OXAZOLYL-SUBSTITUTED DIAZAHETEROCYCLES

Abstract: Compounds of the formula:- wherein Z is -COCO-, COS, COCHOH, or CH₂XCH₂; X is O or NR₃; one of R₁ and R₂ is a substituted oxazolyl group and other is a defined hydrocarbyl group. The preparation of such com­ pounds, their use as herbicides and herbicidal compositions containing them.

Description: OXAZOLYL-SUBSTITUTED DIAZAMETEROCYCLES This invention relates to certain oxazolyl-substituted diaza heterocycles which have been found to possess herbicidal activity, the preparation of such compounds, herbicidal compositions containing them, and to their use in combating undesired plant growth, Accordingly, the present invention provides a compound of the formula EMI1.1 wherein Z is a bivalent group of the formula -oo-co-, -CO-S-, -CO-CHCH-, or-CH2-X-CH2 ; X is an oxygen atan or the group N-R3 wherein R3 is an alkyl group of from 1 to 3 carbon atans, or a cyclopropyl or methylcyclopropyl group ; ; one of R1 and R2 is an oxazolyl group of formula IIA EMI1.2 or, when Z is -CO-CO-, or -CO-CHCH-, may alternatively be the iscmeric formula IIB EMI2.1 and the other is an alkyl, haloalkyl or alkoxy group of 1 to 3 carbon atoms, a cycloalkyl group of 3 to 6 carbon atans or an alkenyl group of 3 to 5 carbon atoms. and R4 is a group containing 3 to 5 carbon atans which is an alkyl, alkanyl, alkynyl, alkoxyalkyl, alkylthioalkyl, alkylsulphinylalkyl, alkylsulphonylalkyl, cycloalkyl, alkylcycloalkyl or haloalkyl group; provided that when Z is -CO-CHOH then h is not haloalkyl and R4 is not alkoxyalkyl ; and when Z is -CH2-X-CH2- then R4 is not beloalkyl, In these compounds, each alkyl, alkoxy, alkenyl and alkynyl Society suitably is either straight-chain or branched-chain in configuration. The term "halo" --- i.e., halogen --- designates one of chlorine, branine and fluorine. Preferred alkylthioalkyl, alkylsulfinylalkyl and alkylsulfonylalkyl moisties are those of the formula : EMI2.2 wherein n is zero, one or two. Preferred compounds are those wherein one of RI and represents an alkyl or alkawy, especially methyl or methoxy, group; and those wherein R4 represents an alkyl, alkynyl, alkoxyalkyl or alkylcycloalkyl, especially butyl, in particular tartiary butyl, ethynylpropyl, methoxybutyl or methylcyclopropyl, group. It is also preferred that the oxazolyl sustituent has the isaeric form given in formula IIA, especially preferred being such carps in which R4 is terary butyl. The invention also provides a process for the preparation of the compounds of the general formula I as defined above. For the compounds wherein Z represents -CO-CO-, -CO-S-, or -CD-CHOH, the compounds can be prepared by warming the appropriate urea of formula III EMI3.1 with, respectively, oxalyl chloride, (chlorothio)formyl chloride or glyoxylic acid (conveniently as the hydrate), in the presence of an inert solvent. In the first two cases the reaction may be represented by the equation: EMI3.2 In the third case the reaction may be represented by the equation: EMI3.3 In same cases, because of the method of preparation, the urea reactant may be of the formula IVA or IVB EMI3.4 In sane cases, the alkylaminocarbonyl Society will be split off when the urea is heated in the presence of the chloride reactant. In other cases, it will be desirable, or necessary, to treat the urea of Formula IV with a base to split off the alkylaminocarlxmyl moiety before the urea is treated with the chloride reactant. This procedure is illustrated in Example 6, hereinafter. Treatment of the urea with oxalyl chloride or glyoxylic acid is conveniently conducted by adding the chloride or acid to a stirred solution of the urea in an inert solvent such as methylene chloride or toluene and refluxing the mixture for a sufficient tine to enable the reaction to go to catpletion. The hydrogen chloride by-product in the first case may be removed as a gas as it is evolved, or absorbed by the incorporation of a hydrogen chloride acceptor such as a tertiary nitrogen base. The water by-product in the second case is preferably ramoved as a vapour as it evolves. Treatment of the urea with (chlorothio)formyl chloride is conveniently conducted by adding the chloride to a stirred solution of the urea in a solvent at about roam temperature in the presence of a tertiary nitrogen base as hydrogen chloride acceptor, chilling the resulting mixture to about OOC, slowly adding the amine base thereto, then warming and stirring the mixture until the reaction is complete. In sane cases, it may be found to be deairable to use a disulfide (R-S-S-8-Cl, wherein R is a hydrocarbon moiety) or ester (Cl-S-O-O-R) instead of (chlorothio)formul chloride. In auch cases, the intermediate product is cyclized by heat, in the case of the ester the cyclization being catalyzed by a base. Those catpounds wherein Z is -CH20CH2- can be prepared by treating the appropriate urea (Formula III) with paraformaldehyde in an inert solvent and in the presence of an acid, such as p-toluenesulfonic acid, as catalyst, the reaction proceeding according to the equation: EMI4.1 EMI5.1 The treatment is conveniently conducted by heating a mixture of the urea, the paraformaldehydet catalyst and solvent at a moderately elevated temperature -- for example, 60-900C. Aromatic hydrocarbons, such as toluene, are suitable solvents. If desired, a small amount --e.g., 10-30% of the amount of the amine, on a molar basis - may be included as a promotar. Those compounds wherein Z is EMI5.2 can be prepared by treating a solution of the appropriate urea EMI5.3 in an inert solvent with aqueous formaldehyde and treating the resulting mixture with the appropriate amine, -NH2. The reaction proceeds according to the equation: : EMI5.4 The a treatment is conveniently conducted by slowly adding the formaldehyde solution to a stirred solution of the urea in the solvent, at room temperature, cooling if needed to maintain the temperature of the mixture below about 35 C, then slowly adding the amine, again cooling the nixture if needed to maintain its temperature below about 350 C. It may be found desirable to warm the mixture - for example, on a water bath, or even reflux it - after the amine has been added, to ensure completion of the reaction. Suitable solvents are aprotic liquids, such as dimethylformamide, dimethyl sulfoxide and sulfolane. Workup of the reaction mixture, isolation of the product and its purification are effected by conventional techniques, as illustrated in the examples, hereinafter. Most of the oxazolyurea precursors (Formula III) are known ccmpconds: U.S. patent No. 4,062,861. Those wherein R4 represents a moiety EMI6.1 can be prepared by methods shown in that patent, the precursor amine being prepared from the nitrile, which in turn is prepared fran methyl 2-methyl-2-methylthiopropionate, according to procedures described in Example 6, hereinafter. The ester can be prepared fran methyl 2-bromo-2-methylpropionate (C.C. Price and E.C. Coyner, J. any Chem. Soc., (1940) 62, 1306-7) by the procedure shown in U.S. patent 3,994,997 for the preparation of the ethyl ester. These compounds of Formula I wherein R4 is the moiety EMI6.2 wherein n is one or two, can be prepared by conventional oxidation of the corresponding ocooounds of Formula I wherein n is zero. The oxidations can be effected be using such oxidizing reagents as hydrogen peroxide/acetic acid, peracids (for example meta-chloroperbenzoic acid), sodium mstaperiodate, chromic acid/acetic acid, nitric acid, or potassium peranganate/acetic acid (or acetone), as described in "Methoden der Organischen Chemie", (Houben-Weyl), Schewfel-, Selen-, und Tellur-Verbindungen, vol. IX, pp. 207 & 208, Thieme Verlag, Stuttgart, Germany (1955). me e oxazolylamine precursor wherein R4 = tertiary-butyl is the subject of British patent No. 2,014,992. The others can be prepared by the procedures described in that patent. Preparation of particular species of the precursor gamines are shown in the exarrples, hereinafter. The preparation, isolation and testing of typical individual species of the compounds of Formula I are described in the examples, following. me class of compounds is further illustrated and exemplified by the following further individual species, all of which are specifically conemplated in this invention. In the interest of brevity, in the identification of these