Certain 3-benzoyl-4-oxolactams

Abstract

Compounds having the formula ##STR1## wherein R is halogen; C.sub.1 -C.sub.2 alkyl; C.sub.1 -C.sub.2 alkoxy; nitro; cyano; C.sub.1 -C.sub.2 haloalkyl; or R.sup.a SO.sub.n --wherein n is 0 or 2 and R.sup.a is C.sub.1 -C.sub.2 alkyl; R.sup.1 is hydrogen or C.sub.1 -C.sub.4 alkyl; R.sup.2 is hydrogen or C.sub.1 -C.sub.4 alkyl; or R.sup.1 and R.sup.2 together are alkylene having 2-5 carbon atoms; R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl; R.sup.4 is hydrogen or C.sub.1 -C.sub.4 alkyl; or R.sup.3 and R.sup.4 together are carbonyl; and R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen; (3) C.sub.1 -C.sub.4 alkyl; (4) C.sub.1 -C.sub.4 alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C.sub.1 -C.sub.4 haloalkyl; (9) R.sup.b SO.sub.m --wherein m is the integer 0, 1 or 2; and R.sup.b is (a) C.sub.1 - C.sub.4 alkyl; (b) C.sub.1 -C.sub.4 alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.e C(O)--wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; or (12) --SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; and (13) --N(R.sup.c)C(O)R.sup.d wherein R.sup.c and R.sup.d are as defined; R.sup.7 is C.sub.1 -C.sub.4 alkyl or phenyl; and t is the integer 0 or 1 and their salts are useful as herbicides.

Description

BACKGROUND OF THE INVENTION

The compound having the structural formula ##STR2## wherein the nitro substituent is in the 3- or 4-position are described in J. Heterocyclic Chem., 6(1), pp. 13-22 (1969). No utility for these compounds is taught.

Compounds of the structural formula ##STR3## wherein X is halogen, CF.sub.3, alkyl, nitro, cyano or alkoxy are described in European patent application publication No. 40 082 (1981). The compounds are intermediates for the preparation of certain substituted oxonicotinates.

DESCRIPTION OF THE INVENTION

This invention relates to certain 3-benzoyl-4-oxolactams and their salts and their use as herbicides.

One embodiment of this invention is an herbicidal composition comprising an herbicidally active 3-benzoyl-4-oxolactam and an inert carrier therefor wherein the 2-position of the benzoyl moiety is substituted with halogen; C.sub.1 -C.sub.2 alkyl, preferably methyl; C.sub.1 -C.sub.2 alkoxy, preferably methoxy; nitro; cyano; C.sub.1 -C.sub.2 haloalkyl, preferably trifluoromethyl or R.sup.a SO.sub.n -- wherein R.sup.a is C.sub.1 -C.sub.2 alkyl, preferably methyl and n is the integer 0 or 2, preferably 2; and the 4-position preferably is substituted with an electron withdrawing group, such as halogen, cyano or trifluoromethyl. The 5- or 6-positions of the 4-oxolactam moiety can be substituted, preferably with the groups hereinafter recited. The 1-position of the 4-oxolactam moiety is preferably substituted with C.sub.1 -C.sub.4 alkyl. The 3-, 4-, 5- and 6-positions of the benzoyl moiety can be substituted, preferably with the groups hereinafter recited.

Also embodied within the scope of this invention are novel compounds having the following structural formula ##STR4## wherein R is halogen, C.sub.1 -C.sub.2 alkyl, preferably methyl; C.sub.1 -C.sub.2 alkoxy, preferably methoxy; nitro; cyano; C.sub.1 -C.sub.2 haloalkyl, preferably trifluoromethyl; or R.sup.a SO.sub.n -- wherein R.sup.a is C.sub.1 -C.sub.2 alkyl, preferably methyl and n is the integer 0 or 2, preferably 2;

R.sup.1 is hydrogen or C.sub.1 -C.sub.4 alkyl, preferably C.sub.1 -C.sub.2 alkyl, more preferably methyl, most preferably R.sup.1 is hydrogen or methyl; R.sup.2 is hydrogen; C.sub.1 -C.sub.4 alkyl, preferably C.sub.1 -C.sub.2 alkyl, more preferably methyl most preferably R.sup.2 is hydrogen or methyl; or R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl, preferably C.sub.1 -C.sub.2 alkyl, more preferably methyl; most preferably R.sup.3 is hydrogen or methyl; R.sup.4 is hydrogen or C.sub.1 -C.sub.4 alkyl, preferably C.sub.1 -C.sub.2 alkyl, more preferably methyl; most preferably R.sup.4 is hydrogen or methyl; or R.sup.3 and R.sup.4 together are carbonyl; or R.sup.1 and R.sup.2 together are alkylene having 2-5 carbon atoms; or R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen, preferably chlorine, fluorine or bromine; (3) C.sub.1 -C.sub.4 alkyl, preferably methyl; (4) C.sub.1 -C.sub.4 alkoxy, preferably methoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C.sub.1 -C.sub.4 haloalkyl, more preferably trifluoromethyl; (9) R.sup.b SO.sub.m -- wherein m is the integer 0, 1 or 2, preferably 2; and R.sup.b is (a) C.sub.1 -C.sub.4 alkyl, preferably methyl; (b) C.sub.1 -C.sub.4 alkyl substituted with halogen or cyano, preferably chloromethyl, trifluoromethyl or cyanomethyl; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.e C(O)-- wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; (12) --SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; and (13) --N(R.sup.C)C(O)R.sup.d wherein R.sup.c and R.sup.d are as defined; R.sup.7 is C.sub.1 -C.sub.4 alkyl, preferably C.sub.1 -C.sub.2 alkyl or phenyl; and t is the integer 0 or 1, preferably 1.

