14 H 11 ClN 2 O 3 calculated:.

% C, 57.81;% C, 12.20;

9.64 ·% N, found:

57.88% C 3.57% H, 12.45% · Cl,

9.41% N.

The inventors have found that the compounds of formula I cause changes in the development of the reproductive organs of maize plants, both male (panicles, corn tassels) and female (corn cobs).

The term “changes in the development of organ reproduction” of maize plants means modifications of the normal gradual development of these organs until adulthood. Said modifications are most readily observed as inhibition of growth of corn strips, inhibition of growth of lateral corn strips, changes in number, shape and position of the sticks, changes in grain number and ripening rate. ·· grains and the like.

According to the inventors, changes in the development of reproductive organs of healthy maize plants can be achieved by applying to said maize plants an effective, non-lethal amount of acids of the formula I even before or during the early stages of development of said reproductive organs. in the stage of differentiation of these organs. The application of these substances results in a reduction, size or elimination of corn strips, which will allow hybrid corn plant growers to reduce or eliminate the work required to manually remove said corn strips. In addition, due to the application of an effective amount of the active ingredient before or during the early stages of corn cob development, the grain yield per unit area of the field can be increased.

. The term &quot; active ingredient &quot; as used herein refers to the acids of formula (I).

The efficacy of compounds 1-16 described above was determined as follows.

Example A.

Corn plants of the species A-619 'were grown and unified to obtain a uniform culture. All weak or developmentally delayed plants were removed before chemical treatment. The spray solution was prepared by dissolving 50 mg or 100 mg of the active ingredient in a mixture of 7.5 ml of acetone with 7.5 ml of water and adding 0.25% of Tween 20 as a surface coating to the solution. active substances. Corn. early reproductive organ differentiation plants were sprayed with said solution with a Devillbiss 153 sprayer. at a dose of 10 mg per plant or 20 mg per plant.

The results were determined by comparing the treated plants with a control group of plants that were not chemically treated. It has been found that the test compounds of formula (I) cause changes in the development of the reproductive organs of maize plants, which are manifested by the fact that the formation of lateral maize slats is suppressed by at least 25% compared to control plants.

In the above manner, it has been found that compounds 1, 2, 5, 6 and 9-11 inhibit the development of lateral corn strips by 50% and 74%. Compounds 3, 7, 8 and 12-16 inhibit the development of stubborn male slats from 25% to 49%. The compounds further inhibit the development of male flowers as shown in Table II.

Table II

Compound cm flowers control224

167

3132

475

Example 1 a d B

In this test, N- (2-chloro-3-pyridyl) phthalamic acid was applied to the corn plants as a spray, prepared as described in Example A. It was found that the substance caused changes in the height of the corn sticks. increased maturation rate and induced partial sterility of male flowers. The results are summarized in Table III.

196411 7 ⁸ ' ⁴ Table III ./. г ”· d'en - 16 ^e) Treatment of plants in '. kg / hectare day 9 dose day - 12 and> Mallet height (cm) Sterility of male flowers • (v -.% -) ·. 0 0 . - - - - 0 48 . 0 1.12 1.12 0 '73 80 1.12 0 1.12 54 88 ' 1,12 - - 0.56 0 '57 75 1.12 0 - - · 0.56 52 89 • 0,56 · 1.12 . 0 60 · . 68 0.56 0 1.12 48  95 0.56 0.56 0 55 74  0.56 0 0.56  - 48 88

^a> Calculated since plant emergence ·

The above tests show that the most suitable time of application of the Halamic acids of formula I is before or during the early stages of differentiation of the reproductive organs of the maize plants. Ke. the differentiation of the reproductive organ occurs at different times, depending on the type of maize plants and various environmental factors. For example, differentiation of the male reproductive organs of maize Gaspe begins during the formation of the bud of the sticks, while differentiation of the reproductive organs of maize A-619 begins within the first 8-12 days after plant emergence. Experts easily - find out - when differentiation of reproductive organs occurs. By way of example, and for clarification only, most maize species grown in the mid-west of the United States need to be sprayed from 3 to 25 days after plant emergence. Species of wheat grape cultivated - in foreign countries require - treatment from 1 to - 40 days after emergence of plants, from the following. In the case of maize of the type A-619, the compounds of the formula I are applied - preferably at a time between 7 and 12 days after emergence - of the plants.

