(2-Imidazolin-2-yl)thieno and furo(2,3-b) and (3,2-b) pyridines and intermediates for the preparation thereof, and use of said compounds as herbicidal agents.

Abstract: There are provided novel (2-imidazolin-2-yl)- thieno and furo compounds, and intermediate compounds for the prep­ aration thereof, and a method for controlling a wide variety of annual and perennial plant species therewith.

Description: (2-IMIDAzOLIN-2-YL)THIENO- AND FURO[2,3-ti AND [3,2-b]PYRIDINES AND INTERMEDIATES FOR THE PREPARATION THEREOF, AND USE OF SAID COMPOUNDS AS HERBICIDAL AGENTS The present invention relates to novel (2imidazolin-2-yl)thieno- and furopyridine compounds, and intermediates for the preparation of said pyridine compounds and a method for controlling undesirable annual and perennial plant species therewith. More particularly, this invention relates to 6-(2-imidazolin-2-yl)thieno- and furo[2,3-b] and 5-(2imidazolin-2-yl)thieno- and furo[3,2-bjpyridine compounds and the corresponding 2,3-dihydrothieno and 2,3-dihydrofuro compounds having the structures (Ia) and (Ib): EMI1.1 wherein - - represents a single or a double bond; RI is C1-C4 alkyl; R2 is C1-C4 alkyl or C3-C6 cycloalkyl; and when R1 and R2 are taken together with the carbon to which they are attached they may represent C3-C6 cycloalkyl optionally substituted with methyl; A is COOR3, CHO, CH2OH, COCH2OH, CONHCH2CH2OH, CONHOH, or EMI2.1 R3 is hydrogen, C1-C12 alkyl, which may be interrupted by one or more 0 or S and is optionally substituted with one of the following groups: C1-C3 alkoxy, halogen, hydroxy, C3-C6 cycloalkyl, benzyloxy, furyl, phenyl, furfuryl, halophenyl, loweralkylphenyl, loweralkoxyphenyl, nitrophenyl, carboxyl, loweralkoxycarbonyl, cyano, Cl-C4 alkylthio or triloweralkylammonium, C3-C6 alkenyl optionally substituted with one of the following groups: Cl-C3 alkoxy, phenyl, halogen or with two C1-C3 alkoxy groups or two halogen groups: C3-C6 cycloalkyl optionally substituted with one or two C1-C3 alkyl groups; C3-Clo alkynyl optionally substituted with phenyl, halogen or CH2OH; or a cation of alkali metals, alkaline earth metals, (Ca, Ba) manganese, copper, iron, ammonium or organic ammonium; Rc and RD are H or CH3; B is H, COR4 or S02Rg, provided that when B is COR4 or S02Rg, and A is COOR3 R3 cannot be hydrogen or a salt-forming cation; R4 is Cl-Cll alkyl, chloromethyl or phenyl optionally substituted with one chloro, one nitro, one methyl, or one methoxy group; R5 is C1-Cg alkyl or phenyl optionally substituted with one methyl group, chloro or nitro; W is O or S; X is 0, S, or, where - - is a single bond, -=0; Y and Y', Z and Z' are hydrogen, halogen, C1-C6 alkyl, C1-C4 hydroxyloweralkyl, Cl-C6 alkoxy, Cl-C6 acyloxy, benzoyloxy optionally substituted with one or two C1-C4 alkyl, C1-C4 alkoxy, halogen; C1- C4 alkylthio, phenoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, nitro, cyano, C1-C4 alkylamino, Cl-C4 dialkylamino, Cl- C4 alkylsulfonyl or phenyl optionally substituted with one or two C1-C4 alkyl, C1-C4 alkoxy, halogen, or any combination of two of these groups and wherein Y and Z are the same group provided that Y and Z are H, halogen, alkyl or alkoxy, and when Y and Y' or Z and Z' are the same group they are hydrogen or alkyl; and, when taken together, Y and Z may form a ring in which YZ are represented by the structure -(CH2)n-, where n is an integer selected from 3 or 4; or EMI3.1 where L, M, Q and R7 each represent hydrogen, halogen, nitro, C1-C4 loweralkyl, C1-C4 loweralkoxy, methoxy, phenyl and phenoxy, with the proviso that only one of L, M, Q or R7, may represent a substituent other than hydrogen, halogen, C1-C4 alkyl or C1-C4 alkoxy; or the pyridine N-oxides thereof, when W is O or S and A is COOR3; and when R1 and R2 are not the same, the optical isomers thereof, and, except when R3 is a salt-forming cation, the acid addition salts thereof. A preferred group of 6-(2-imidazolin-2-yl)thieno- and furo[2,3-bjpyridine and 5-(2-imidazolin2-yl)thieno- and furo[3,2-bjpyridine compounds have the formula shown as (Ia) and (Ib) above, wherein Rl is methyl; R2 is methyl, ethyl, propyl, isopropyl, or when taken together form a cyclohexyl or methylcyclohexyl ring; W is oxygen or sulfur; B is hydrogen; A is COOR3, where R3 is as described above; Y and Z are hydrogen, Cl-C3 alkyl, Cl-C3 alkoxy, alkylthio, halo, nitro, cyano, trifluoromethyl, monofluoromethyl, difluoromethyl, monofluoromethoxy, difluoromethoxy, trifluoromethoxy, methylsulfonyl, methylsulfonamido, methylamino, dimethylamino, or isopropylamino and when Y and Z are taken together, YZ is -(CH2)3, -(CH2)4-, or -CH=CH-CH=CH-. The most preferred formula (Ia) and (Ib) (2-imidazolin-2-yl)thieno and furo compounds are those wherein B is H, Y and Z are hydrogen, chloro, methyl or methoxy provided that one of either Y or Z is hydrogen; W is oxygen; A is COOR3 where R3 is hydrogen, furfuryl, propynyl, C3-haloalkenyl, Nad or isopropylammonium and R1 and R2 are as defined for the preferred compounds. It should also be understood that when B is H the imidazolinyl thieno- and furo[2,3-b] and 13,2-bl- pyridines