The term "C.sub.1 -C.sub.4 alkyl" includes methyl, ethyl, n-propyl, isopropyl n-butyl, sec-butyl, isobutyl and t-butyl. The term "halogen" includes chlorine, bromine, iodine and fluorine. The term "C.sub.1 -C.sub.4 alkoxy" includes methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy and t-butoxy. The term "C.sub.1 -C.sub.4 haloalkyl" includes the alkyl groups defined above under C.sub.1 -C.sub.4 alkyl in which one or more hydrogens is replaced by chloro, bromo, iodo or fluoro.

Preferably, R.sup.5 is in the 3-position. Most preferably R.sup.5 is hydrogen and it is in the 3-position. Preferably R.sup.6 is in the 4-position. More preferably, R.sup.6 is hydrogen, chlorine, cyano, fluorine, trifluoromethyl or R.sup.b SO.sub.2 wherein R.sup.b is C.sub.1 -C.sub.4 alkyl, preferably methyl or C.sub.1 -C.sub.4 haloalkyl, preferably chloromethyl, difluoromethyl or trifluoromethyl.

Salts of the above-described compounds (as defined hereinafter) are included within the scope of the instant invention.

The compounds of this invention can have the following three structural formulae because of tautomerism: ##STR5## wherein R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and t are as defined above.

The circled proton on each of the three tautomers is reasonably labile. These protons are acidic and can be removed by reaction with a base to form a salt having an anion of the following three resonance forms: ##STR6## wherein R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7 and t are as defined above.

Examples of cations of these bases are inorganic cations such as alkali metals, e.g. lithium, sodium and potassium; the alkaline earth metals, e.g. calcium and magnesium or ammonium or organic cations such as substituted ammonium, sulfonium, sulfoxonium or phosphonium wherein the substituents are aliphatic or aromatic groups.

Those skilled in the art will recognize in considering the salts of this invention that varying degrees of association between the anion and cation will exist depending upon the nature of the cation. In some instances with a suitable cation, such as copper, the salt can exist in a chelated form.

The compounds of this invention and their salts are active herbicides of a general type. That is, they are herbicidally effective against a wide range of plant species. The method of controlling undesirable vegetation of the present invention comprises applying an herbicidally effective amount of the above described compounds to the area where control is desired.

The compounds of the present invention can be prepared by the following two-step general method.

The process proceeds via the production of an enol ester intermediate as shown in reaction (1). The final product is obtained by rearrangement of the enol ester as shown in reaction (2). The two reactions may be conducted as separate steps by isolation and recovery of the enol ester using conventional techniques prior to conducting step (2), or by addition of a cyanide source to the reaction medium after the formation of the enol ester, or in one step by inclusion of the cyanide source at the start of reaction (1). ##STR7## wherein t and R through R.sup.7 are as defined and Y is halogen, preferably chlorine, C.sub.1 -C.sub.4 alkyl--C(O)--O--, C.sub.1 -C.sub.4 alkoxy--C(O)--O-- or ##STR8## wherein R, R.sup.5 and R.sup.6 in this portion of the molecule are identical with those in the reactant shown above and the moderate base is as defined, preferably tri-C.sub.1 -C.sub.6 alkylamine, alkali metal carbonate or alkali metal phosphate.

Generally, in step (1) mole amounts of the oxolactam and substituted benzoyl reactant are used, along with a mole amount or excess of the base. The two reactants are combined in an organic solvent such as methylene chloride, toluene, ethyl acetate or dimethylformamide. The base or benzoyl reactant preferably are added to the reaction mixture with cooling. The mixture is stirred at 0.degree. C.-50.degree. C. until the reaction is substantially complete.

The reaction product is worked up by conventional techniques. ##STR9## wherein t and R through R.sup.7 are as defined.

Generally, in step (2) a mole of the enol ester intermediate is reacted with 1 to 4 moles of the base, preferably about 2 moles of moderate base and from 0.01 mole to about 0.5 mole or higher, preferably about 0.1 mole of the cyanide source (e.g., potassium cyanide or acetone cyanohydrin). The mixture is stirred in a reaction pot until the rearrangement is substantially complete at a temperature below 80.degree. C., preferably about 20.degree. C. to about 40.degree. C., and the desired product is recovered by conventional technques.

The term "cyanide source" refers to a substance or substances which under the rearrangement conditions consists of or generates hydrogen cyanide and/or cyanide anion.

The process is conducted in the presence of a catalytic amount of a source of cyanide anion and/or hydrogen cyanide, together with a molar excess, with respect to the enol ester, of a moderate base.

Preferred cyanide sources are alkali metal cyanides such as sodium and potassium cyanide; cyanohydrins of methyl alkyl ketones having from 1-4 carbon atoms in the alkyl groups, such as acetone or methyl isobutyl ketone cyanohydrins; cyanohydrins of benzaldehyde or of C.sub.2 -C.sub.5 aliphatic aldehydes such as acetaldehyde, propionaldehyde, etc., cyanohydrins; zinc cyanide; tri(lower alkyl) silyl cyanides, notably trimethyl silyl cyanide; and hydrogen cyanide itself. Hydrogen cyanide is considered most advantageous as it produces relatively rapid reaction and is inexpensive. Among cyanohydrins the preferred cyanide source is acetone cyanohydrin.

When salts are used as the active ingredient in the herbicidal compositions of this invention, it is recommended to use salts that are agriculturally acceptable.

The phytotoxic compositions of this invention can also contain other additives, for example, fertilizers, other herbicides and other pesticides, used as adjuvant or in combination with any of the abovedescribed adjuvants. Fertilizers useful in combination with the active ingredients include, for example, ammonium nitrate, urea and superphosphate.