species, the compounds are identified by reference to the meaning of the substituents in formula I, grouped according to the different meanings for Z. (I)Z denotes -CO-CO-. This group is considered as being made up of two sub-classes: SubclassA, wherein the oxazolyl Society is of Formula IIA, and Subclass B, wherein the oxazolyl Society is of Formula IIB. The follawing are the species in question: Species NO. R2 R4 Subclass A: 1 methoxy tertiary-butyl ((CH3)3C-) 2 cyclopropyl tertiary-butyl 3 allyl tertiary-butyl 4 propargyl tertiary-butyl (CH=C-CH2-) 5 methyl cyclopropyl 6 methyl 1-methyl-1-methylthioethyl (CH3-5-C(CH3)2-) 7 methyl 1-methyl-1-methylsulfenyl ethyl (CHE-8(O)-C(CH3)20-) 8 methyl 1-methyl-1-methylsulfonyl ethyl (CH3-S(O)2-C(CH3)2-) Species No. R2 R4 Sobclass B: 9 methyl tertiary-butyl 10 methyl 1,1-dimethyl-2-propynyl (CH=C-C(CH3)2-) 11 methoxy 1,1-dimethyl-2-propynyl 12 methyl cyclopropyl 13 methoxy tertiary-butyl 14 allyl tertiary-butyl 15 propargyl tertiary-butyl (II)Z denotes -CD-S-. This group is considered as being made up of two sub-classes: Subclass A, wherein R1 is the oxazolyl moiety, and Subclass B, wherein R2 is the oxazolyl moiety. The following are the species in question: EMI8.1 <tb> Species <tb> No. <SEP> R2 <SEP> R4 <tb> Subclass <SEP> A: : <tb> <SEP> 16 <SEP> methoxy <SEP> tertiary-butyl <tb> <SEP> ((CH3)3C-) <tb> <SEP> 17 <SEP> cyclopropyl <SEP> tertiaryibutyl <tb> <SEP> 18 <SEP> isopropyl <SEP> tertiary-butyl <tb> <SEP> 19 <SEP> methyl <SEP> l,l-dimeEhyl-2-propyn-l-yl <tb> <SEP> (HD=C-C(CH3)2-) <tb> <SEP> 20 <SEP> methyl <SEP> 1tthylcyclopiopyl <tb> <SEP> (t%3?) <tb> <SEP> 21 <SEP> methyl <SEP> 2-methoxy-l,l-di-methylethyl <tb> <SEP> (CH3+CH2-C(CH3)2 <SEP> ) <tb> <SEP> 22 <SEP> methyl <SEP> l-methyl-l-methylthioethyl <tb> <SEP> (CH3-S-C(CH3)2 <tb> <SEP> 23 <SEP> methyl <SEP> l-methyl-l-methylsulfenyl <tb> <SEP> ethyl(CH3-S(O)-C(CH3)2-) <tb> <SEP> 24 <SEP> methyl <SEP> l-methyl-l-methylsulfonyl <tb> <SEP> ethyl <SEP> (CH3-S <SEP> (O) <SEP> 2-CcCH3, <SEP> .-) <tb> Subclass B: R1 R4 25 methyl 1,1-dimethyl-2-propyn-1-yl 26 methoxy tertiary-butyl (III)Z denotes -CO-CHOH-. This group is considered as being made up of two subclasses: Subsclass A, wherein the oxazolyl Society is R1, and Subclass B, wherein the oxazolyl moiety is The following are the species in question: Species No. R2 R4 Subclass A: 27 methoxy tertiary-butyl ((CH3)3c-) 28 cyclopropyl tertiary-butyl 29 allyl tertiary-butyl 30 propargyl tartiary-butyl (CH=C-CH2-) 31 methyl cyclopropyl 32 methyl 1,1-dimethyl-2-propynyl (CH=C-C(CH3)2-) 33 cyclopropyl 1,1-dimethyl-2-propynyl 34 methoxy 1,1-dimethyl-2-propynyl 35 methyl 1-methyl-1-methylthioethyl (CH3-S-C(CH3)2 36 methyl 1-methyl-1-methylsulfenyl ethyl(CH3-S(O)-C(CH3)2-) 37 methyl 1-methyl-1-methylsulfonyl ethyl(CH3-S(O)2-C(CH3)2-) R1 R4 Subclass B: : 38 methyl 1,1-dimethyl-2-propynyl 39 methoxy 1,1-dimethyl-2-propynyl 40 methyl cycloprqpyl 41 methoxy tertiary-butyl 42 allyl tertiary-butyl 43 propargyl tertiary-butyl Species No. R1 R4 Subclass B : 44 cycloprcpyl tertiary-butyl 45 methyl 1-methylcyclopropyl (TV) Z dcts EMI10.1 <tb> Species <tb> No. <SEP> R3 <SEP> h <SEP> RI <tb> IN-R, <tb> a > N-Et3 <tb> <SEP> 46 <SEP> methyl <SEP> cycloprcpyl <SEP> tertiary-butyl <tb> <SEP> ((C)3C-) <tb> <SEP> 47 <SEP> methyl <SEP> allyl <SEP> tertiary-butyl <tb> <SEP> 48 <SEP> methyl <SEP> prapargyl <SEP> l-meEhylcycloproRyl <tb> <SEP> (CE=CT2-) <SEP> 1 <tb> <SEP> 3 <tb> <SEP> 49 <SEP> methyl <SEP> methyl <SEP> cyclopropyl <tb> <SEP> 50 <SEP> methyl <SEP> itthooy <SEP> 1, <SEP> 1,1-dimethy1-2-prq?yny1 <tb> <SEP> (CH=C-C(C%)2-) <tb> <SEP> 51 <SEP> prcQargyl <SEP> cyclopropyl <SEP> 1,1-dimethy1-2-propynyl <tb> <SEP> 52 <SEP> methyl <SEP> 1 <SEP> e <SEP> 1thyl- <SEP> 1thylthioethyl <tb> <SEP> (C <SEP> %-S-C(C <SEP> %)2-) <tb> <SEP> 53 <SEP> methyl <SEP> l-methyl-l-methylsulfenyl <tb> <SEP> ethyl <SEP> (CH,-S <SEP> (O)C <SEP> (C183) <SEP> Z) <tb> <SEP> 54 <SEP> methyl <SEP> 1-irethyl-l-rethyl <SEP> sulfonyl <tb> <SEP> ethyl(CH3-S(O)2-C(CH3)2-) <tb> X <SEP> = <SEP> p <tb> <SEP> 55 <SEP> cyclaprapyl <SEP> tertiaryibutyl <tb> <SEP> 56 <SEP> methyl <SEP> 1,1-dimeEhyl-2-propynyl <tb> <SEP> 57 <SEP> methoxy <SEP> 1,1-dimethyl-2-pGopyqyl <tb> <SEP> 58 <SEP> q <SEP> cyclopropyl <SEP> 1,1-dimethyl-2-prcFynyl <tb> Compounds of Formula I have been found to affect adversely the growth of certain plants which are commonly considered as weeds, and also to have selectivity with respect to sane crop plants - i.e., they control weeds at dosages at which they do not significantly harm the crop plants. Compounds of Formula I appear to be effective when applied preemergance or preplant incorporated (applied to the soil before the seeds have sprouted) or when applied postemergence (applied to the foliage of the growing plant). Some appear to be somewhat morse effective when applied pre-emergence than when applied postamergence, Accordingly, the invention includes the use as a herbicide of a compound of formula I, and also a method of combating undesired plant growth at a locus by applying to the locus an effective amount of a compound of formula I. In the case where it is desired to control weeds in crop plantings, it is of course preferable to employ the lowest dosage that will control the weeds, for this will minimize any possible deleterious effect of the compound upon the crop plants. For application, the compound generally is applied most effectively by formulating it with a suitable inert carrier or surface-active agent, or both. The invention, therefore, also includes a herbicidal composition comprising a carrier or surface-active agent, or both, and as active ingredient at least one compound of Formula I, and a method of making such a compositicn which comprises bringing a compound of formula I into association with at least one carrier. 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 be a plant, seed or soil, or to facilitate storage, transport or 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 herbicidal compositions may be used. Preferably oompositions according to the invention contain 0.5 to 95% by weight of active ingredient. Suitable solid carriers include natural and synthetic clays and silicates, for example natural silicas such as distomaceous earths; magnesium silicates, for example talcs; magnesium aluminium silicates, for example attapulgites and vermiculites; aluminium silicates, for example kaolinites, montomorillonites and micas; calcium carbonate; calcium sulphate; ammonium sulphate; synthetic hydrated silicon oxides and synthetic calcium or aluminium silicates; elements, for example carbon and sulphur; natural and synthetic resins, for example coumarone resins, polyvinyl chloride, and styrene polymers and copolymers; solid polychlorcphenols; bitumen; waxes; and solid fertilisers, for example soFxrFbosçbates. The term 1carrier" as used herein neans an inert solid or fluid material, which may be inorganic or organic and of synthetic or natural origin, with which the active compound is mixed or formulated to faclitate its application to the plant, seed, soil or other object to be treated, or its storage, transport and/or handling. Any of the materials customarily employed in formulating pesticides, herbicides, or fungicides, are suitable. Suitable solid carriers are natural and synthetic clays and silicates, for example, natural silicas such as diatomaceous earths; magnesium silicates, for example, talcs; magnesium aluminum silicates, for example, kaolinites, montmorillonites and micas; calcium carbonate; calcium sulfate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; elements such as, for example, carbon and sulfur; natural and synthetic resins such as, for example, coumarone resins, polyvinyl chloride and styrene polymers and copolymers; bitumen ; waxes such as, for example, beeswax, paraffin wax, and chlorinated mineral waxes; solid fertilizers, for example, superphosphates ; and ground, naturally-occurring, fibrous materials, such as ground cornnnas. Examples of suitable fluid carriers are water, alcohols such as, for example, isopropyl alcohol, glycols; ketones such as, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone ; ethers such as, for example, cellosolves; aromatic hydrocarbons such as, for example, kerosene, light mineral oils; chlorinated hydrcarbons such as, for example, carbon