represented by formula (Ia) and (Ib) above may be tautomeric. While, for convenience, they are depicted by single structures identified as formula (Ia) and (Ib), they may exist in either of the tautomeric forms illustrated as follows: EMI5.1 As such, both tautomeric forms of said imidazolinylpyridines are meant to be included under the formula (Ia) and (Ib) definition. The present invention also relates to novel substituted thieno- and furoimidazopyrrolopyridinedione compounds of structure (via) and (IIb) below and a method for controlling undesirable annual and perennial plant species therewith in soybeans and certain cereal crops: EMI5.2 wherein X, Y, Y', Z, Z', W, R1 and R2 are as described for (Ia) and (Ib) above and wherein X, Y, Z, W, R1 and R2 in the preferred and most preferred formula (IIa) and (IIb) compounds are as described for the preferred and most preferred formula (Ia) and formula (Ib) compounds. Herbicidal substituted pyridine and quinoline2-imidazolin-2-yl acids, esters and salts are disclosed in European Patent Application Number 81103638.3 filed December 1, 1981. The present invention relates to novel thieno- and furol2,3-b]pyridines and thieno- and furo13,2-b]pyridines which when substituted in the 6 or 5 position with an imidazolinone ring and in the 5 or 6 position with a group A as previously defined, provide potent herbicidal agents. The finding that imidazolinyl thieno- and -furopyridines provide potent herbicides is unexpected as there is no prior indication that such 12,3-b] or [3,2-b] ring systems may be employed for any agronomic or herbicidal utility. This new class of herbicidal agents is highly effective when applied as a pre- or postemergence treatment, and individual members of this class exhibit unusual selectivity in soybean and cereal crops such as wheat, barley, rice, rye and oats. Further, it has been found that selectivity in cereals may be enhanced when A is CO2H, by the preparation of esters, particularly furfuryl, alkynyl and haloalkenyl esters. Additionally some members of this class exhibit unexpected plant growth regulating effects such as reduced plant height and anti lodging activity and increased tillering in cereal crops. The compounds of the present invention may conveniently be prepared from the appropriately substituted thieno- and furo[2,3-b] and [3,2-b]pyridine- dicarboxylic acids and esters of formula (IIIa) and (IIIb): EMI7.1 wherein X, Y and Z are as previously described and R is methyl or ethyl. Methods suitable for preparing novel formula (Ia) and formula (Ib) unsaturated compounds wherein - is a double bond from the novel formula (IIla) and (IIIb) pyridinedicarboxylic acid esters are illustrated in Flow Diagram I below. Thus formula (IIIa) and (IIIb) diesters may be hydrolyzed to the corresponding thieno- and furo2,3-pyridinedicarboxylic acids of formula (IVa) and (IVb) by reaction thereof with a strong base such as potassium hydroxide or sodium hydroxide. Acid anhydrides of formula (Va) and (Vb) may then be prepared by treatment of the formula (IVa) and (IVb) pyridinedicarboxylic acids with, for example, acetic anhydride. Reaction of formula (Va) and (Vb) anhydrides with an appropriately substituted aminocarboxamide or aminothiocarboxamide depicted by formula (VI) yields carbamoyl nicotinic acids of formula (VIIa) and (VIIb). Treatment of the thus-formed formula (VIla) and (VIIb) carbamoyl nicotinic acids with about 2 to 10 molar equivalents of aqueous or aqueous alcoholic sodium or potassium hydroxide, preferably under a blanket of inert gas such as nitrogen, cooling and acidifying to pH 2 to 4 with a strong mineral acid such as hydrochloric acid or sulfuric acid gives herbicidally effective 6-(4,4-disubstituted-5-oxo-(or thioxo)-2imidazolin-2-yl)thieno- and furo[2,3-bjpyridine-5- carboxylic acids, and 5-(4,4-disubstituted-5-oxo-(or thioxo)-2-imidazolin-2-yl)thieno- and furot3,2-bJ- pyridine-6-carboxylic acids encompassed by formulas (Ia) and (Ib). Formula (Ia) and (Ib) 5 or 6-(2-imidazolin-2yl)thieno- and furopyridine esters, wherein A is COOR3 and R3 represents a substituent other than hydrogen or a salt-forming cation, and Rl, R2, X, Y and Z are as described above can be prepared by reacting a novel thieno- or furoimidazopyrrolopyridinedione, represented by formulas (IIa) and (IIb), hereinbelow, in Flow Diagram (II), with an appropriate alcohol and corresponding alkali metal alkoxide at a temperature ranging between about 200C and about 500C. Formula (I Ia) and (IIb) novel thieno- and furoimidazopyrrolopyridinediones may conveniently be prepared fro formula vIa) and (Ib) acids, where B is H by treatment with one equivalent of dicyclohexylcarbodiimide in an inert solvent such as methylene chloride as illustrated in Flow Diagram (II) below. FLOW DIAGRAM (I) EMI9.1 FLOW DIAGRAM (I) (Continued) EMI10.1 FLOW DIAGRAM (II) EMI11.1 where MI is an alkali metal, and X, Y, Z, Ri, R2 and R3 are as above defined. Many formula (lIla) thieno[2,3-b]pyridinedi- carboxylic acids and (IlIb) thieno[3,2-b]pyridinedi- carboxylic acids may conveniently be prepared by reacting the