The cyanide source is used in an amount up to about 50 mole percent based on the enol ester. It may be used in as little as about 1 mole percent to produce an acceptable rate of reaction at about 40 C. on a small scale. Larger scale reactions give more reproducible results with slightly higher catalyst levels of about 2 mole percent. Generally about 1-10 mole % of the cyanide source is preferred.

The process is conducted with a molar excess, with respect to the enol ester, of a moderate base. By the term "moderate base" is meant a substance which acts as a base yet whose strength or activity as a base lies between that of strong bases such as hydroxides (which could cause hydrolysis of the enol ester) and that of weak bases such as bicarbonates (which would not function effectively). Moderate bases suitable for use in this embodiment include both organic bases such as tertiary amines and inorganic bases such as alkali metal carbonates and phosphates. Suitable tertiary amines include trialkylamines such as triethylamine. Suitable inorganic bases include potassium carbonate and trisodium phosphate.

The base is used in an amount of from about 1 to about 4 moles per mole of enol ester, preferably about 2 moles per mole.

When the cyanide source is an alkali metal cyanide, particularly potassium cyanide, a phase transfer catalyst may be included in the reaction. Particularly suitable phase transfer catalysts are the Crown ethers.

A number of different solvents are useful in this process, depending on the nature of the acid chloride or the acylated product. A preferred solvent for this reaction is acetonitrile. Other solvents which may be employed, depending on the reactants or products include toluene, 1,2-dichloroethane, methylene chloride, ethyl acetate, dimethylformamide, and methyl isobutyl ketone (MIBK).

In general, depending on the nature of the reactants and the cyanide source, the rearrangement may be conducted at temperature up to about 50.degree. C.

The above described substituted benzoyl chlorides can be prepared from the corresponding substituted benzoic acids according to the teaching of Reagents for Organic Synthesis, Vol. I, L. F. Fieser and M. Fieser, pp. 767-769 (1967). ##STR10## wherein R, R.sup.5 and R.sup.6 are as previously defined.

The substituted benzoic acids can be prepared by a wide variety of general methods according to the teaching of The Chemistry of Carboxylic Acids and Esters, S. Patai, editor, J. Wiley and Sons, New York, N.Y. (1969) and Survey of Organic Synthesis, C. A. Buehler and D. F. Pearson, J. Wiley and Sons, (1970).

The following are three representative examples of the methods described therein. ##STR11## wherein R, R.sup.5 and R.sup.6 are as previously defined.

In reaction (a) the substituted benzonitrile is heated to reflux in aqueous sulfuric acid for several hours. The mixture is cooled and the reaction product is isolated by conventional techniques. ##STR12## wherein R, R.sup.5 and R.sup.6 are as previously defined.

In reaction (b) the substituted acetophenone is heated to reflux for several hours in an aqueous hypochlorite solution. The mixture is cooled and the reaction product is isolated by conventional techniques. ##STR13## wherein R, R.sup.5 and R.sup.6 are as defined and X is chlorine, bromine or iodine.

The substituted aromatic halide is allowed to react with magnesium in a solvent such as ether. The solution is then poured over crushed dry ice and the benzoic acid is isolated by conventional techniques.

The above-described 4-oxolactams can be prepared according to the teaching of V. J. Lee et al., J. American Chem. Soc., 100, 4225-4236 (1978).

The following example teaches the synthesis of a representative compound of this invention.

EXAMPLE 1

3-(2-Nitro-4-chlorobenzoyl)-1,5-dimethyl-4-oxovalerolactam ##STR14##

2-Nitro-4-chlorobenzoyl chloride (3.7 g, 17 mmol) and 1,5-dimethyl-4-oxovalerolactam (3.0 g, 17 mmol) were dissolved in 150 ml methylene chloride. Triethylamine (1.7 g, 17 mmol) was added and the resulting solution was stirred at room temperature for fifteen minutes. The solution was washed with dilute hydrochloric acid, 5% potassium carbonate and saturated sodium chloride, dried over magnesium sulfate and concentrated under vacuum. The residue was dissolved in 20 ml of acetonitrile. Triethylamine (1.7 g, 17 mmol) potassium cyanide (0.1 g, 1.5 mmol) and 18-crown-6 (0.1 g, 0.4 mmol) were added and the mixture stirred at room temperature for 20 minutes. After dilution with ether, the solution was washed with dilute hydrochloric acid and extracted with 5% potassium carbonate. The basic extract was acidified with hydrochloric acid and extracted with chloroform. The chloroform extract was washed with 10% cupric acetate, water, saturated sodium bicarbonate, and 2N hydrochloride acid. The chloroform layer was washed with water, dried ovr MgSO.sub.4 and evaporated to yield a yellow solid (2.0 g, m.p. 119.degree.-120.degree. C.) which was identified as the desired compound by nuclear magnetic resonance spectroscopy, infrared spectroscopy and mass spectroscopy.

The following is a table of certain selected compounds that are preparable according to the procedure described hereto. Compound numbers are assigned to each compound and are used throughout the remainder of the application.