Example C

Maize - A-619 was grown on plots of 64,000 plants per - - one hectare. The plants were sprayed at doses ranging from 0.56 to 1.68 kg per hectare; the spray solution consisted of compound number 6, 50 acetone, 0.25% Tween 20 and the required amount of water to be applied at 320 liters per hectare. Some sprays - were applied in the early stages of development, before or on the twentieth day after the emergence of the plants. The other sprays were applied in later periods, after the twelfth day of leaving the plants. -After harvesting the plants, it was leveled. grain yield from treated plants with yield - grain from untreated control plants. The test results are given in Table IV,

Table IV

Control revenue

Yields in grams - Early application

Late application average

1300. ,, 2060. 1940 2940 1650 1540 1740 - -. 1700, . 1740 1720 1910 2170 1660 1810 2430 . 1390 1850 2230 1480 1770 1730 1130 1773 <2057 1476

. . In the practice of controlling plant growth, the active compounds can be used either. alone or in combination with liquid or solid excipients. In preparing plant growth regulating compositions, the active compound of formula (I) is admixed with a suitable excipient including diluents, fillers, carriers and conditioning agents, and the mixture is finely divided. sprayed solid dusts, granules, pellets, wettable dusts, solutions, aqueous dispersions or aqueous emulsions. Finely divided solids may be used as excipients for the active substance. organic solvent solvents, water wetting agents, dispersing agents or emulsifying agents, or any suitable combination thereof.

Talc, various types of clay, pumice, silica gel, diatomaceous earth, quartz, fuller's earth, sulfur, ground cork, wood flour, nut flour can be used as finely divided solid carriers and fillers for preparing the plant growth regulating compositions of the invention. shells, chalk, tobacco flour, pulverized coal and the like. Typical liquid diluents include. use of Stoddard solution, acetone, alcohols, glycols, ethylacetate, benzene and the like. The plant growth regulating compositions of the invention, in particular liquids and wettable dusts, usually contain one or more surfactants in an amount sufficient to render the composition readily dispersible in water or oil. The term "surfactant" includes wetting agents in this specification; dispersing agents and emulsifiers. Said surfactants are well known to those skilled in the art, and detailed examples of such surfactants are given, for example, in U.S. Patent 2,547,724, columns 3 and 4.

¹⁰

The active compounds are usually administered in the form of mixtures containing one or more excipients which, when applied, aid in the uniform distribution of the active ingredient. Liquid and finely divided solid compositions containing the active ingredient can be applied by conventional techniques, for example by means of sprinklers, sprayers, frame and hand sprayers and shredders. Plant growth regulating compositions can also be applied in the form of dusts or sprayings from aircraft.

The plant growth regulators of the invention usually contain about 1-99 parts by weight of active ingredient, about 1-50 parts by weight of surfactant and about 4-94 parts by weight of solvents, all parts by weight based on the total weight of the composition.

When choosing the appropriate application. It is to be understood that the exact dose also depends on the method of application, the plant species, the soil conditions and other factors well known to those skilled in the art. A preferred application rate is about 0.056 to 5.6 kg per hectare, but higher doses than 56 kg per hectare may be used depending on the above factors.

According to the invention, it is not envisaged to use said compositions in phytotoxic doses which have a herbicidal effect. Further, one or more applications of a plant growth regulator may be used to achieve the desired effect.

Although the invention has been described with respect to specific modifications thereof, these details are not to be construed as limiting thereof. It is to be understood that various changes and modifications may be made and equivalent procedures may be employed without departing from the spirit and scope of the invention, and all such equivalent modifications are included within the scope of the invention.

Claims (3)

OBJECT OF THE INVENTION. Crop growth regulator, characterized in that it contains from 1 to 99 parts by weight of phthalamic acid or nicotinic acid of the formula I as active substance, R 2 is a pyridyl group, an optionally substituted pyridyl group of the formulas wherein X and Y are independently selected from the group consisting of hydrogen or halogen, trifluoromethyl, C 1-4 alkyl and C 1-4 alkoxy, with the proviso that neither X nor Y may be a chlorine atom position 4, when the nitrogen atom is in the 3-position, or when R 1 is a nitrogen atom, R 2 represents a pyridyl group optionally substituted as mentioned above or a substituted phenyl group of the formula R is hydrogen or C 1-4 alkyl, R1 is a carbon or nitrogen atom in which X and Y are as defined above, or agriculturally acceptable salts thereof, the remaining parts by weight being mixtures. they comprise at least one suitable carrier, diluent and / or excipient. . 2., Cereal growth regulator according to. 1, characterized in that:. that like. the active substance contains an acid. N- (2-chloro-3-pyridyl) phthalamic acid. 3. Cereal growth regulator according to claim 1, characterized in that:. The composition according to claim 1, characterized in that it contains, as an active ingredient, the sodium salt of N- (2-chloro-3-pyridyl) phthalamic acid.