appropriately substituted 2 or 3-aminothiophene of formula (VIlla) or (VIIIb), where R is hydrogen or chloro, with a Cl-C4 alkyl ester of acetylenedicarboxylic acid of formula (IX) as described by Bleckert et al. Chem. Ber. 1978, 106, 368. The thus-formed ss-aminothieno-&alpha;,ss-unsaturated ester of formula (X) is then reacted with an immonium salt depicted by the formula Cl-CH=CH=N-(R'''#2 Cl# wherein R''' is C1-C6 alkyl or Cl-CH=N (CH2)n' C? where n' is 4 or 5, in the presence of a low boiling chlorinated hydrocarbon solvent such as methylene chloride or dichloroethane at a temperature between about 400C and 900C, for a period of time sufficient to essentially complete the reaction and yield the formula (tufa) 12,3-b3- thieno- or (IIIb) [3,2-blthieno-2,3-pyridinedicarbo- xylic acid as the dialkyl ester as illustrated in Flow Diagram (III) below, Formula (limb) furo[3,2-b]pyridinedicarboxylic acids may be prepared by reacting 3-amino-2formylfuran of formula (XI) prepared by the method of S. Gronowitz et al., Acta Chemica Scand B29 224(1975) with ethyl oxalacetate to give formula (lib) furopyridine compounds directly, as illustrated in Flow Diagram (IV) below while formula (IIIa) furo[2,3-b]- pyridine compounds where Y and Z are H are obtained by bromination of the reaction product (XII) of acetoacetamide with the diethyl ester of ethoxymethyleneoxalacetic acid followed by treatment with sodium borohydride and para-toluene sulfonic acid in refluxing xylene as illustrated in Flow Diagram (V) below. Formula (IIIb) 2,3-dihydrofuro[3,2-b] and thieno[3,2-b]pyridines may be prepared by the reaction of diethylethoxymethylene oxalacetate with a mixture of enamines derived from 3-keto-tetrahydrofuran or 3-ketotetrahydrothiophene, followed by treatment with ammonia or ammonium, as illustrated in Flow Diagram (VI). This procedure is described in pending application for United States Letters Patent, Serial No of J. Johnson, filed. FLOW DIAGRAM (III) EMI14.1 FLOW DIAGRAM (IV) EMI15.1 FLOW DIAGRAM (V) EMI16.1 FLOW DIAGRAM (VI) EMI17.1 wherein Rl and R2 each represents Cl-C6 alkyl or taken together with the nitrogen atom to which they are attached form a 5 or 6 membered saturated heterocyclic ring, optionally containing at most 2 hetero atoms. Formula (IIla) furo[2,3-b}pyridine compounds where Z is H and Y is alkyl or optionally substituted phenyl are prepared by reaction of an acetylene compound with the iodopyridine diester (VII) [preparation of this compound VII is described in J. Prakt. Chem., 148; 72(1937)1, in the presence of cuprous salts, an amine base, and a palladium (II) catalyst as shown in Flow Diagram (VII). FLOW DIAGRAM (VII) EMI19.1 Substituents represented by Y and Z in formula (Ia), (Ib), (IIa) and (IIb) compounds of the present invention may be prepared either by using the appropriately substituted starting material for the preparation of formula (lila) and (IIIb) thieno- and furopyridine-5,6-dicarboxylic acid esters or by electrophilic substitution (halogenation, nitration, sulfonation, etc.) directly upon Formula (IIIa) or (IIIb) diesters or Formula (Ia) or (Ib) final products, wherein at least one of Y or Z is hydrogen. These substituted Formula (lIla), (IlIb), (Ia) and (Ib) compounds then may be used as starting materials for additional Y and Z substitution by displacement, reduction, oxidation, etc. Representative substituted (IIIa) and (IIIb) compounds which may be prepared by these procedures are as illustrated below. EMI20.1 (IIIa) (IIIb) X Y Z R S H H CH3 S H Br CH3 S CH3 H CH3 S H Cl CH3 S Cl Cl CH3 S H I CH3 S H N02 CH3 S Br Br CH3 EMI21.1 <tb> X <SEP> Y <SEP> z <SEP> R <tb> S <SEP> CH3 <SEP> Cl <SEP> CH3 <tb> S <SEP> H <SEP> CH3 <SEP> CH3 <tb> S <SEP> Cl <SEP> H <SEP> CH3 <tb> S <SEP> CH3 <SEP> CH3 <SEP> CH3 <tb> S <SEP> H <SEP> CN <SEP> CH3 <tb> S <SEP> H <SEP> OCH3 <SEP> CH3 <tb> S <SEP> H <SEP> N(CH3)2 <SEP> CH3 <tb> S <SEP> H <SEP> SCH3 <SEP> CH3 <tb> S <SEP> H <SEP> OCF2H <SEP> CH3 <tb> O <SEP> H <SEP> H <SEP> C2H5 <tb> O <SEP> H <SEP> Br <SEP> CH3 <tb> O <SEP> H <SEP> Br <SEP> C2H5 <tb> O <SEP> H <SEP> Cl <SEP> CH3 <tb> O <SEP> H <SEP> Cl <SEP> C2H5 <tb> O <SEP> CH3 <SEP> H <SEP> CH3 <tb> O <SEP> CH3 <SEP> H <SEP> C2H5 <tb> O <SEP> H <SEP> CH3 <SEP> CH3 <tb> O <SEP> C2H5 <SEP> H <SEP> CH3 <tb> O <SEP> H <SEP> C2HS <SEP> CH3 <tb> O <SEP> CH3 <SEP> CH3 <SEP> CH3 <tb> S <SEP> -(CH2)3- <SEP> CH3 <tb> S <SEP> -(OH2)4- <SEP> CH3 <tb> S <SEP> -(GH)4- <SEP> OH3 <tb> S <SEP> C6H5 <SEP> H <SEP> CH3 <tb> O <SEP> CgH5 <SEP> H <SEP> CH3 <tb> S <SEP> H <SEP> 50 <SEP> 4 <SEP> H3 <SEP> CH3 <tb> <SEP> CH3 <tb> X y Z R S H OC6H5 CH3 O H OC6H5 CH3 O CF3 H CH3 O H N02 C2H5 O Br Br C2H5 o H C6H5S C2H5 O H CF3 C2H5 Additionally, novel herbicidal 2,3-dihydro thieno[2,3-b] and [3,2-bipyridine compounds may be obtained by starting the sequence in Flow Diagram (III) above with a dihydrothiophenimin hydrochloride. Novel herbicidal 2,3-dihydro furo[2,3-b] and [3,2-b]pyridines may be prepared by catalytic reduction of the formula (Ia) or (Ib) (2-imidazolin-2-yl) product, or (IIIa) and (IIIb) furo[2,3-b] and [3,2-b]pyridine-5,6-diesters