TABLE I__________________________________________________________________________ ##STR15##Comp.No. R R.sup.1 R.sup.2 R.sup.3 R.sup.4 R.sup.5 R.sup.6 R.sup.7 t m.p. .degree.C.__________________________________________________________________________1 NO.sub.2 H H H H H 4-Cl n-C.sub.3 H.sub.7 1 oil2 NO.sub.2 H H n/a n/a H 4-Cl n-C.sub.3 H.sub.7 0 oil3 Cl H H H H H 4-SO.sub.2 CH.sub.3 n-C.sub.3 H.sub.7 1 oil4 NO.sub.2 H H H H H 4-Cl C.sub.2 H.sub.5 1 oil5 NO.sub.2 CH.sub.3 H H H H 4-Cl C.sub.2 H.sub.5 1 100-1076(a) NO.sub.2 CH.sub.3 H H H H 4-Cl CH.sub.3 1 119-1207 NO.sub.2 H H CH.sub.3 CH.sub.3 H 4-Cl CH.sub.3 1 130-1318 NO.sub.2 H H H H H 4-CN C.sub.2 H.sub.5 1 159-1609 CH.sub.3 H H H H 3-NO.sub.2 H C.sub.2 H.sub.5 1 oil10 CF3 H H CH.sub.3 CH.sub.3 H 4-CF.sub.3 CH.sub.3 1 86-9011 NO.sub.2 H H CH.sub.3 H H 4-Cl CH.sub.3 1 142-14312 NO.sub.2 CH.sub.3 H H H H 4-SO.sub.2 CH.sub.2 Cl C.sub.2 H.sub.5 1 oil13 NO.sub.2 H H H H H 4-SO.sub.2 CH.sub.2 Cl C.sub.2 H.sub.5 1 oil14 NO.sub.2 CH.sub.3 H H H H 4-SO.sub.2 CH.sub.2 Cl CH.sub.3 1 141-14215 NO.sub.2 CH.sub.3 H H H H 4-SO.sub.2 CH.sub.3 C.sub.2 H.sub.5 1 oil16 NO.sub.2 CH.sub.3 H H H H 4-SO.sub.2 CH.sub.3 CH.sub.3 1 semi-solid17 Cl CH.sub.3 H H H 3-OC.sub.2 H.sub.5 4-SO.sub.2 C.sub.2 H.sub.5 CH.sub. 3 1 oil18 NO.sub.2 CH.sub.3 CH.sub.3 CH.sub.3 H H 4-Cl CH.sub.3 1 oil19 NO.sub.2 CH.sub.3 CH.sub.3 H H H 4-SO.sub.2 CH.sub.2 Cl CH.sub.3 1 oil20 NO.sub.2 CH.sub.3 CH.sub.3 H H 4-SO.sub.2 CH.sub.3 CH.sub.3 1 178-17921 CH.sub.3 CH.sub.3 H H H 3-NO.sub.2 H C.sub.2 H.sub.5 1 semi-solid22 NO.sub.2 H H H H H 4-Cl ##STR16## 1 154 dec.23 NO.sub.2 H H H H H 4-Cl i-C.sub.3 H.sub.7 1 83-8524 NO.sub.2 H H H H H 4-SO.sub.2 CH.sub.2 Cl i-C.sub.3 H.sub.7 1 oil25 NO.sub.2 H H H H H 4-Cl n-C.sub.4 H.sub.9 1 oil26 NO.sub.2 H H H H H 4-SO.sub.2 CH.sub.2 Cl n-C.sub.4 H.sub.9 1 oil27 NO.sub.2 CH.sub.3 CH.sub.3O- H 4-Cl CH.sub.3 1 oil28 Cl CH.sub.3 CH.sub.3O- H 4-SO.sub.2 CH.sub.3 CH.sub.3 1 oil29 Cl CH.sub.3 CH.sub.3O- 3-OC.sub.2 H.sub.5 4-SO.sub.2 C.sub.2 H.sub.5 CH.sub.3 1 oil30 NO.sub.2 CH.sub.3 CH.sub.3O- H 4-Cl C.sub.2 H.sub.5 1 oil31 CH.sub.3 CH.sub.3 CH.sub.3O- 3-NO.sub.2 H n-C.sub.3 H.sub.7 1 oil32 NO.sub.2 CH.sub.3 CH.sub.3O- H 4-Cl C.sub.2 H.sub.5 1 oil33 CH.sub.3 CH.sub.3 CH.sub.3O- 3-NO.sub.2 H CH.sub.3 1 oil34 NO.sub.2 C.sub.2 H.sub.5 CH.sub.3O- H 4-Cl CH.sub.3 1 semi-solid35 CH.sub.3 C.sub.2 H.sub.5 CH.sub.3O- 3-NO.sub.2 H CH.sub.3 1 oil36 NO.sub.2 CH.sub.3 H H H H 4-Cl n-C.sub.3 H.sub.7 1 oil37 NO.sub.2 CH.sub.3 H H H H 4-CF.sub.3 n-C.sub.3 H.sub.7 1 oil__________________________________________________________________________ (a) Prepared in Example I. n/a = Not applicable when t = 0.

Herbicidal Screening Test

As previously mentioned, the herein described compounds produced in the above-described manner are phytotoxic compounds which are useful and valuable in controlling various plant species. Selected compounds of this invention were tested as herbicides in the following manner.

Pre-emergence herbicide test. On the day preceding treatment, seeds of seven different weed species are planted in loamy sand soil in individual rows using one species per row across the width of a flat. The weeds used are green foxtail (FT) (Setaria viridis), watergrass (WG) (Echinochloa crusgalli), wild oat (WO) (Avena fatua), annual morningglory (AMG) (Ipomoea lacunosa), velvetleaf (VL) (Abutilon theophrasti), Indian mustard (MD) (Brassica juncea) and yellow nutsedge (YNG) (Cyperus esculentus). Ample seeds are planted to give about 20 to 40 seedings per row, after emergence, depending upon the size of the plants.

Using an analytical balance, 600 milligrams (mg) of the compound to be tested are weighed out in a piece of glassine weighing paper. The paper and compound are placed in a 60 milliliter (ml) wide-mouth clear bottle and dissolved in 45 ml of acetone or substituted solvent. Eighteen ml of this solution are transferred to a 60 ml wide-mouth clear bottle and diluted with 22 ml of a water and acetone mixture (19:1) containing enough polyoxyethylene sorbitan monolaurate emulsifier to give a final solution of 0.5% (v/v). The solution is then sprayed on a seeded flat on a linear spray table calibrated to deliver 80 gallons per acre (748 L/ha). The application rate is 4 lb/acre (4.48 Kg/ha).