tetrachloride, perchloroethylene, trichloroethane, including liquefied, normally vaporous, gaseous compounds, Mixtures of different liquids are often suitable. The surface-active agent may be an emulsifying agent, a dispersing agent or a wetting agent; it may be nonionic or ionic. Examples of suitable surface-active agents include the sodium or calcium Salts of polyacrylic acids and lignin sulponic acids; the condensation of fatty acids or aliphatic ermines or amides containing at least 12 carbon atoms in the molecule with ethylene oxide and/or propylene oxide: fatty acid esters of glycerol, sorbitan, sucrose or pentaerythritol ; condensates of these with ethylene oxide and/or propylene oxide; condensation products of fatty alcohol or alkyl phenols, for example p-octylphenol or p-octyloresol, with ethylene oxide and/or propylene oxide; sulphates or sulphonates of these condensation products; alkali or alkaline earth metal salts, preferably sodium salts, of sulphuric or sulphonic acid esters containing at least 10 carbon atoms in the molecule, for example sodium lauryl sulphate, sodium secondary alkyl sulphates, sodium salts of sulphonated castor oil, and sodium alkylaryl sulphonates such as dodecylbenzene sulphorate ; and polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide. The catpositions of the invention may for example be formulated as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emLlsicns, suspension concentrates and aerosols. Wettable powders usually cantain 25, 50 or 75% w of active ingredient and usually contain in addition to solid inert carrier, 3-10% w of a dispersing agent and, where necessary, 0-10% w of stabiliser(s) and/or other additives such as penetrants or stickers. Dusts are usually formulated as a dust concentrate having a similar composition to that of a wettable powder but without a dispersant, and are diluted in the field with further solid carrier to give a composition usually containing h-10% w of active ingredient. Granules are usually prepared to have a size between 10 and 100 BS mesh (1.676 0.152 mm), and may be manufactured by agglomeration or impregnation techniques. Generally, granules will contain w w active ingredient and 0-10% w of additives such as stabilisers, surfactants, slow release modifiers and binding agents. Emulsifiable concentrates usually contain, in addition to a solvent and, when necessary, co-solvent, 10-50% weight per volute active ingredient, 2-20% weight per volume emulsifiers and 0-20% weight per volume of other additives such as stabilisers, penetrants and corrosion inhibitors. Suspension concentrates are usually confounded so as to abstain a stable, non-sedimenting flawable product and usually contain 10-75% w active ingredient, 0.5-15% w of dispersing agents, 0.1-108 w of suspending agents such as protective colloids and thixotropic agents, 0-10% w of other additives such as defoamers, corrosion inhibitors, stabilisers, penetrants and stickers, and water or an organic liquid in which the active ingredient is substantially insoluble; certain organic solids or inorganic salts may be present dissolved in the formulation to assist in preventing sedimentation or as anti-freeze agents for water. Aqueous dispersions and emulsions, for example compositions obtained by diluting a wettable powder or a concentrate according to the invention with water, also lie within the scope of the invention. The said emulsions may be of the water-in-oil or of the oil-in-water type, and may have a thick 'mayonnaise' - like consistency. The Composition of the invention may also contain other ingredients, for example other comçounds possessing berbicidal, insecticidal or fungicidal properties, as are appropriate to the intended purpose. Protection of a locus or area fran undesirable plants is effected by applying a compound of Formula I, ordinarily in a composition of one of the aforementioned types, to soil in which the seeds of the unwanted plants are present, or to the foliage of the unwanted plants. The active compound, of course, is applied in an amount sufficient to exert the desired action. The amount of the carpound of the invention to be used in combating undesired plants will naturally depend on the condition of the plants, the degree of activity desired, the formulation used, the mode of application, the climate, the season of the year, and other variables. Recommendations as to precise amounts are, therefore, not possible. In general, however, application to the locus to be protected of fram 0.1 to 10.0 kg per hectare of the compound of Formula I will be satisfactory. The preparation, isolation and physical properties of typical individual species of the compounds of Formula I, in particular instances, are described in the following examples. In each case, the identity of the product, and each of any intermediate involved, was confirrred by appropriate chemical and spectral analyses. Example 1-1Methyl-3-(5-(tertiary-butyl)-1,2-oxazol-3-yl) imidazolidinetrione (1) A solution of 41.5g of hydroxylamine hydrochloride in 136 ml of water was added drcp-by-drop over a 10-minute period to a stirred, reflexing mixture of 56.1 g of pivaloylacetonitrile (British patent 2,014,992), 700 ml of water and 525 ml of ethanol. The mixture was held under those conditions for 7 hours, the pH of the mixture being periodically adjusted to 6.5 by the addition of either hydrogen chloride or aqueous sodium hydroxide solution, as required. Then the solvent ethanol was evaporated in a rotary evaporator, and the residual liquid was dried (EgSO4), placed in 200 ml of hexane and chilled. Filtration and fractional crystallizaticn of the solid gave 3-amino-5-(tartiary-butyl)-1,2-oxazole (1A), a yellow solid, m.p.: 107-109 C. A second fraction was 5-aino-3-(tertiary- butyl)-1,2-oxazole (1B), a solid, m.p.: 89-900C. 1A was converted to 1-methyl-3-(5- (terti;lrv-butvl)-l,2- oxazol-3-yl)urea (1C) by the method and procedures disclosed in U.S. patent No. 4,062,861. 3.6g of oaalyl chloride was added to a solution of 5.0g of 1C in 250 ml of toluene. The solution was refluxed for 15 minutes, then the solvent was evaporated under reduced pressure. The residue was crystallized fran ether-hexane to give 1, a colorless solid, m.p. : 127-1280C. Example 2 - 1-Methyl-3-(3-tertiary-butyl)-1,2-oxadiazol-5-yl)- -imidazolidinetrione (2) A mixture of 2g of 1B, 3g of methyl isocyanate and 10 ml of tetrahydrofuran containing 0.1 ml of triethylamine was stirred and refluxed for 22 hours. Then it was cooled to 200C, filtered, and washed with cold ether. Recrystallization from ether gave 1-methyl-3-(3-(tertiaryQbutyl)-1,2-cxazol-5-yl)urea (2A), as a white solid, m.p.: 198-1990C. 2 was prepared as a solid, m.p.: 176-1790C, frcm 2A and oxalyl chloride by the method described in Example 1 for ccrwerting 1C to 1. Example 3 - 1-Methyl-3-(5-(1-methylcyolopropyl)-1,2-oxazol-3 yl)-imidazolidinetrione (3) A mixture of 61.lg of acetonitrile and 108.3g of methyl 1-methylcyclopropanecarboxylate was added drop-by-drop over a one-hour period to a stirred, refluxing mixture of 35.8g of sodium hydride and 650 ml of tetrahydrofuran. The resulting mixture was stirred and refluxed for a further 18 hours, then most of the solvent was evaporated in a rotary evaporator. The residue was dissolved in 1 liter of water, and the solution was acidified with hydrochloric acid and extracted with ether. The extract was dried (MgSO4) and concentrated. The residue, a liquid, was fractionally distilled to give (1-methylcyclopro- pylcarbayl)acetonitrile (3A) as a colorless oil which crystallized on standing, m.p.: 32-330C. 3A was converted to 3-amino-5-(1-methylcyclopropyl)-1,2oxazole (3B), a white solid m.p.: 82-840C, and 5-amino-3-(1methylcyclopropyl)-1,2-oxazole (3C), a white solid, m.p.: 106-1090C, by the method described for the preparation of 1A and 1B, Example 1. A solution of 1.0g of 3B and 0.6g of methyl isocyanate in ismI of ether containing one drop of triethylamine was held at 220C for 18 hours. Then the mixture was cooled to-10 C and filtered, giving 1-methyl-3-(5-(1-methyloyolopropyl)-1,2-oxazol 3-y1)urea (3D), as a colorless solid, m.p.: 144-1470C. 3D was converted to 3, as a colorless solid, m.p.: 124-1260C, by the method described in Example 1 for converting 1C to 1. Exarrple 4 - 1-Methyl-3-(3-(1-methylcyclopropyl)-1,2-oxazol-5- yl) -innidazolidinetrione (4) A solution of l.Og of 3C and 0.6g of methyl isocyanate in 15 ml of ether containing one drop of triethylamine was held at 22 C for 24 hours. No reaction took place. The mixture was placed in a sealed glass cylinder and heated for 24 hours on a steam bath. Then the solvent was evaporated and the residue was chromatographed over silica gel using as eluent Solvent No. 3 (a 2:15:33 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane), to give 3-bis(methylaminocarbonylamino)-3-(1-methylcyclopropyl)-1,2-oxazole (4A), as a white solid, m.p.: 125-1270C. 4A was converted to 4, as an off-white solid, m.p.: 125-1270C, by the method described in Example 1 for converting 1C to 1. Example 5 - 1-methyl-3-(5-(1-methoxymethyl)-1-methylethyl)-1,2- oxazol-3-yl) imidazolidinetrione (5) 219g of chlonpivaloyl chloride was added drop-by-drop to a chilled (0-50C), stirred solution of 141.4g of triethylamine in 320g of anhydrous methanol. The resulting mixture was warned to room temperature in one hour, and most of the methanol was evaporated under reduced pressure. The residue was drowned in water and extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated. The residue was distilled to give methyl 3-chloro-2,2-dimethylpropionate (5A), b.p.: 40-500C (14 Torr.). A solution of 168.3g of 5A in 76g of acetonitrile and 118 ml of tetrahydrofuran was added drop-by-drop over a one-hour period to a stirred, refluxing mixture of 42.2g of sodium hydride and 766 ml of tetrahydrofuran. The resulting mixture was stirred and refluxed for 18 hours, then part of the solvent was evaporated. The residue was drowned in 1 liter of ice water, the resulting mixture was acidified with hydrochloric acid and extracted with ether. The extract was dried (MgSO4), concentrated and distilled to give ((1-(methoxymethyl)-1-methyl- ethyl)carbonyl)acetonitrile (SB), as a oolorless liquid, b.p.: 86-90 C (0,2 Torr.). A solution of 58.5g of hydroxylamine hydrochloride in 88 ml of water was added drop-by-drop over a 10-minute period to a stirred, reflexing solution of 100.9g of 5B and 33.7g of sodium hydroxide in 950 ml of water and 740 ml of ethanol. The mixture was stirred and refluxed for a further 18 hours, then the ethanol was evaporated on a rotary evorator. The a aqueous residue was cooled and filtered. The solid was chromatographed over silica gel, using Solvent No. 3 as eluent, to give 3-amino-5-(1-(methoxymethyl)-1-methylethyl)-1,2-oxazole (5C), as a cream-colored solid, m.p.: 61-640C. SC was converted to 1-methyl-3-(5-(1-(methoxymethyl)-1- methylethyl) -1,2-oxazol-3yl) urea (SD), as a solid, m.p.: 113-1150C, by the procedures described in Example 3 for converting 3B to 3D. 5D was converted to 5, a solid, m.p.: 93-940C, by the method described in Example 1 for converting 1C to 1. Example 6 - 1-methyl-3-(5-(1,1-dimethyl-2-propyn-1-yl)-1,2- oxazol-3-yl)imidazolidinetrione (6). The methyl ester of 2,2-dimethyl-3-butynoic acid (6A) was prepared fran the acid (M.A. Sehexnayder and P.S. Engel, Journal of the American Chemical Society, Vol. 97, pp 4825 et seq. (1975)) by conventional procedures. A mixture of 109.8g of 6A and 56.2g of acetonitrile was added drop-by-drop to a stirred, refluxing mixture of 72.5g of sodium hydride and 650 ml of tetrahydrofuran. The mixture was stirred and refluxed for 2 hours, then cooled to 20 C and stirred for 18 hours. Then the solvent was evaporated in a rotary evaporator, the residue was drowned in 500 ml of ether, and water was added cautiously. The resulting aqueous phase was separated, acidified with hydrachloric acid and extracted with ether. The extract was dried (M8S041 and the solvent was evaporated. The residue, a dark viscous syrupy was distilled to give ((1, 1-dimethyl-2-propyn-1-yl)carbonyl)acetonitrile (6B), a yellow liquid, b.p.: 65-670C (0.5 Torr.). Over a 15-minute period, 21.0g of 6B was added to a solution of 9.lg of sodium hydroxide in 240 ml of water and 200 ml of ethanol at roan temperature. The pH of the mixture was adjusted to 6.4-6.6. The mixture was stirred, heated to 900C and stirred at that temperature for 8 hours. The ethanol was evaporated under reduced pressure and the aqueous residue was extracted with ether. The extract was dried (MgS04) and concentrated. The resulting amber syrup was chraratographed oeer silica gel, using Solvent No. 3 as eluent, to give 3-amuno-5- (1,1-dimethyl-2-propyn-1-yl)-1,2-oxazole (6C), as an off-white solid, m.p.: 98-100 C. 8.0g of 6C was treated with methyl isocyanate by the rrethod described for treatment of 3C in Example 4, to give 3-bis (- methylaminocarbonylamino)-5-(1,1-dimethyl-2-propyn-1-yl)-1,2-oxazole (6D), as a light amber syrup. A mixture of 5.4g of 6D, 1.2g of sodium hydroxide, 10 ml of water and 50 ml of tetrahydrofuran was stirred and refluxed for 6 hours. Then it was concentrated under reduced pressure, the residue was diluted with 50 ml of water, acidified with dilute hydrochloric acid and extracted with methylene chloride. The extract was dried (M9S04), filtered and concentrated. The residue was recrystallized fran ether-hexane to give 1-methyl-3- (5-(1,1-dimethyl-2-propyn-1-yl)-1,2-oxazol-3-yl)urea (6E), as a cream-colored solid, m.p.: 117-120 C. 6E was treated with oxalyl chloride, by the method described for treatment of 1C, Example 1, to give 6, as a tan solid, m.p.: 99-1010C. Example 7 - 4-Methyl-2-((5-tertiary-butyl)-1,2-oxazol-3-yl)- 1,2,4-thiadiazolidine-3,5-dione (7X) ; 2-Metyl-4 ((5-tertiaryl-butyl)-1,2-oxazol-3-yl)-1,2,4-thia diazolidine-3,5-dione (7Y) A solution of 41.5g of hydroxylamine hydrochloride in 136 ml of water was added drop-by-drop over a 10-minute period to a stirred, refluxing mixture of 56.lg of pivaloylacetonitrile (British patent 2,014,992), 700 ml of water and 525 ml of ethanol. The mixture was held under those conditions for 7 hours, the pH of the mixture being periodically adjusted to 6.5 by the addition of either hydrogen chloride or aqueous sodium hydroxide solution, as required. Then the solvent ethanol was evaporated in a rosary evaporator, the residual liquid was dried and placed in 200 ml of hexane and chilled. Filtration and fractional crystallization of the solid gave 3-emino-5- (tertiary-butyl)-1,2-oxazole (7A), a yellow solid, m.p.: 107-1090C. A second fraction was 5-amino-3-(tertiaryQbutyl)- 1,2-oxazole (7B), a solid, m.p. 89-900C. 7A was converted to 1-methyl-3-(5-(tertiary-butyl)-1,2- oxazol-3-yI)urea (7C) by the method and procedures disclosed in U.S. patent No. 4,062,861. 40.8g of (chlorothio)formyl chloride was added to a stirred solution of 50.0g of 7C in 800 ml of methylene chloride at roan temperature. The resulting solution was cooled and held at 10-150C while 80.6g of ethyldiisopropylamine was added drcp-by-drap in two hours. The resulting fixture was stirred for 16 hours at room temperature, then mixed with water and extracted with methylene chloride. The extract was dried (MgSO4), the solvent was evaporated, and the residue was absorbed on silica gel and eluted with a 1:4:20 v:v:v mixture of tetrahydrofuran, methyl acetate and hexane. The fi first fraction that was obtained consisted of the starting urea. Upon recrystallization from ether-hexane, the second fraction gave 7X, an off-white solid, m.p.: 113-1140C. The third fraction was 7Y, a light yellow solid, m.p.: 114-1150C. The melting point of a mixture of 7X and n was depressed (92-950C). Example 8 - 4-Methyl-((5-(1,1-dimethyl-2-methoxyethyl)-1,2- axazol-3yl) -1,2,4-thiadiazolidirae-3,5-dione (8) 219g of chloropivaloyl chloride was added drop-by-drop to a chilled (O-50C), stirred solution of 141. 