as for example with hydrogen and palladium on carbon, provided that Y and Z are substituents which are not reduced by such a procedure. Other 2,3-dihydrofuro 12,3-b}pyridines are prepared by the reduction-rearrangement of a bromo ketone with sodium borohydride followed by treatment with triethylamine, and p-toluene- sulfonic acid as shown in Flow Diagram (VIII). This then provides novel 2,3-dihydro herbicidal compounds illustrated below. EMI23.1 wherein X, Y, Y', Z, Z', W, B, R1 and R3 are as described for (Ia) and (Ib). FLOW DIAGRAM (VIII) EMI24.1 FLOW DIAGRAM (VIII) (Continued) EMI25.1 The formula (Ia) and formula (Ib) 6-(2imidazolin-2-yl)thieno- and furo[2,3-blpyridines and 5-(2-imidazolin-2-yl)thieno- and furo[3,2-bjpyridines and the formula (I Ia) and formula (IIb) imidazopyrrolopyridinediones of the present invention are exceedingly effective herbicidal agents useful for the control of an exceptionally wide variety of herbaceous and woody annual and perennial monocotyledonous and dicotyledonous plants. Moreover, these compounds are herbicidally effective for controlling weeds indigenous to both dry land and wet land areas. They are also useful as aquatic herbicides and are unique in their effectiveness in controlling the above-said plants when applied to the foliage thereof or to soil or water containing seeds or other propagating organs of said plants such as tubers, rhizomes or stolons, at rates of from about 0.016 to 4.0 kg/ha, and preferably at rates from about 0.032 to 2.0 kglha. It is, of course, obvious that rates of application above the 4.0 kg/ha level can also be used to effectively kill undesirable plant species; however, rates of application of toxicant above the level necessary to kill the undesirable plants should be avoided since application of excessive amounts of toxicant is costly and serves no useful function in the environment. Among the plants which may be controlled with the compounds of this invention are: Elatine triandra, Sagittaria pygmaea, Scirpus hotarui, Cyperus serotinus, Eclipta alba, Cyperus difformis, Rotala indica, Lindernia pyridoria, Echinochloa crus-galli, Digitaria sanguinalis, Setaria viridis, Cyperus rotundus, Convolvulus arvensis, Agropyron repens, Datura stramonium, Alopercurus myosuroides, Ipomoea spy., Sida spinosa, Ambrosia artemisiifolia, Eichhornia crassipes, Xanthium pensylvanicum, Sesbania exaltata, Avena fatua, Abutilon theophrasti, Bromus tectorum, Sorghum halepense, Lolium spy., Panicum dichotomiflorum, Matricaria spp., Amaranthus retroflexus, Cirsium arvense and Rumex iaponicus. It has been found that the formula (la) and (Ib) (2-imidazolin-2-yl)thieno- and furopyridines are generally selective herbicides, particularly effective for controlling undesirable weeds in the presence of leguminous crops such as soybeans, and cereal crops such as wheat, barley, oats and rye. However, certain of the formula (Ia) and formula (Ib) compounds are less selective than others in this series. It has also been found that several of the formula (Ia) and formula (Ib) (2-imidazolin-2-yl)- pyridines are effective as antilodging agents in cereal crops when applied at rates of application between about 0.016 to 4.0 kg hectare. At rates of application not exceeding about 0.010 kg per hectare, it has also been found that certain of the formula (Ia) and formula (Ib) thieno- and furopyridines are effective for increasing branching of leguminous crops and tillering of cereal crops. Since the formula (Ia) and formula (Ib) imidazolinylthieno- and furopyridines and derivatives, wherein R3 is a salt-forming cation, are water soluble, these compounds can simply be dispersed in water and applied as a dilute aqueous spray to the foliage of plants or to soil containing propagating organs thereof. These salts also lend themselves to formulation as flowable concentrates. The formula (Ia) and formula (Ib) (2-imidazolin-2-yl)thieno- and furopyridines and the formula (Ila) and formula (IIb) imidazopyrrolopyridinediones can also be formulated as wettable powders, flow concentrates, emulsifiable concentrates, granular formulations and the like. Wettable powders can be prepared by grinding together about 20% to 45% by weight of a finely divided carrier such as kaolin, bentonite, diatomaceous earth, attapulgite, or the like, 45% to 80 by weight of the active compound, 2% to 5% by weight of a dispersing agent such as sodium lignosulfonate, and 2% to 5% by weight of a nonionic surfactant, such as octylphenoxy polyethoxy ethanol, nonylphenoxy polyethoxy ethanol or the like. A typical flowable liquid can be prepared by admixing about 40Z by weight of the active ingredient with about 2% by weight of a gelling agent such as bentonite, 3% by weight of a dispersing agent such as sodium lignosulfonate, 1% by weight of polyethylene glycol and 545 by weight of water. A typical emulsifiable concentrate can be prepared by dissolving about 5% to 25% by weight of the active ingredient in about 65% to 90% by weight of N-methylpyrrolidone, isophorone, butyl cellosolve, methylacetate or the like and dispersing therein about 5% to 