After treatment, the flats are placed in the greenhouse at a temperature of 70.degree. to 80.degree. F. and watered by sprinkling. Two weeks after treatment, the degree of injury or control is determined by comparison with untreated check plants of the same age. The injury rating from 0 to 100% is recorded for each species as percent control with 0% representing no injury and 100% representing complete control.

The results of the tests are shown in the following Table II.

TABLE II______________________________________Pre-Emergence Herbicidal ActivityApplication Rate-4.48 kg/haCmpd.No. FT WG WO AMG VL MD YNG______________________________________1 100 100 90 100 100 100 802 90 100 30 50 100 100 803 100 100 80 100 100 100 804 100 100 90 100 100 100 805 100 100 100 20 100 100 806 100 100 100 100 100 100 807 100 100 100 100 100 100 808 30 50 20 40 100 100 809 30 80 30 5 60 80 7010 100 90 20 10 90 100 8011 100 100 95 100 100 100 8012 100 100 100 100 100 100 8013 100 100 100 100 100 100 8014 100 100 100 100 100 100 8015 100 100 100 100 100 100 8016 100 95 100 100 100 100 8017 100 100 100 100 100 100 8018 100 90 100 100 95 100 8019 100 90 100 100 95 90 8020 100 90 100 100 100 75 8021 100 95 100 100 100 80 8022 85 30 20 100 100 10 6023 100 80 100 100 100 100 8024 100 60 100 100 100 100 8025 100 100 100 100 100 20 8026 100 100 100 100 100 100 8027 100 90 100 100 100 100 9028 100 80 100 100 100 100 9029 100 100 100 100 100 100 9030 100 95 100 100 100 100 8031 100 100 30 80 100 100 3032 100 100 100 100 100 100 8033 100 95 20 90 100 100 8034 100 90 20 20 100 100 7035 85 10 0 20 100 100 3036 100 100 100 20 100 100 8037 100 100 90 100 100 100 80______________________________________

Post-Emergence Herbicide Test: This test is conducted in an identical manner to the testing procedure for the pre-emergence herbicide test, except the seeds of the seven different weed species are planted 10-12 days before treatment. Also, watering of the treated flats is confined to the soil surface and not to the foliage of the sprouted plants.

The results of the post-emergence herbicide test are reported in Table III.

TABLE III______________________________________Post-Emergence Herbicidal ActivityApplication Rate-4.48 kg/haCmpd.No. FT WG WO AMG VL MD YNG______________________________________1 100 100 60 75 90 80 302 10 70 10 10 80 30 303 50 60 60 50 50 50 704 100 100 90 90 100 90 605 100 100 90 100 100 100 806 100 95 85 100 100 80 807 90 85 80 80 90 80 808 30 20 40 40 60 50 09 80 60 80 10 90 60 3010 80 80 80 50 90 90 8011 90 80 80 80 90 80 8012 90 80 70 80 90 80 6013 100 85 80 80 90 90 7014 80 80 60 80 80 80 8015 95 80 70 80 80 80 8016 100 80 85 80 90 80 8017 90 60 80 80 80 80 8018 100 80 80 80 80 60 6019 85 65 70 80 80 60 6020 70 50 60 80 80 60 5021 60 50 40 60 60 40 3022 10 10 20 85 85 75 3023 60 80 90 90 90 80 7024 10 10 60 80 80 60 3025 100 90 90 90 90 60 5026 100 80 90 100 100 95 3027 100 100 100 100 100 100 9028 85 90 95 100 100 100 8029 100 100 100 100 100 100 8030 100 100 100 100 100 100 8031 80 30 30 100 100 100 3032 100 100 100 100 100 100 10033 100 80 100 100 100 100 6534 100 30 30 100 100 100 3035 0 0 0 70 100 100 036 100 100 100 90 100 100 7037 100 100 100 100 100 100 80______________________________________

The compounds of the present invention and their salts are useful as herbicides and can be applied in a variety of ways at various concentrations. In practice, the compounds or salts are formulated into herbicidal compositions, by admixture, in herbicidally effective amounts, with the adjuvants and carriers normally employed for facilitating the dispersion of active ingredients for agricultural applications, recognizing the fact that the formulation and mode of application of a toxicant may affect the activity of the materials in a given application. Thus, these active herbicidal compounds or salts can be formulated as granules of relatively large particle size, as wettable powders, as emulsifiable concentrates, as powdery dusts, as flowables, as solutions or as any of several other known types of formulations, depending upon the desired mode of application. These formulations may contain as little as about 0.5% to as much as about 95% or more by weight of active ingredient. A herbicidally effective amount depends upon the nature of the seeds or plants to be controlled and the rate of application varies from about 0.01 to approximately 10 pounds per acre, preferably from about 0.02 to about 4 pounds per acre.

Wettable powders are in the form of finely divided particles which disperse readily in water or other dispersants. The wettable powder is ultimately applied to the soil either as a dry dust or as a dispersion in water or other liquid. Typical carriers for wettable powders include fuller's earth, kaolin clays, silicas and other readily wet organic or inorganic diluents. Wettable powders normally are prepared to contain about 5% to about 95% of the active ingredient and usually also contain a small amount of wetting, dispersing, or emulsifying agent to facilitate wetting and dispersion.

Emulsifiable concentrates are homogeneous liquid compositions which are dispersible in water or other dispersant, and may consist entirely of the active compound or salt with a liquid or solid emulsifying agent, or may also contain a liquid carrier, such as xylene, heavy aromatic naphthal, isophorone and other non-volatile organic solvents. For herbicidal application, these concentrates are dispersed in water or other liquid carrier and normally applied as a spray to the area to be treated. The percentage by weight of the essential active ingredient may vary according to the manner in which the composition is to be applied, but in general comprises about 0.5% to 95% of active ingredient by weight of the herbicidal composition.