4g of triethylamine in 320g of anhdrous methanol. The resulting mixture was wormed to roam temperature in one hour, and most of the methanol was evaporated under reduced pressure. The residue was mixed with water and extracted with ether. The extract was dried (MgSO4), and the solvent was evaporated. The residue was distilled to give methyl 3-chloro-2,2-dimethylpropionate (8A), b.p.: 40-500C (14 Torr.). A solution of 168.3g of 8A in 76g of acetonitrile and 118 ml of tetrahydrofuran was added drop-by-drop over a one-hour period to a stirred, refluxing mixture of 42.2g of sodium hydride and 766 ml of tetrahydrofuran. The resulting mixture was stirred and refluxed for 18 hours, then part of the solvent was evaporated. The residue was added to 1 liter of ice water, and the resulting mixture was acidified with hydrochloric acid and extracted with ether. The extract was dried (MgS04) and distilled to give ((1-(methoxymethyl)-1-methylethyl)carbonyl)- acetonitrile (8B), as a colorless liquid, b.p. : 86-90 C (0.2 Torr.). A solution of 58.5g of hydroxylamine hydrochloride in 88 ml of water was added drcp-by-drop over a 10-minute period to a stirred, refluxing solution of 1OO.9g of 8B and 33.7g of sodium hydroxide in 950 ml of water and 740 ml of ethanol. The mixture was stirred and refluxed for 18 hours, then the ethanol was evaporated in a rotary evaporator. The aqueous residue was cooled and filtered. The solid was chronatographed over silica gel, using a 2:15:33 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent, to give 3-amino-5-(1-(methoxy rrrethyl) -linethylethyl)-1,2-oxazole (8C), as a cream-colored solid, m.p.: 61-640C. A solution of 1.0g of 8C and 1.0g of methyl isocyanate in 15 ml of anhydrous ether was held at roan temperature for 3 days. Then the solvent was evaporated and the residue was crystallized fran hexane to give 1-methyl-3-(5-(1,1-dimethyl- 2-methoxyethyl)-1,2-oxazol-3-yl)urea (8D), as a colorless solid, m.p.: 113-1150C. 10.0g of 8D was treated with (chlorothio)formyl chloride and ethyldiisopropylamine by the procedure described in Example 7, to give 8, as a light yellow solid, m.p.: 65-670C. Example 9 - 1-Methyl-3-(5-(tertiary-butyl)-1,2-oxazol-3-yl)-5- hydroxyimidazolidine-2,4-dione (9X) ; 3-Methyl-1-(5 (tertiary-butyl)-1,2-oxazol-3-yl)-5-hydroxyimidar olidine-2,4-dione (9Y) A solution of 41.5g of hydroxylamine hydrochloride in 136 ml of water was added drop-by-drop over a 10-minute period to a stirred, refluxing mixture of 56.lg of pivaloylacetonitrile (British patent 2,014,992), 700 ml of water and 525 ml of ethanol. abe mixture was held under those conditions for 7 hours, the pH of the mixture being periodically adjusted to 6.5 by the addition of either hydrogen chloride or aqueous sodium hydroxide solution, as required. Then the solvent ethanol was evaporated in a rotary evaporator, and the residual liquid was dried (MgSO4), , placed in 200 ml of hexane and chilled. Filtration and fractional crystallization of the solid gave 3-amino-5-(tertiary-butyl)-1,2-oxazole (9A), a yellow solid, m.p.: 107-1090C. A send fraction was 5-amino-3-(tertiary- butyl)-1,2-oxazole (9B), a solid, m.p.: 89-900C. 9A was converted to 1-methyl-3-(5-tertiary-butyl-1,2 oaLLzol-3-yl)urea (9C) by the method and procedures disclosed in U.S. patent No. 4,062,861. 6.4g of glyoxylic acid hydrate was added to a stirred solution of 10.0g of 9C in 300 ml of methylene chloride at roan temperature. The solution was refluxed for one hour, then the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel, using a 1:4:20 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent. The first fraction was a solid, which on recrystallization from ether-hexane gave 9Y, as a colorless solid, m.p.: 128-130 C. The second fraction was 9X, a light yellow syrup, which on standing crystallized, m.p.: 122-1230C. Example 10 - 1-Methyl-3-(5-(1-methylcyclopropyl)-1,2-oxazol-3- yl) -5-hydraxyimidazolidine-2 ,Q-dione (lOX); 3-Methyl-1-(5-(1-methylcyclopropyl)-1,2-oxazol-3 yl)-5-hydoxyimidazolidine-2,4-dione (10Y) A mixture of 61.1g of acetonitrile and 108.3g of methyl 1-methylcyclopropanecarboxylate was added drop-by-drop over a one-hour period to a stirred, refluxing mixture of 35.8g of sodium hydride and 650 ini of tetrahydrofuran. The resulting mixture was stirred and refluxed for a further 18 hours, then itost of the solvent was evaporated in a rotary evaporator. The residue was dissolved in 1 liter of water, and the solution was acidified with hydrochloric acid and extracted with ether. The extract was dried (MgSO4) and concentrated. The residue, a liquid, was fractionally distilled (69-710C (4.5 Torr.) to give (1-methyl-cyclopropylcarbonyl)acetonitrile (10A) as a colorless oil which crystallized on standing, m.p.: 32-330C. 10A was converted to 3-amino-5-(1-methylcyclopropyl)-1,2- oxazole (10B), a white solid m.p.: 82-840C, and 5-am}no-3-(1- methyl-cyclopropyl)-1,2-oxazole (10C), a white solid, m.p. : 106-1090C, by the method described for the preparation of 9A and 9B, Example 9. A solution of 1.0g of 10B and 0.6g of methyl isocyanate in 15 ml of ether containing one drop of triethylamine was held at 22 C for 18 hours. Then the mixture was cooled to -100C and filtered, giving 1-methyl-3-(5-(1-methylcyclopropyl)-1,2-oxazol3-yl)urea (10D), as a colorless solid, m.p.: 144-147 C. 4.6g of glyoxylic acid hydrate was added to a stirred solution of 2.0g of lOD in 200 ml of xylene. The resulting solution was reflexed for 30 minutes, then the solvent was evaporated under reduced pressure. The residue was chromatographed over silica gel, using Solvent No. 3 (a 2:15:33 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane) as eluent. Workup and recrystallization from methanol gave 10X as a first fraction, as a colorless solid, m.p. 160-1630C. The second fraction was 10?, as a colorless solid, m.p.: 146-1490C. Example 11 - 1-methyl-3-(5-(1,1-dimethyl-2-propyn-1-yl-1,2- oxazol-3-yl)-5-hydroxyimidazolidine-2,4-dione (11X) ; 3-Methyl-1-(5-(1,1-dimethyl-2-propyn-1-yl)-1,2 oxazol-3-yl)-5-hydroxyimidazolidine-2,4-dione (11Y) The methyl ester of 2,2-dimethyl-3-butynoic acid (11A) was prepared from the acid (M.A. Schexnayder and P.S. Engel, Journal of the America Chemical Society, Vol. 97, pp 4825 et seq. (1975)) by conventional procedures. A mixture of 109.8g of IlA and 56.2g of a acetonitrile was added drop-by-drop to a stirred, refluxing mixture of 72.5g of sodium hydride and 650 rnl of tetrahydrofuran. The mixture was stirred and refluxed for 2 hours, then cooled to 20 C and stirred for 18 hours. Then the solvent was evaporated in a rotary evaporator, the residue was drowned in 500 rnl of ether, and water was added cautiously. The resulting aqueous phase was separated, acidified with hdyrschloric acid and extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated. The residue, a dark viscous syrup, was distilled to give ((1,1-dimethyl-2-propyn-1-yl)carbonyl)acetonitrile (11B), a yellow liquid, b.p.: 65-670C (0.5 Torr.). Over a 15-minute period, 21.0g of 11B was added to a solution of 9.1g of sodium hydroxide in 240 ml of water and 200 ml of ethanol at roman teperature. The pH of the mixture was adjusted to 6.4-6.6. The mixture was stirred, heated to 900C and stirred at that temperature for 8 hours. The ethanol was evaporated under reduced pressure and the aqueous residue was extracted with ether. The extract was dried (MgSO4) and concentrated. me resulting amber syrup was chromatographed over silica gel, using as eluent Solvent No. 3, to give 3-armino-5- (l,l-dimethyl-2-propyn-lyl) -1,2-oxazole (llC), as an off-white solid, m.p.: 98-1000C. 8.0g of 11C was treated with methyl isocyanate by the method described for treatment of 10B in Example 10, to give 3-bis(methylaminocarbonylamino)-5-(1,1-dimethyl-2-propyn-1-yl) 1,2-axazole (11D), as a light amber syrup. A mixture of 5.4g of 11D, 1.2g of sodium hydroxide, 10 ini of water and 50 ml of tetrahydrofuran was stirred and refluxed for 6 hours. Then it was concentrated under reduced pressure, the residue was diluted with 50 ml of water, acidifed with dilute hydrochloric acid and extracted with methylene chloride. The extract was dried (MgS04), filtered and concentrated. The residue was recrystallized fran ether-hexane to give 1-methyl 3-(5-(1,1-dimethy1-2-propyn-1-yl)-1,2-oxazol-3-y1)urea (llE), as a cream colored solid, m.p.: 117-1200C. A mixture of 5.7g of 11E, 250 ml of toluene and 7.0g of glyoxylic acid hydrate was heated for two hours. The solvent was evaporated and the residue was chromatographed over silica gel, using Solvent No. 3 as eluent. Two fractions, each consisting of an aeber syrup, were obtained. The first fraction was identified as 11Y; the second fraction was identified as 11X. Example 12 - 3,5-Dimethyl-1-(5-(tertiary-butyl)-1,2-oxazol-3- yl) hexahydro-1,3,5-triazine-2-ane (12) A solution of 41.5g of hydroxylamine hydrochloride in 136 ml of water was added drop-by-drop over a 10-minute period to a stirred, refluxing mixture of 56.lg of pivaloylacetonitrile (British patent 2,014,992), 700 ml of water and 525 ml of ethanol. The mixture was held under those conditions for 7 hours, the pH of the mixture being periodically adjusted to 6.5 by the addition of either hydrogen chloride or aqueous sodium hydroxide solution, as required. Then the solvent ethanol was evaporated in a rotary evaporator, and the residual liquid was dried (MgSO4), placed in 200 ml of hexane and chilled. Filtration and fractional crystallization of the solid gave 3-amino-5-(tartiary-butyl)-1,2-oxazole (12A), a yellow solid, m.p. : 107-109 C. 12A was converted to 1-methyl-3-(5-(tertiary-butyl)-1,2 oxazol-3-yl)urea (12C) by the method and procedures disclosed in U.S. patent No. 4,062,861. 