10% by weight of a nonionic surfactant such as an alkylphenoxy polyethoxy alcohol. This concentrate is dispersed in water for application as a liquid spray. When the compounds of the invention are to be used as herbicides where soil treatments are involved, the compounds may be prepared and applied as granular products. Preparation of the granular product can be achieved by dissolving the active compound in a solvent such as methylene chloride, N-methylpyrrolidone or the like and spraying the thus prepared solution on a granular carrier such as corncob grits, sand, attapulgite, kaolin or the like. The granular product thus prepared generally comprises about 3 to 20% by weight of the active ingredient and about 97% to 80% by weight of the granular carrier. In order to facilitate a further understanding of the invention, the following examples are presented primarily for the purpose of illustrating certain more specific details thereof. The invention is not to be deemed limited thereby except as defined in the claims. Unless otherwise noted, all parts are by weight. EXAMPLE 1 Preparation of dimethyl thieno[3,2-jpyridine-5,6- d icarboxylate EMI30.1 A mixture of isopropyl-3-thiophenecarbamate (177 g; 0.975 mol) in methanol (1.2 1) and water (2.8 1) containing sodium hydroxide (200 g) is heated at reflux for four hours. Methanol is removed under reduced pressure and the cooled reaction extracted with ether (5 1), and these extracts are washed with water, aqueous sodium chloride and dried. Evaporation under reduced pressure affords 3-aminothiophene as an oil in 57% crude yield. 3-Aminothiophene is redissolved in methanol (500 mL) cooled in an ice bath and dimethylacetylenedicarboxylate (80 g; 0.50 mol) is added dropwise. The mixture is stirred at room temperature for 15 hours and 30 minutes, the methanol removed under reduced pressure and l,2-dichloroethane is added. This solvent is also evaporated off to give dimethyl 3-thienylaminobutenedioate as an oil. A Vilsmeier reagent is prepared by adding dropwise, with stirring phosphorus oxychloride (86 g, 0.56 mol) to a cooled (50C) solution of DMF (41 g, 0.56 mol) in 1,2-dichloroethane (200 mL). This reagent is stirred at room temperature for one hour and 40 minutes, diluted with 1,2-dichloroethane (100 mL), cooled to 50C and then the above dimethyl ester dissolved in 1,2-dichloroethane (400 mL) is added to the Vilsmeier reagent at 50C dropwise over a 25 minute period. The reaction temperature is raised to room temperature for 15 minutes, then to reflux for a further two hours and 25 minutes. The cooled reaction mixture is chromatographed directly on a silica gel column affording 35.7 g (15%) of dimethyl thieno[3,2-b ]pyridine-5,6-dicarboxylate mp 124-125.50C after crystallization from hexane-ethylacetate. A second crop 10.3 g with mp 121-1240C is obtained giving an overall yield from isopropyl 3-thiophenecarbamate of 19%. Utilizing the above procedure and substituting the appropriate substituted aminothiophene for isopropyl 3-aminothiophenecarbamate yields the compounds illustrated below. EMI31.1 Y Z R mpOC H H CH3 126-127 CH3 H CH3 C1 H CH3 149-151 EXAMPLE 2 Preparation of dimethyl thieno[3,2-b]pyridine-5,6- dicarboxylate EMI32.1 To concentrated sulfuric acid (170 mL), stirred at room temperature is added in portions 3acetylamino-2-formylthiophene (17.5 g, 0.103 mol). The mixture is heated at 500C for 30 minutes, cooled and poured into an ice-water mixture. After neutralizing with an excess of sodium acetate, the mixture is ether (1 x 2 mL) extracted. The organic layer was dried over anhydrous Na 2S04 and stripped to a dark red gum consisting of 3-amino-2-formylthiophene. Dimethylacetylenedicarboxylate (DMAD) (13 mL) in acetic acid (5 mL), piperidine (5 mL), methylene chloride (100 mL) and toluene (100 mL) is added to the 3-amino-2-formylthiophene and the mixture stirred overnight. Methylene chloride is removed by distillation and then the mixture heated at reflux for 24 hours. After cooling an additional 13 mL of DMAD is added and the reaction heated to reflux again for seven and one-half hours. After standing for 60 hours at room temperature, the solvents are removed and the dimethyl thieno[3,2-b]pyridine-5,6dicarboxylate product is obtained by chromatography, after eluting with hexane-ethyl acetate, mp 124-1250C. EXAMPLE 3 Preparation of dimethyl 3-chlorol3,2-blpyridine-5,6- dicarboxylate and dimethyl 2,3-dichlorotbienol3, 2-kl- pyridine-5 , 6-dicarboxylate EMI33.1 A solution of dimethyl thieno[3,2-b]pyridine5,6-dicarboxylate (15 g 0.0525 mol) in acetic acid (680 mL) and sodium acetate (86 g, 0.093 mol) is maintained at 580C while chlorine is slowly introduced during five hours and 45 minutes. After reaction is complete, the mixture is flushed with nitrogen, ethyl acetate (200 mL) is added and solid sodium chloride filtered off and washed with ethyl acetate. The mother liquors and washes are combined and the solvents removed under reduced pressure. The residue is dissolved in methylene chloride and the solution washed with water, back extracted with methylene chloride and the combined