Granular formulations wherein the toxicant is carried on relatively coarse particles, are usually applied without dilution to the area in which suppression of vegetation is desired. Typical carriers for granular formulations include sand, fuller's earth, attapulgite clay, bentonite clays, montmorillonite clay, vermiculite, perlite and other organic or inorganic materials which absorb or which may be coated with the toxicant. Granular formulations normally are prepared to contain about 5% to about 25% active ingredients which may include surface-active agents such heavy aromatic naphthas, kerosene or other petroleum fractions, or vegetable oils; and/or stickers such as dextrins, glue or synthetic resins.

Typical wetting, dispersing or emulsifying agents used in agricultural formulations include, for example, the alkyl and alkylaryl sulfonates and sulfates and their salts; polyhydric alcohols; polyethoxylated alcohols; esters and fatty amines; and other types of surface-active agents, many of which are available in commerce. The surface-active agent, when used, normally comprises from 0.1% to 15% by weight of the herbicidal composition.

Dusts, which are free-flowing admixtures of the active ingredient with finely divided solid such as talc, clays, flours and other organic and inorganic solids which act as dispersants and carriers for the toxicant, are useful formulations for soil-incorporating application.

Pastes, which are homogeneous suspensions of a finely divided solid toxicant in a liquid carrier such as water or oil, are employed for specific purposes. These formulations normally contain about 5% to about 95% of active ingredient by weight, and may also contain small amounts of a wetting, dispersing or emulsifying agent to facilitate dispersion. For application, the pastes are normally diluted and applied as a spray to the area to be affected.

Other useful formulations for herbicidal applications include simple solutions of the active ingredient in a dispersant in which it is completely soluble at the desired concentration, such as acetone, alkylated naphthalenes, xylene and other organic solvents. Pressurized sprays, typically aerosols, wherein the active ingredient is dispersed in finely-divided form as a result of vaporization of a low boiling dispersant solvent carrier, such as the Freons, may also be used.

The phytotoxic compositions of this invention can be applied to the plants in the conventional manner. Thus, the dust and liquid compositions can be applied to the plant by the use of power-dusters, boom and hand sprayers and spray dusters. The compositions can also be applied from airplanes as a dust or a spray or by rope wick applications because they are effective in very low dosages. In order to modify or control growth of germinating seeds or emerging seedlings, as a typical example, the dust and liquid compositions can be applied to the soil according to conventional methods and can be distributed in the soil to a depth of at least 1/2 inch below the soil surface. It is not necessay that the phytotoxic compositions be mechanically admixed with the soil particles since these compositions can also be applied merely by spraying or sprinkling the surface of the soil. The phytotoxic compositions of this invention can also be applied by addition to irrigation water supplied to the field to be treated. This method of application permits the penetration of the compositions into the soil as the water is absorbed therein. Dust compositions, granular compositions or liquid formulations applied to the surface of the soil can be distributed below the surface of the soil by conventional means such as discing, dragging or mixing operations. In the following examples the herbicidal compound can be substituted with the herbicidal salt of the compound.

______________________________________EMULSIFIABLE CONCENTRATE FORMULATIONSGeneral Formula with Ranges Specific Formula______________________________________Herbicidal 5-55 herbicidal 24compound compoundsurfactant(s) 5-25 proprietary 10 blend of oil-solvent(s) 20-90 soluble 100% sulfonates and polyoxyethylene ethers polar solvent 27 petroleum 39 hydrocarbon 100%WETTABLE POWDER FORMULATIONSherbicidal 3-90 herbicidal 80compound compoundwetting agent 0.5-2 sodium dialkyl 0.5 naphthalenedispersing agent 1-8 sulfonatediluent(s) 8.5-87 sodium 7 100% lignosulfonate 7 attapulgite clay 12.5 100%EXTRUDED GRANULAR FORMULATIONSherbicidal 1- 20 herbicidal 10compound compoundbinding agent 0-10 lignin sulfonate 5diluent(s) 70-99 calcium carbonate 85 100% 100%FLOWABLE FORMULATIONSherbicidal 20-70 herbicidal 45compound compoundsurfactant(s) 1-10 polyoxyethylene 5 ethersuspending agent(s) 0.05-1 attagel 0.05antifreeze agent 1-10 propylene glycol 10antimicrobial agent 1-10 1,2-benzisothia- 0.03 zoline-3-oneantifoam agent 0.1-1 silicone defoamer 0.02solvent 7.95-77.85 water 39.9 100% 100%______________________________________

When salts are used as the active ingredient in the herbicidal compositions of this invention it is recommended to use salts that are agriculturally acceptable.

The phytotoxic compositions of this invention can also contain other additives, for example, fertilizers, other herbicides and other pesticides, used as adjuvant or in combination with any of the abovedescribed adjuvants. Fertilizers useful in combination with the active ingredients include, for example, ammonium nitrate, urea and superphosphate.