24 ml of a 36% aqueous formaldehyde solution was added drop-by-drop to a stimied solution of 15.0g of 12C in 75 ml of dimethylfonmamide. The resulting mixture was stirred for 30 minutes, then 12 ml of a 40% aqizus methylamine solution was added drop-by-drop, the temperature of the mixture being held below 35 C. The resulting solution was stirred at roan temperature for 30 minutes, then on a hot water bath for 4 hours, then the solvent was evaporated under reduced pressure. The residue was a colorless syrup that crystallized upon stranding. Recrystallization from hexane gave 12, as a colorless solid, m.p. : 100-102 C. Example 13 3,5-dimethyl-1-(5-(1-(methoxymethyl]-1-methylethyl) 1,2-oxazol-3-yl)hexahydro-1,3-5-triazin-2-one (13) 219g of chloropivaloyl chloride was added drop-by-drop to a chilled (0-5 C), stirred solution of 141.4g of triethylamine in 320g of anhydrous methanol. The resulting mixture was warned to roam temperature in one hour, and most of the methanol was evaporated under reduced pressure. The residue was drowned in water and extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated. The residue was distilled to give methyl 3-chloro-2,2-dimethylpropionate (13A), b.p.: 40-50 C (14 Torr.). A solution of 168.3g of 13A in 76g of acetonitrile and 118 ml of tetrahydrofuran was added drop-by-drop over a one-hour period to a stirred, refluxing mixture of 42.2g of sodium hydride and 766 ml of tetrahydrofuran. The e resulting mixture was stirred and refluxed for 18 hours, then part of the solvent was evaporated. The residue was drowned in 1 liter of ice water, and the resulting mixture was acidified with hydrochloric acid and extracted with ether. The extract was dried (MgSO4), concentrated and distilled to give ((1- (methoxymethyl) methyl ethyl)carbonyl)acetonitrile (13B), as a colorless liquid, b.p. : 89-900C (0.2 Tbrr.). A solution of 58.5g of hydroxylamine hydrochloride in 88 ml of water was added drop-by-drop over a 10-minute period to a stirred, refluxing solution of 100.9g of 13B and 33.7g of sodium hydroxide in 950 ml of water and 740 ml of ethanol. The mixture was stirred and refluxed for a further 18 hours, then the ethanol was evaporated in a rotary evaporator. The aqueous residue was cooled and filtered. The solid was chromatographed over silica gel, using as eluent a 2:15:33 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane, to give 3-amino-5- (1-(methoxymethyl)-1-methylethyl)-1,2-oxazole (13C), as a oream-colored solid, m.p.: 96-990C. 13C was converted to 1-methyl-3-(5-(1-(methoxymethyl)-1- methylethyl)-1,2-oxazol-3-yl)urea (13D), as a solid, m.p.: 113-1150C, by the procedures described in U.S. patent No. 4,062,861. 16 ml of a 36% aqueous formaldehyde solution was added dropwise to a stirred solution of 4.1g of 13D in 75 ml of dimethylformamide. The temperature of the mixture rose from 220C to 270C. The mixture was stirred for 30 minutes, then 8 ml of a 40% solution of methylamine in water was added, drop-by-drop. The temperature of the mixture rose fran 270C to 360C. The mixture was refluxed for 3 hours, then the solvent was evaporated under reduced pressure. The residue was mixed with cold water, and the resulting mixture was extracted with ether. The solvent was evaporated from the extract, and the residue was crystallized when hexane was added, to give 13, as a white solid, m.p.: 49-50 C. Example 14 - 3,5-Dimethyl-1-(5-(1,1-dimethyl-2-propynyl)-1,2- oxazol-3-yl)-hexahydro-1,3,5-triazin-2-one (14) The methyl ester of 2, 2iirthyl-3-butynoic acid (14A) was prepared from the acid (M.A. Schexnayder and P.S. Angel, Journal of the Americal Chemical Society, Vol. 97, pp 4825 et seq. (1975)) by conventional procedures. A mixture of 109.8g of 14A and 56.2g of acetonitrile was added drop-by-drop to a stirred, refluxing mixture of 72.5g of sodium hydride and 650ml of tetrahydrofuran. The mixture was stirred and refluxed for 2 hours, then cooled to 200C and stirred for 18 hours. Then the solvent was evaporated in a rotary evaporator, the residue was drowned in 500 ml of ether, and water was added cautiously. The e resulting aqueous phase was separated, acidified with hydrochloric acid and extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated. The e residue, a dark viscous syrup, was distilled to give ((1,1-dimethyl-2-prpyn-1-yl)carbonyl)acetonitrile (14B), a yellow liquid, b.p. : 65-67 C (0.5 Torr.). Over a 15-minute period, 21.0g of 14B was added to a solution of 9.1g of sodium hydroxide in 240 ml of water and 200 ml of ethanol at roan temperature. The pH of the was adjusted to 6.4-6.6. The mixture was stirred, heated to 900C and stirred at that temperature for 8 hours. The ethanol was evaporated under reduced pressure and the aqueous residue was extracted with ether. The extract was dried (MgS04) and concentrated. The resulting amber syrup was chromatographed over silica gel, using Solvent No. 3 as eluent, to give 3-amino-5- (1, l-dirrethy-2-prapyn-lyl)-1,2-oxazole (14C), as an off-white solid, m.p.: 98-1000C. A solution of 7.5g of 14C and 5 ml of methyl isocyanate in 50 ml of tetrahydrofuran was heated at 50-60 C for two days. The solvent was evaporated under reduced pressure and the residue was chromatographed over silica gel, using as eluent a 1:4:20 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane, to give 1-methyl-3-(5-(1,1-dimethyl-2-propyn-1-yl)-1,2 -oxazol-3-yl)urea (14D), as a white crystalline solid, m.p.: 99-1000C. 3 ml of a 36% aqueous formaldehyde solution was added drop-by-drop to a stirred solution of 1.0g of 14D in 25 ml of dimethylformamide, at roan temperature. After 30 minutes of stirring, 1.5 ml of 40% aqueous methylamine solution was added drop-by-drop, to the mixture. The resulting mixture was stirred for 30 minutes at roam temperature and then on a water bath for one hour, then was held at room temperature for 18 hours. The solvents were evaporated under reduced pressure in a rotary evaporator. The residue was chromatographed over silica gel, using as eluent a 2:15:13 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane, to give 14, as a colorless solid, m.p.: 85-87 C, upon recrystallization from ether. Example 15 - 5-methyl-3irr?thoLxy-1- (5- (tertiary-butyl) -1,2- oxazol-3-yl)hexahydro-1,3,5-triazin-2-one (15) 99g of phosgene was bubbled into 500 ml of ethyl acetate, then a solution of 71.6g of 12A in 400 ml of ethyl a acetate was added drop-by-drop to the stirred mixture. The mixture was stirred at reflux temperature for five hours, left standing overnight at roam temperature, and filtered. The solid was dried at roan temperature for two days ys to give dimeric 3-isocyanato-5-(tertiary-butyl)-1,2-oxazole (15A),m.p. : 165-1670C. 8.5g of methoxyamine was added very slowly to a stirred solution of 15g of 15A in 600 ml of tetrahydrofuran. The resulting mixture was filtered and the solid was triturated with ether to give 1-methoxy-3-(5-(tertiary-butyl)-1,2-oxazol-3-yl)- urea (15B), m.p.: 145-148 C. By the procedure described in the last paragraph of Example 12, 15B was converted to 15, which was isolated as a solid, m.p.: 90-920C, by chromatographing the crude reaction product over silica gel, using a 1:1:2 v:v:v mixture of tetrahydrofuran, ethyl acetate and hexane as eluent, 15 being the first fraction collected. Example 16 - 3-Methyl-5-(5-(tertiary-butyl)-1,2-oxazol-3-yl)-2,6 -dihydro-l ,3,5-axadiazin--ane (16) A mixture of 5.0g of 12C, 0.75g of paraformaldehyde, 1.3g of para-toluenesulfonic acid, 0.51g of dimethylformamide and 150 ml of toluene was stirred at 80 C for 15 minutes. The resulting mixture was poured into 200 ml of water and phase-separated. The toluene phase was dried (MgSO4), filtered and concentrated in a rotary evaporator. The residue was