methylene chloride layers washed with aqueous sodium bicarbonate, dried and stripped to give 18 g of solid. Chromatography on silica gel with 15% ethyl acetatehexane, then 20% ethyl acetate-hexane gives the 2,3dichloro compound, mp 173-1780C, 1.3 g, followed by the 3-chlorothieno compound mp 166-1730C after crystallization from ethyl acetate-hexane. EXAMPLE 4 Preparation of dimethyl 3-bromothienot3,2-blpyridine- 5, 6-dicarboxylate EMI34.1 A solution of bromine (20 g, 0.125 mol) in acetic acid (50 mL) is added dropwise over three hours to a solution of dimethyl thieno[3,2-b3pyridine-5,6-di- carboxylate, (26.3 g, 0.104 mol), containing sodium acetate (17.2 g, 0.2 mol) in acetic acid (300 mL) at 850C. Additional sodium acetate (18 g)-and bromine (20 g) in acetic acid (50 mL) is added over an hour and the mixture stirred at 850C overnight. Bromine (10 g) is added in one portion then left at 850C for four hours. The mixture is cooled and treated with aqueous sodium bisulfite, diluted with ethyl acetate and concentrated. The reaction product is partitioned between water and methylene chloride and the organic layer washed with aqueous sodium chloride and the solvent removed. The residue is washed with ether to give 25 g of crude product, mp 165-1680C. Recrystallization from methanol gave needles of dimethyl 3-bromothienoj3,2-b]- pyridine-5,6-dicarboxylate, mp 168-1690C. EXAMPLE 5 Preparation of thieno[3,2-k]pyridine-5,6-dicarboxylic acid EMI35.1 Dimethyl thieno[3,2-b]pyridine-5,6-dicarboxy late (3.75 g, 0.0149 mol) is added to a solution of sodium hydroxide (1.8 g, 0.045 mol) in water (20 mL) and the mixture is warmed at 600C for 20 hours. The reaction mixture is diluted with water, cooled in an ice bath, and acidified by the addition of concentrated hydrochloric acid. A precipitate of thienol3,2-b]- pyridine-5,6-dicarboxylic acid is filtered off and dried overnight to give 3.1 g (93%) mp > 3800C. Utilizing the above procedure and substituting the appropriate substituted thienot3,2-b]- pyridine-5,6-dicarboxylic acid diester yields the compounds illustrated below. EMI35.2 Y Z mp C H H > 380 H Cl None taken H Br > 380 H I H F H CN H OCH3 H N02 H N(CH3)2 CH3 H H CH3 CH3 CH3 H OCHF2 H SCH3 H S02N(CH3)2 C6H5 H -(CH2)3 -(CH2)4 -(CH)4 Cl Cl H C6H5 C6H5 H H OC6H5 CF3 H C2H5 H H C2H5 H SC6H5 H CF3 H CHO H CH2Cl EXAMPLE 6 Preparation of 3-chlorothieno[3,2-b]pyridine 5,6dicarboxylic acid anhydride EMI37.1 3-Chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid (1.45 g) is heated at 85 to 900C for 30 minutes then 90 to 1020C for 30 minutes in acetic anhydride (7 mL). The reaction is cooled, the solids filtered off and washed with ether to give 1.2 g of 3-chloro tbienol3,2-b]pyridine-5,6-dicarboxylic acid anhydride. The proton magnetic resonance spectrum is consistant with the structure. Utilizing the above procedure and substituting the appropriate pyridine-5,6-dicarboxylic acid for 3-chlorothienoj3,2-b]pyridine-5,6-dicarboxylic acid yields the compounds illustrated below. EMI37.2 Y z mp C H H 266-267 H Cl Solid no mp obtained H Br > 380 Cl H Cl Cl H N02 CH3 H H N(CH3)2 H SCH3 H OCH3 H CH3 H F H I CH3 CH3 H CN H OCHF2 H S02N(CH3)2 -(CH2)3- -(CH2)4 -(CH)4 H C6H5 C6H5 H H OC6H5 CF3 H C2H5 H H C2H5 H SC6H5 H CF3 H CHO H CH2Cl EXAMPLE 7 Preparation of 5-[(l-carbamoyl-1,2-dimethylpropyl)-3- chlorothieno[3,2-lpyridine-6-carboxylic acid EMI39.1 2-Amino-2,3-dimethylbutyramide (0.71 g) all in one portion is added to a stirred solution of 3-chloro thienol3,2-b]pyridine-5,6-dicarboxylic acid anhydride, (1.2 g) in THF (1.0 mL). After standing for five minutes, the ice bath is removed and the reaction stirred at room temperature for 28 hours. THF (5 mL) is added and the mixture heated at reflux for two hours and then set aside overnight. The cooled mixture is filtered and the collected solid washed with ether to give 1.4 g of the desired 5-[(1-carbamoyl-1,2-dimethylpropyl)carbamoyl]- 3-chlorothienot3,2-b]pyridine-6-carboxylic acid. Utilizing the above procedure and substituting the appropriate pyridine-5,6-dicarboxylic acid anhydride for 3-chlorothieno[3,2-b]pyridine-5,6-dicarboxylic acid anhydride and the appropriate aminoamide yields the compounds illustrated below. EMI40.1 Y Z R1 R2 mp C H H CH3 i-C3H7 H cl CH3 i-C3H7 not pure Cl H CH3 i-C3H7 Cl Cl CH3 i-C3H7 H Br CH3 i-C3H7 H CH3 CH3 i-C3H7 H N02 CH3 i-C3H7 H N(CH3)2 CH3 i-C3H7 H SCH3 CH3 i-C3H7 H OCH3 CH3 i-C3H7 CH3 H CH3 i-C3H7 H H CH3 C3H7 H H CH3 C2H5 H OCHF2 CH3 i-C3H7 CH3 CH3 CH3 i-C3H7 H CN CH3 i-C3H7 H F CH3 i-C3H7 H I CH3 i-C3H7 H S02N(CH3)2 CH3 i-C3H7 C6H5 H CH3 i-C3H7 -(CH2)3- CH3 i-C3H7 -(CH2)4- CH3 i-C3H7 -(CH)4- CH3 i-C3H7 H C6H5 CH3 i-C3H7 Y Z R1 R2 mp C C2H5 H CH3 i-C3H7 H OC6H5 CH3 i-C3H7 H CH2Cl CH3 i-C3H7 CF3 H CH3 i-C3H7 H C2H5 CH3 i-C3H7 H CHO CH3 1-C3H7 H CF3 CH3 i-C3H7 H SC6H5 CH3 i-C3H7 EXAMPLE 8 Preparation of 5-(5-isopropyl-5-methyl-4-oxo-2-imidazo lin-2-ylithieno[3,2-b]pyridine-6-carboxylic acid EMI42.1 Thieno[3,2-b]pyridine-5,6-dicarboxylic acid (2.5 g, 0.011 mol) is heated slowly to 850C for one hour with acetic anhydride (25 mL), then cooled, filtered and washed with diethyl