Claims

1. The method of controlling undesirable vegetation comprising applying to the area where control is desired, an herbicidally effective amount of a compound having the formula ##STR17## wherein R is halogen; C.sub.1 -C.sub.2 alkyl; C.sub.1 -C.sub.2 alkoxy; nitro; cyano; C.sub.1 -C.sub.2 haloalkyl; or R.sup.a SO.sub.n -- wherein n is 0 or 2 and R.sup.a is C.sub.1 -C.sub.2 alkyl;

R.sup.1 is hydrogen or C.sub.1 -C.sub.4 alkyl;

R.sup.2 is hydrogen or C.sub.1 -C.sub.4 alkyl; or

R.sup.1 and R.sup.2 together are alkylene having 2-5 atoms;

R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl;

R.sup.4 is hydrogen or C.sub.1 -C.sub.4 alkyl; or

R.sup.3 and R.sup.4 is together are carbonyl; and

R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen; (3) C.sub.1 -C.sub.4 alkyl; (4) C.sub.1 -C.sub.4 alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C.sub.1 -C.sub.4 haloalkyl; (9) R.sup.b SO.sub.m -- wherein m is the integer 0, 1 or 2; and R.sup.b is (a) C.sub.1 -C.sub.4 alkyl; (b) C.sub.1 -C.sub.4 alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.e C(O)-- wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; (12) --SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; or (13) --N(R.sup.c)C(O)R.sup.d wherein R.sup.c and R.sup.d

R.sup.7 is C.sub.1 -C.sub.4 alkyl or phenyl; and

t is the integer 1 are as defined and their salts.

2. The method of claim 1 wherein R is chlorine, bromine, C.sub.1 -C.sub.2 alkyl, C.sub.1 -C.sub.2 alkoxy, cyano, nitro, C.sub.1 -C.sub.2 alkylthio or C.sub.1 -C.sub.2 alkylsulfonyl; R.sup.1 is hydrogen or methyl; R.sup.2 is hydrogen or methyl; R.sup.3 is hydrogen or methyl; R.sup.4 is hydrogen or methyl; or R.sup.3 and R.sup.4 together are carbonyl; R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen; (3) C.sub.1 -C.sub.4 alkyl; (4) C.sub.1 -C.sub.4 alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C.sub.1 -C.sub.4 haloalkyl; (9) R.sup.b SO.sub.m -- wherein m is the integer 0, 1 or 2; and R.sup.b is (a) C.sub.1 -C.sub.4 alkyl; (b) C.sub.1 -C.sub.4 alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.3 C(O)-- wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; (12) SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; or (13) --N--(R.sup.c)C(O)R.sup.d wherein R.sup.c and R.sup.d are as defined; R.sup.7 is C.sub.1 -C.sub.4 alkyl; and t is the integer 1.

3. The method of claim 2 wherein R.sup.5 and R.sup.6 are independently are hydrogen; chlorine; fluorine; bromine; methyl; methoxy; trifluoromethoxy; cyano; nitro; trifluoromethyl; R.sup.b SO.sub.m -- wherein m is the integer 2 and R.sup.b is methyl, chloromethyl, trifluoromethyl, cyanomethyl, ethyl, or n-propyl; --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; R.sup.e C(O)-- where R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy or SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined and R.sup.5 is in the 3-position and R.sup.6 is in the 4-position.

4. The method of claim 2 wherein R.sup.5 is hydrogen and R.sup.6 is hydrogen, chlorine, bromine, fluorine, trifluoromethyl, cyano or R.sup.b SO.sub.2 wherein R.sup.b is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 haloalkyl.

5. The method of claim 3 wherein R is nitro, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine and R.sup.7 is n-propyl.

6. The method of claim 3 wherein R is chlorine, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.3 and R.sup.7 is n-propyl.

7. The method of claim 3 wherein R is nitro, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 i hydrogen, R.sup.6 is 4-chlorine and R.sup.7 is ethyl.

8. The method of claim 3 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine, and R.sup.7 is methyl.

9. The method of claim 3 wherein R is nitro, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is methyl, R.sup.4 is methyl, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine and R.sup.7 is methyl.

10. The method of claim 3 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.2 Cl, and R.sup.7 is ethyl.

11. The method of claim 3 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.2 Cl and R.sup.7 is methyl.

12. The method of claim 3 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.3 and R.sup.7 is ethyl.

13. The method of claim 2 wherein R.sup.5 is hydrogen.

14. The method of claim 3 wherein R.sup.5 is hydrogen.

15. An herbicidal composition comprising an herbicidally active 3-(benzoyl)-4-oxolactam or their salts and an inert carrier therefor.

16. The herbicidal composition of claim 15 wherein the 3-(benzoyl)-4-oxolactam is a compound of the formula ##STR18## wherein R is halogen; C.sub.1 -C.sub.2 alkyl; C.sub.1 -C.sub.2 alkoxy; nitro; cyano; C.sub.1 -C.sub.2 haloalkyl; or R.sup.a SO.sub.n -- wherein n is 0 or 2 and R.sup.a is C.sub.1 -C.sub.2 alkyl;

R.sup.1 is hydrogen or C.sub.1 -C.sub.4 alkyl;

R.sup.2 is hydrogen or C.sub.1 -C.sub.4 alkyl; or

R.sup.1 and R.sup.2 together are alkylene having 2-5 carbon atoms;

R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl;

R.sup.4 is hydrogen or C.sub.1 -C.sub.4 alkyl; or

R.sup.3 and R.sup.4 together are carbonyl; and

R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen; (3) C.sub.1 -C.sub.4 alkyl; (4) C.sub.1 -C.sub.4 alkoxy; (5) trifluoromethyl; (6) cyano; (7) nitro; (8) C.sub.1 -C.sub.4 haloalkyl; (9) R.sup.b SO.sub.m -- wherein m is the integer 0, 1 or 2; and R.sup.b is (a) C.sub.1 -C.sub.4 alkyl; (b) C.sub.1 -C.sub.4 alkyl subtituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.e C(O)-- wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; or (12) --SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; and (13) --N(R.sup.c )C(O)R.sup.d wherein R.sup.c and R.sup.d are as defined;

R.sup.7 is C.sub.1 -C.sub.4 alkyl or phenyl; and

t is the integer 1 and their salts.