triturated with hexane, and the liquid was chromatographed over silica gel, using a 20:4:1 v:v:v mixture of hexane, ethyl acetate and tetrahydrofuran as eluent. Workup gave 16, as a colorless syrupy liquid. Example 17 - Herbicidal Activity In the following trials, the species of plants that were tested were: Barnyardgrass (watergrass) - Enchinochloa crus-galli Large crabgrass - Digitaria sanguinalis Downy brome - Brooms tectorum Yellow foxtail - Setaria lutescens Redroot pigweed - Amaranthus retroflexus Sicklepod - Cassia obtusifolia Velvetleaf - Abutilon theophrasti Garden cress - Lepidium sativum Johnsongrass - Sorghum halepense Test Procedures The preemergence (soil) berbicidal activity of the compounds was evaluated by planting seeds of barnyardgrass, garden cress, downy brare, velvetleaf, yellow foxtail, and sicklepod in test tubes, nominally measuring 25 x 200 millimeters, filled about three-quarters full of untreated soil, in each case covered on top with about 2.5 cubic centimeters of soil treated with a certain amount of the test compound. The treated soil applied to the tubes containing the barryardgrass and cress seeds contained one milligram of the test compound per tube, and contained 0.1 milligram of the test carpound per each tube containing the seeds of the other plants. The dosages were approximately 20 and 2.0 kg. of test compound per hectare, respectively. The seeds were planted on top of the treated soil and covered with about 1.5 cubic centimeters of untreated soil. planted soil was held under controlled conditions of temperature, moisture, and light for 9 to 10 days. The amounts of germination and growth in each tube were evaluated on a O to 9 scale, the nueric ratings having the following meanings: : Rating Meaning 9 No living tissue 8 Plant severely damaged and expected to die 7 Plant badly damaged, but expected to live 6 Moderate damage, but complete recovery expected 5 Intermediate damage (probably unacceptable for crop plants) 3-4 Observable damage 1-2 Plant slightly affected, possibly by the chemical, possibly due to biological variability O Nb visible effect The postamergence (foliar) herbicidal activity of compounds of the invention was evaluation by spraying 10-day-old large downy brome plants in some cases, 6-day-old Johnsongrass plants in other cases, 9-day-old velvetleaf plants, 9-day-old yellow foxtail plants and 9-day-old sicklepod plants to runoff with a liquid formulation of the test compound. The crabgrass and pigweed plants were sprayed with 2.4 milliliters of a 0.25% solution (about ten kg. of the test compound per hectare), and other plants were sprayed with 2.4 milliliters of a 0.025% solution (about one kg. of the test compound per hectare). The sprayed plants were held under controlled conditions of temperature, moisture and light for 7 to 8 days, and the effect of the test compound was then evaluated visually, the results being rated on the O to 9 scale described above. Results of the preemergence and postemergence herbicidal activity tests are set forth in Table I. TABLE I - HERBICIDAL ACTIVITY EMI32.1 <SEP> Preemergence <SEP> Postemergence <tb> <SEP> Barnyard- <SEP> Garden <SEP> Downy <SEP> Velvet- <SEP> Yellow <SEP> Sickle- <SEP> Crab- <SEP> Pig- <SEP> Johnson- <SEP> Velvet <SEP> Yellow <SEP> Sickle Compound <SEP> grass <SEP> Cress <SEP> Brome <SEP> leaf <SEP> Foxtail <SEP> pod <SEP> grass <SEP> Weed <SEP> grass <SEP> leaf <SEP> Foxtail <SEP> pod <tb> 1 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 3 <SEP> 9 <SEP> 5 <SEP> 9 <tb> 2 <SEP> 7 <SEP> 8 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 2 <SEP> 3 <SEP> 5 <SEP> 1 <SEP> 2 <SEP> 0 <SEP> 3 <tb> 3 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 7 <SEP> 6 <SEP> 7 <SEP> 6 <SEP> 9 <SEP> 2 <SEP> 6 <SEP> 2 <SEP> 6 <tb> 4 <SEP> 8 <SEP> 9 <SEP> 2 <SEP> 9 <SEP> 6 <SEP> 8 <SEP> 5 <SEP> 9 <SEP> 2 <SEP> 4 <SEP> 2 <SEP> 4 <tb> 5 <SEP> 9 <SEP> 9 <SEP> 4 <SEP> 9 <SEP> 6 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 6 <SEP> 2 <SEP> 4 <tb> 6 <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 0 <SEP> 6 <SEP> 0 <SEP> 6 <tb> 7X <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 9 <SEP> 9 <SEP> 9 <tb> 7Y <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 5 <SEP> 6 <SEP> 2 <SEP> 9 <tb> 8 <SEP> 9 <SEP> 9 <SEP> 3 <SEP> 8 <SEP> 5 <SEP> 8 <SEP> 4 <SEP> 8 <SEP> 2 <SEP> 3 <SEP> 2 <SEP> 3 <tb> 9X <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 8 <SEP> 4 <SEP> 9 <tb> 9Y <SEP> 9 <SEP> 9 <SEP> 3 <SEP> 9 <SEP> 4 <SEP> 9 <SEP> 8 <SEP> 5 <SEP> 3 <SEP> 7 <SEP> 0 <SEP> 7 <tb> 10X <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 9 <SEP> - <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 1 <SEP> 4 <SEP> 3 <SEP> 6 <tb> 10Y <SEP> 8 <SEP> 9 <SEP> 3 <SEP> 8 <SEP> 3 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 2 <SEP> 4 <SEP> 0 <SEP> 5 <tb> 11X <SEP> 8 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 4 <SEP> 8 <SEP> 0 <SEP> 7 <SEP> 2 <SEP> 7 <tb> TABLE I - HERBICIDAL ACTIVITY (continued) EMI33.1 <SEP> Preemergence <SEP> Postemergence <tb> <SEP> Barnyard- <SEP> Garden <SEP> Downy <SEP> Velvet- <SEP> Yellow <SEP> Sickle- <SEP> Crab- <SEP> Pig- <SEP> Johnson- <SEP> Velvet <SEP> Yellow <SEP> Sickle Compound <SEP> grass <SEP> Cress <SEP> Brome <SEP> leaf <SEP> Foxtail <SEP> pod <SEP> grass <SEP> Weed <SEP> grass <SEP> leaf <SEP> Foxtail <SEP> pod <tb> 11Y <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 5 <SEP> 5 <SEP> 7 <SEP> 2 <SEP> 7 <SEP> 0 <SEP> 5 <SEP> 3 <SEP> 3 <tb> 12 <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 8 <SEP> 4 <SEP> 8 <tb> 13 <SEP> 9 <SEP> 9 <SEP> 3 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> - <SEP> 5 <SEP> 0 <SEP> 3 <SEP> 2 <SEP> 4 <tb> 14 <SEP> 8 <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 6 <SEP> 8 <SEP> 2 <SEP> 7 <SEP> 5 <SEP> 7 <tb> 15 <SEP> 8 <SEP> 7 <SEP> 2 <SEP> 6 <SEP> 5 <SEP> 6 <SEP> 2 <SEP> 6 <SEP> 0 <SEP> 4 <SEP> 0 <SEP> 5 <tb> 16 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 7 <tb> Example 18 - Herbicidal Selectivity In the following examples, the species of plants that were tested were: Barnyardgrass Downy brome Johnsongrass Wild oats - Avena fatua Yellow foxtail Goose grass - Eleusine indica L. Yellow nutsedge - Cyprus esculentus L. Cocklebur - Xanthum pennsylvanicum Morning glory - Ipomoea purpurea L. (Roth) Wild mustard - Brassica kaber Redroot pigweed SickIepod Velvetleaf Corn - Zea mays Cotton - Gossypium hirsutum Rioe - Oryza sativa Grain sorghum - Sorghum Soybeans - Beta vulgaris Wheat - Triticum aestivum Test Procedures The preemergence activity of compounds of Formula I was further determined with respect to certain species of crop plants and common species of weeds, by spraying a formulation of the test compounds on soil in small pots in which seeds of the plants had been scorn. The results of the tests were evaluated on the basis of the 0-9 scale described with respect to the earlier tests. The results of the tests are reported in Table II. TABLE II EMI35.1 <SEP> Rating <SEP> of <SEP> effect <SEP> at <SEP> indicated <SEP> dosage <SEP> (kg/na) <SEP> and <SEP> timing <tb> <SEP> Compound <SEP> 1 <SEP> Compound <SEP> 3 <SEP> Compound <SEP> 7X <SEP> Compound <SEP> 7Y <tb> <SEP> Pre-emergence <SEP> Preemergence <SEP> Postemergence <SEP> Preemergence <SEP> Preemergence <tb> Plant <SEP> Species <SEP> 0.25 <SEP> 0.0625 <SEP> 2.0 <SEP> 1.0 <SEP> 0.25 <SEP> 2.0 <SEP> 1.0 <SEP> 0.25 <SEP> 0.0625 <SEP> 0.25 <SEP> 0.0625 <tb> Corn <SEP> 3 <SEP> 0 <SEP> 4 <SEP> 2 <SEP> 0 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 0 <SEP> 2 <SEP> 0 <tb> Cotton <SEP> 0 <SEP> 2 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 0 <tb> Rice <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 5 <SEP> 2 <SEP> 2 <SEP> 9 <SEP> 7 <SEP> 8 <SEP> 0 <tb> Grain <SEP> Sorghum <SEP> 9 <SEP> 3 <SEP> 7 <SEP> 2 <SEP> 0 <SEP> 3 <SEP> 3 <SEP> 7 <SEP> 3 <SEP> 7 <SEP> 0 <tb> Soybean <SEP> 9 <SEP> 3 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 8 <SEP> 3 <tb> Sugar <SEP> Beet <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 6 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <tb> Wheat <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 5 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 8 <tb> Barnyard <SEP> Grass <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 1 <SEP> 0 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 