ether to give the anhydride as a solid, mp 266-2670C. A mixture of the anhydride and 2-amino-2,3-dimethylbutyramide (2.6 g, 0.02 mol) in THF (70 mL) is stirred at room temperature for 15 hours. After heating at reflux for two hours, the mixture is cooled and diluted with THF (50 mL). Solid 5-[(l-car- bamoyl-l,2-dimethylpropyl)carbamoyl]thieno[3,2-b]- pyridine-6-carboxylic acid is filtered off, washed with ether and dried. The above solid is mixed with an aqueous 60 mL) solution of sodium hydroxide (6 g 0.05 mol) and heated at 850C for two hours and 30 minutes, then set aside at room temperature overnight. After cooling in an ice bath, the mixture is acidified to pH 3 with concentrated hydrochloric acid. A solid (3 g) is filtered off and dried. Crystallization from ethyl acetate affords (5- (5-isopropyl-5-methyl-4-oxo-2-imidazo- lin-2-yl)thieno[3,2-b]pyridine-6-carboxylic acid, mp 242-2440C in 46% yield. Utilizing the above procedure and substituting the appropriate pyridine-5,6-dicarboxylic acid for thieno[3,2-b]pyridine-5,6-dicarboxylic acid yields the compounds illustrated below. EMI43.1 Y z mpOC H H 242-244 H C1 238-239 H Br 226-227 C1 H 247-248 Y Z mp C Cl Cl H CH3 CH3 H H NO2 H N(CH3)2 H SC6H5 H SCH3 H OCH3 H OCHF2 CH3 CH3 H CH H SO2N(CH3)2 C6H5 H -(CH2)3 -(CH2)4 -(CH2)4 H C6H5 H OC6H5 CF3 H C2H5 H H C2H5 H I H F H CHO H CH2Cl H CF3 EXAMPLE 9 Preparation of diethyl furol3,2-¯]pyridine-5,6-dicarbo- xylate EMI45.1 3-Amino-2-formylfuran, prepared from 3-azido2-formylfuran (8.9 g 0.065 mol) is dissolved in ethanol and to this solution diethyl oxalacetate (12.23 g, 0.065 mol) and ten drops of piperidine are added. In addition pulverized 3AO molecular sieve is added and the reaction stirred at 65-600C for three hours, then additional diethyl oxalacetate (2.2 g) is added. The reaction is essentially complete after 12 hours at 55-600C. On cooling the reaction is filtered, and the filtrate concentrated and then dissolved in ethyl acetate, water washed, then brine washed, dried over anhydrous magnesium sulfate and stripped to dryness. The residue is dissolved in 3:1 hexane:ethyl acetate and passed through a flash chromatographic column in two stages. First it is filtered by vacuum through a four to five inch pad of silica from which the last three fractions containing the required product are collected and combined. These combined fractions are then passed through a six inch column eluting under pressure with ethyl acetate:hexane 3:1 and 2.1. Diethyl furo[3,2-b]pyridine-5,6-dicarboxylate 4.15 g (24%) is obtained after crystallization from hexane-ether, of mp 60-640C, and with a mass spectrum m/e of 264. Utilizing the above procedure and substituting the appropriate furan for 3-amino-2-formylfuran yields the compounds illustrated below. EMI46.1 Y Z R mp C H H C2H5 60-64 H Cl C2H5 CH3 H C2H5 H CH3 C2H5 C2H5 H C2H5 H C2H5 C2H5 CH3 CH3 C2H5 EXAMPLE 10 Preparation of furo[3,2-b]pyridine-5,6-dicarboxylic acid EMI47.1 Furo[3,2-b]pyridine-5,6-dicarboxylic acid, diethyl ester (1.1 g, 0.0042 mol) is dissolved in 95% ethanol (20 mL) containing 10% aqueous sodium hydroxide (20 mL) and set aside at D C for two days. The mixture is cooled, acidified and the solvent removed under reduced pressure. Water 5 mL is added and the hydrated product diacid obtained as a brown solid by filtration, 3.31 g (99%), mp 1830C (dec). Anal calcd. as C9H5N05e2 1/2 H20 C, 42.86; H,3.99; N,5.55 found: C,42.63; H, 2.63; N,5.46. Utilizing the above procedure and substituting the appropriate furo[3,2-b]pyridine-5,6-dicarboxylic ester yields the compounds illustrated below. Y Z R mpOC H H H 183 (dec) H Cl C2H5 CH3 H C2H5 H CH3 C2H5 C2H5 H C2H5 H C2H5 C2H5 CH3 CH3 C2H5 EXAMPLE 11 Preparation of furo[3,2-b]pyridine-5,6-dicarboxylic acid anhydride EMI48.1 Furo[3,2-b]pyridine-5,6-dicarboxylic acid (3.3 g, 0.0159 mol) in acetic anhydride (100 mL) is heated to 70-8O0C for six hours. The reaction mixture is cooled, filtered and the solid is washed with ether to give 3.01 (1005) of crude furo[3,2-b]pyridine-5,6- dicarboxylic acid anhydride. Utilizing the above procedure and substituting the appropriate furo[3,2-b]pyridine-5,6-dicarboxylic acid yields the compounds illustrated below. Y Z mp C H H H Cl CH3 H H CH3 C2H5 H H C2H5 CH3 CH3 EXAMPLE 12 Preparation of 5-[(1-carbamoyl-1,2-dimethylpropyl)carbamoyl]furo[3,2-b]pyridine-6-carboxylic acid and 5-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)furo [3,2-k]pyridine-6-carboxylic acid EMI49.1 Furo[3,2-bjpyridine-5,6-dicarboxylic acid anhydride (3.01 g, 0.015 mol) is suspended in THF (100 mL) to which 2-amino-2,3-dimethylbutyramide (2.3 g, 0.018 mol) is added. After stirring for 20 hours, the solution is stripped to an oily solid which dissolves in a water/dilute sodium hydroxide solution. The alkaline solution is extracted with methylene chloride, and then acidified and reextracted with methylene chloride but on stirring only minute traces of material is isolated. The water layer is concentrated to an oily solid which is dissolved in ethanol, filtered and concentrated to a purple gum which is predominantly the crude product, 