17. The composition of claim 16 wherein R is chlorine, bromine, C.sub.1 -C.sub.2 alkyl, C.sub.1 -C.sub.2 alkoxy, cyano, nitro, C.sub.1 -C.sub.2 alkylthio or C.sub.1 -C.sub.2 alkylsulfonyl; R.sup.1 is hydrogen or methyl; R.sup.2 is hydrogen or methyl; R.sup.3 is hydrogen or methyl; R.sup.4 is hydrogen or methyl; or R.sup.3 and R.sup.4 together are carbonyl; R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen; (3) C.sub.1 -C.sub.4 alkyl; (4) C.sub.1 -C.sub.4 alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (8) C.sub.1 -C.sub.4 haloalkyl; (9) R.sup.b SO.sub.m -- wherein m is the integer 0, 1 or 2; and R.sup.b is (a) C.sub.1 -C.sub.4 alkyl; (b) C.sub.1 -C.sub.4 alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.e C(O)-- wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; (12) SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; or (13) --N--(R.sup.c)C(O)R.sup.d wherein R.sup.c and R.sup.d are as defined; R.sup.7 is C.sub.1 -C.sub.4 alkyl; and t is 1.

18. The composition of claim 17 wherein R.sup.5 and R.sup.6 are independently are hydrogen; chlorine; fluorine; bromine; methyl; methoxy; trifluoromethoxy; cyano; nitro; trifluoromethyl; R.sup.b SO.sub.n -- wherein n is the integer 2 and R.sup.b is methyl, chloromethyl, trifluoromethyl, cyanomethyl, ethyl, or n-propyl; --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; R.sup.e C(O)-- where R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy or SO.sub.2 N wherein R.sup.c and R.sup.d are as defined and R.sup.5 is in the 3-position and R.sup.6 is in the 4-position.

19. The composition of claim 17 wherein R.sup.5 is hydrogen and R.sup.6 is hydrogen, chlorine, bromine, fluorine, trifluoromethyl, cyano or R.sup.b SO.sub.2 wherein R.sup.b is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 haloalkyl.

20. The composition of claim 16 wherein R is nitro, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine and R.sup.7 is n-C.sub.3 H.sub.7.

21. The composition of claim 16 wherein R is chlorine, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.3 and R.sup.7 is n-propyl.

22. The composition of claim 16 wherein R is nitro, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine and R.sup.7 is ethyl.

23. The composition of claim 16 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine, and R.sup.7 is methyl.

24. The composition of claim 16 wherein R is nitro, R.sup.1 is hydrogen, R.sup.2 is hydrogen, R.sup.3 is methyl, R.sup.4 is methyl, R.sup.5 is hydrogen, R.sup.6 is 4-chlorine and R.sup.7 is methyl.

25. The composition of claim 16 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.2 Cl, and R.sup.7 is ethyl.

26. The composition of claim 16 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.2 Cl and R.sup.7 is CH.sub.3.

27. The composition of claim 16 wherein R is nitro, R.sup.1 is methyl, R.sup.2 is hydrogen, R.sup.3 is hydrogen, R.sup.4 is hydrogen, R.sup.5 is hydrogen, R.sup.6 is 4-SO.sub.2 CH.sub.3 and R.sup.7 is ethyl.

28. The composition of claim 17 wherein R.sup.5 is hydrogen.

29. The composition of claim 17 wherein R.sup.5 is hydrogen.

30. The method of controlling undesirable vegetation comprising applying to the area where control is desired, an herbicidal composition comprising an herbicidally active 3-(benzoyl)-4-oxolactam or their salts and an inert carrier therefor.

31. The method of claim 30 wherein the 3-(benzoyl)-4-oxolactam is a compound of the formula ##STR19## wherein R is halogen; C.sub.1 -C.sub.2 alkyl; nitro; cyano; C.sub.1 -C.sub.2 haloalkyl; or R.sup.a SO.sub.n -- wherein n is 0 or 2 and R.sup.a is C.sub.1 -C.sub.2 alkyl;

R.sup.1 is hydrogen or C.sub.1 -C.sub.4 alkyl;

R.sup.2 is hydrogen or C.sub.1 -C.sub.4 alkyl; or

R.sup.1 and R.sup.2 together are alkylene having 2-5 carbon atoms;

R.sup.3 is hydrogen or C.sub.1 -C.sub.4 alkyl;

R.sup.4 is hydrogen or C.sub.1 -C.sub.4 alkyl; or

R.sup.3 and R.sup.4 together are carbonyl; and

R.sup.5 and R.sup.6 independently are (1) hydrogen; (2) halogen; (3) C8) alkyl; (4) C.sub.1 -C.sub.4 alkoxy; (5) trifluoromethoxy; (6) cyano; (7) nitro; (C.sub.1 -C.sub.4 haloalkyl; (9) R.sup.b SO.sub.m -- wherein m is the integer 0, 1 or 2; and R.sup.b is (a) C.sub.1 -C.sub.4 alkyl; (b) C.sub.1 -C.sub.4 alkyl substituted with halogen or cyano; (c) phenyl; or (d) benzyl; (10) --NR.sup.c R.sup.d wherein R.sup.c and R.sup.d independently are hydrogen or C.sub.1 -C.sub.4 alkyl; (11) R.sup.e C(O)-- wherein R.sup.e is C.sub.1 -C.sub.4 alkyl or C.sub.1 -C.sub.4 alkoxy; or (12) --SO.sub.2 NR.sup.c R.sup.d wherein R.sup.c and R.sup.d are as defined; and (13) --N(R.sup.c)C(O)R.sup.d wherein R.sup.c and R.sup.d are as defined;

R.sup.7 is C.sub.1 -C.sub.4 alkyl or phenyl; and

t is the integer 1.