7 <tb> Downy <SEP> Brome <SEP> 3 <SEP> 3 <SEP> - <SEP> - <SEP> - <SEP> 1 <SEP> 0 <SEP> 5 <SEP> 4 <SEP> 0 <SEP> 0 <tb> Johnsongrass <SEP> 7 <SEP> 2 <SEP> 9 <SEP> 7 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 8 <SEP> 0 <SEP> 9 <SEP> 6 <tb> Wild <SEP> Oats <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 9 <SEP> 5 <SEP> 9 <SEP> 9 <tb> Yellow <SEP> Foxtail <SEP> 7 <SEP> 5 <SEP> 8 <SEP> 8 <SEP> 4 <SEP> 7 <SEP> 6 <SEP> 7 <SEP> 0 <SEP> - <SEP> 6 <tb> YellowNutsedge <SEP> 3 <SEP> 3 <SEP> 4 <SEP> 0 <SEP> - <SEP> 2 <SEP> 0 <SEP> - <SEP> - <SEP> - <SEP> 0 <tb> TABLE II (continued) EMI36.1 <SEP> Rating <SEP> of <SEP> effect <SEP> at <SEP> indicated <SEP> dosage <SEP> (kg/na) <SEP> and <SEP> timing <tb> <SEP> Compound <SEP> 1 <SEP> Compound <SEP> 3 <SEP> Compound <SEP> 7X <SEP> Compound <SEP> 7Y <tb> <SEP> Pre-emergence <SEP> Preemergence <SEP> Postemergence <SEP> Preemergence <SEP> Preemergence <tb> Plant <SEP> Species <SEP> 0.25 <SEP> 0.0625 <SEP> 2.0 <SEP> 1.0 <SEP> 0.25 <SEP> 2.0 <SEP> 1.0 <SEP> 0.25 <SEP> 0.0625 <SEP> 0.25 <SEP> 0.0625 <tb> Goose <SEP> Grass <SEP> 9 <SEP> 3 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 9 <SEP> 0 <SEP> 9 <SEP> 9 <tb> COcklebur <SEP> 9 <SEP> 9 <SEP> - <SEP> 9 <SEP> - <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 9 <tb> Morning <SEP> Glory <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 4 <SEP> 7 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <tb> Mustard <SEP> 9 <SEP> 9 <SEP> - <SEP> - <SEP> - <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <tb> Pigweed <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <tb> Sicklepod <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 3 <SEP> 9 <SEP> 9 <tb> Velvetleaf <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 4 <SEP> 9 <SEP> 9 <tb> TABLE II (continued) EMI37.1 <SEP> Rating <SEP> of <SEP> effect <SEP> at <SEP> indicated <SEP> dosage <SEP> (kg/na) <SEP> and <SEP> timing <tb> <SEP> Compound <SEP> 9X <SEP> Compound <SEP> 9Y <SEP> Compound <SEP> 12 <tb> <SEP> Pre-emergence <SEP> Postemergence <SEP> Preemergence <SEP> Postemergence <SEP> Preemergence <tb> Plant <SEP> Species <SEP> 0.25 <SEP> 0.0625 <SEP> 1.0 <SEP> 0.25 <SEP> 0.25 <SEP> 0.0625 <SEP> 1.0 <SEP> 0.25 <SEP> 0.25 <SEP> 0.0625 <tb> Corn <SEP> 2 <SEP> 0 <SEP> 5 <SEP> 3 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 3 <SEP> 0 <SEP> 0 <tb> Cotton <SEP> 2 <SEP> 2 <SEP> 9 <SEP> 5 <SEP> 4 <SEP> 0 <SEP> 7 <SEP> 6 <SEP> 0 <SEP> 0 <tb> Rice <SEP> 9 <SEP> 6 <SEP> 2 <SEP> 0 <SEP> 6 <SEP> 4 <SEP> 3 <SEP> 2 <SEP> 9 <SEP> 5 <tb> Grain <SEP> Sorghum <SEP> 9 <SEP> 4 <SEP> 3 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 3 <SEP> 2 <SEP> 6 <SEP> 0 <tb> Sybean <SEP> 9 <SEP> 5 <SEP> 7 <SEP> 6 <SEP> 3 <SEP> 2 <SEP> 7 <SEP> 6 <SEP> 8 <SEP> 2 <tb> Sugar <SEP> Beet <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 9 <tb> Whsat <SEP> 9 <SEP> 7 <SEP> 4 <SEP> 0 <SEP> 9 <SEP> 4 <SEP> 2 <SEP> 1 <SEP> 9 <SEP> 7 <tb> Barnyard <SEP> Grass <SEP> 7 <SEP> 6 <SEP> 3 <SEP> 0 <SEP> 4 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 8 <SEP> 0 <tb> Downy <SEP> Brome <SEP> 6 <SEP> 0 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> - <SEP> - <SEP> 3 <SEP> 0 <tb> Johnsongrass <SEP> 7 <SEP> 5 <SEP> 3 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 4 <SEP> 2 <SEP> 7 <SEP> 0 <tb> TABLE II (continued) EMI38.1 <SEP> Rating <SEP> of <SEP> effect <SEP> at <SEP> indicated <SEP> dosage <SEP> (kg/na) <SEP> and <SEP> timing <tb> <SEP> Compound <SEP> 9X <SEP> Compound <SEP> 9Y <SEP> Compound <SEP> 12 <tb> <SEP> Pre-emergence <SEP> Postemergence <SEP> Preemergence <SEP> Postemergence <SEP> Preemergence <tb> Plant <SEP> Species <SEP> 0.25 <SEP> 0.0625 <SEP> 1.0 <SEP> 0.25 <SEP> 0.25 <SEP> 0.0625 <SEP> 1.0 <SEP> 0.25 <SEP> 0.25 <SEP> 0.0625 <tb> Wild <SEP> Oats <SEP> 9 <SEP> 8 <SEP> 6 <SEP> 0 <SEP> 4 <SEP> 0 <SEP> 5 <SEP> 2 <SEP> 9 <SEP> 0 <tb> Yellow <SEP> Foxtail <SEP> 6 <SEP> 3 <SEP> - <SEP> - <SEP> 0 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 9 <SEP> 0 <tb> Goose <SEP> Grass <SEP> 9 <SEP> 2 <SEP> 7 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 7 <SEP> 3 <SEP> 8 <SEP> 0 <tb> YellowNutsedge <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 3 <SEP> 1 <SEP> 0 <SEP> 0 <tb> Cocklebur <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 0 <SEP> - <SEP> - <SEP> 9 <SEP> 0 <tb> Morning <SEP> Glory <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 4 <SEP> 9 <SEP> 7 <tb> Mustard <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 7 <SEP> 6 <SEP> 3 <SEP> 9 <SEP> 5 <tb> Pigweed <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 7 <SEP> 7 <SEP> 6 <SEP> 9 <SEP> 5 <tb> Sicklepod <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 4 <SEP> 2 <SEP> 9 <SEP> 0 <tb> Velvetleaf <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 8 <SEP> 7 <SEP> 6 <SEP> 9 <SEP> 3 <tb> Nightshade <SEP> - <SEP> - <SEP> 9 <SEP> 8 <SEP> - <SEP> - <SEP> 9 <SEP> 8 <tb>

Claims: CLAIMS 1. A compound of the formula : EMI39.1 wherein Z is a bivalent group of the formila -CO-CO-, -CO-S-, -CO-CHOH-, or X is an oxygen atan or the group N-R2 wherein R2 is an alkyl group of from 1 to 3 carbon atans, or a cyclopropyl or methylcyclopropyl group ; one of R1 and R3 is an oxazolyl group of formula IIA EMI39.2 or, when Z is -CO-CO-, or -CO-CHOH-, may alternatively be the isateric formula IIB EMI39.3 and the other is an alkyl, haloalkyl or alkoxy group of 1 to 3 carbon atoms, a cycloalayl group of 3 to 6 carbon atoms or an alkenyl group of 3 to 5 carbon atoms; and R4 is a group containing 3 to 5 carbon atoms which is an alkyl, alkyl, alkynyl, alkoxyalkyl, alkylthioalkyl, alkylsulphinylalkyl, alkylsulphonylalkyl, cycloalkyl, alkylcycloalkyl or haloalkyl group; provided that what Z is -CO-CHOH then R2 is not haloalayl and R4 is not alkoxyalkyl, and when Z is -CH2-X-CH2-thenR4 is not haloalkyl. 2. A cavpound as claimed in claim 1 wherein one of R1 and represents an alkyl or alkoxy group. 3. A compound as cladded in claim 1 or 2 wherein R4 represents an alkyl, alkyl, alkoxyalkyl or alkylcycloalkyl group. 4. A compound as claimed in claim 2 and 3 wherein one of and R2 represents methyl or methoxy and R4 represents a butyl, ethynylprqpyl, methoxybutyl or methylcycloprspyl group. 5. A compound as claimed in claim 4 wherein R4 is tertiary butyl. 6. A compound as claimed in any one of the preceding claims wherein the oxazolyl substituant has the isaneric form given in formula IIA. 7. Process for the preparation of a compound of the general formula I as defined in claim 1 wherein Z represents -CO-CO-, -CO-S-, or -OO-CHOH-, which comprises warming a urea of formula III. R1 - - NH - CO NH - R2 III with, respectively, oxalyl chloride, (chlorothio)formyl- chloride, or glyoxylic acid in the presence of an inert solvent. 8. Process as claimed in claim 7 wherein, when a chloride is used, the reaction is carried out in the presence of a tertiary nitrogen base as hydrogen chloride acceptor. 9. Process for the preparation of a compound of the general formula I as defined in claim 1 wherein Z represents -CH20CH2- which comprises reacting a urea of formula III as defined in claim 7 with paraformaldehyde in an inert solvent and in the presence of an acid as catalyst. 10. Process for the preparation of a confound of the general formula I as defined in claim 1 wherein Z represents -CH2N(R3)-CH2- which comprises reacting a urea of formula III as defined in claim 7 with aqueous formaldehyde and reacting the resulting mixture with an amine of formula R3NH2. 11. A compound as defined in claim 1, whenever prepared by a process as claimed in any one of claims 7-10. 12. Herbicidal compositiotn, which comprises a compound as claimed in any one of claims 1-6 and 11, together with a carrier. 13. A composition as claimed in claim 12, which comprises at least two carriers, at least one of which is a surface-active agent. 14. Method of combating undesired plant growth at locus, which comprises treating the locus with a compound as claimed in any one of claims 1 to 6 and 11, or a composition as claimed in either of claims 12 or 13. 15. The use of a compound as claimed in any one of claims 1 to 6 and 11 as a herbicide.

Inventors: PILGRAM, KURT HANS GERHARD
Applicants: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.
Application year: 1984
Main classification: C07D413
IPC codes: A01N43, C07D413, C07D261, C07D417