5-[(1-carbamoyl-1,2-dimethylpropyl)- carbamoyl]furot3,2-b]pyridine-6-carboxylic acid and is used without further purification to prepare the final 2-imidazolin-2-yl product by dissolving it in 109 sodium hydroxide solution (40 mL) and warming at 800C for three hours. On cooling the reaction is acidified and a small amount of solid precipitated out and was filtered off. Concentration of mother liquors gives a second crop, which is collected and combined with the first crop. Purification is effected by taking half of the material and separating on silica gel preparative glass plates as bands. The slower running band using methylene chloride:ethyl acetate:chloroform: methanol 1:1:1:1 as eluant, affords the desired 2-imidazolin-2yl product, mp 214-2230C(dec), Esters may then be prepared by the procedures described in Example 20. Utilizing the above procedure and substituting the appropriate furo[3,2-b]pyridine-5,6-dicarboxylic anhydride yields the compounds illustrated below. EMI51.1 Y Z mp C H H 214-223 (dec) H C1 CH3 H H CH3 C2H5 H H C2H5 CH3 CH3 EXAMPLE 13 Preparation of dimethyl thieno[2,3-b]pyridine-5,6-dicar boxylate EMI52.1 A Vilsmeier reagent is prepared by adding dropwise, with stirring, phosphorus oxychloride (40.29 g, 0.26 mol) to a cooled (100C) solution of DMF (19.0 g, 0.26 mol) in 1,2-dichloroethane (40 mL) in an N2 atmosphere. This reagent is stirred at room temperature for one hour and 45 minutes. Dimethyl-2-thienylaminobutenedioate (63.4 g, 0.26 mol) dissolved in 1,2dichloroethane (300 mL) is added dropwise to the Vilsmeier reagent at 7-100C. The reaction temperature is raised to room temperature for 15 minutes, then to reflux for 12 hours. The cooled reaction mixture is concentrated and the residue chromatographed on a silica gel column with ethyl acetate-hexane, affording dimethylthieno[ 2,3-b]pyridine-5,6-dicarboxylate (29 g, 45X) as a solid. Utilizing the above procedure and substituting the appropriate dimethyl-2-th ienylaminobutened ioate yields the compounds illustrated below. EMI53.1 Y Z mp C CH3 H 80-82 H H 80-81 H CH3 CH3 CH3 H C6H5 C6H5 H CF3 H -(CH2)4- 118-121.5 EXAMPLE 14 Preparation of dimethyl 3-bromothieno[2,3-b)pyridine- 5, 6-dicarboxylate EMI54.1 Bromine (0.33, 0.00206 mol) in acetic acid (8 mL) is added to a stirred solution of dimethyl thienot2,3-b3pyridine-5,6-dicarboxylate (0.5 g, 0.00187 mol) in acetic acid containing sodium acetate (0.31 g, 0.00377 mol) at 400C. The reaction mixture is heated at 750C for 18 hours. Evaluation of the mixture by tlc (silica gel) indicated incomplete reaction. Additional bromine (0.33 g) in acetic acid and sodium acetate (0.31 g) is added and heating at 750C continued for six hours. The reaction mixture is diluted with water and extracted into ethyl acetate. The separated organic layer is dried over anhydrous MgSO4, filtered, and the filtrate concentrated to an oil which solidifies on standing. Crystallization of the crude product from ethyl acetate-hexanes yields the dimethyl 3-bromothieno [2,3-b}pyridine-5,6-dicarboxylate as white needles mp 86-87. 50C. This compound may be readily converted to a variety of substituted-thienot2,3-b}pyridine compounds as illustrated below, while electrophilic substitution such as nitration or halogenation yields additional compounds listed below. EMI55.1 Y Z mp C H H H Cl 104-110 H Br 86-87.5 H I H F H CN H SCH3 H OCH3 H N(CH3)2 H OCHF2 H NO2 H CHO H CH2Cl CH3 H 80-82 H CH3 oil Cl H Cl Cl 84-89 CH3 CH3 H S02N(CH3)2 -(CH2)4- 118.5 - 121.5 -(CH)4 -(CH2)3 C6H5 H H C6HS H OC6H5 CF3 H H SC6H5 H CF3 C2H5 H H C2H5 EXAMPLE 15 Preparation of thieno[2,3-b)pyridine-5,6-dicarboxylic acid EMI56.1 A solution containing dimethyl thienol2,3-b3- pyridine-5,6-dicarboxylate (27.75 g, 0.11 mol) and potassium hydroxide (30.98 g, 0.55 mol) in methanol (200 mL) under a N2 atmosphere is heated at reflux for two hours. The reaction mixture is cooled and sufficient water added to dissolve any solids present before evaporating the mixture to dryness. The resulting solid is dissolved in a minimum volume of water, cooled in an ice bath and acidified with concentrated H2S04 to pH¯l. Thienol2,3-blpyridine-5,6-dicarboxylic acid is filtered off and dried overnight to give 23.36 g mp 272-2750C. Utilizing the above procedure and substituting the appropriate substituted dialkylthienot2,3-b}- pyridine-5,6-dicarboxylate yields the compounds illustrated below. EMI57.1 Y Z mp C H H 272-275 H Cl > 300 H Br > 315 H I H F H CN H SCH3 H OCH3 H N(CH3)2 H OCHF2 H N02 H CHO H CH2Cl H CH3 180-183 (dec) CH3 H Cl H Cl Cl CH3 CH3 C6H5 H H SO2N(CH3)2 -(CH2)3 -(CH2)4- 280-290 -(CH)4 H OC6H5 H C6H5 CF3 H H CF3 H SC6H5 C2H5 H H C2H5 EXAMPLE 16 Preparation of thieno[2,3-b]pyridine-5,6-dicarboxylic snhydride EMI58.1 Acetic anhydride (37.4 g, 0.366 mol) is added to a stirred suspension of thieno[2,3-b]pyridine-5,6- dicarboxylic acid (21.52 g, 0.096 mol) in dimethoxyethane (175 mL) in an inert N2 atmosphere. Upon addition of pyridine (16.78 g, 0.21 mol) at room temperature an exotherm to 450C is observed and a homogeneous solution results. The reaction mixture is then stirred at room temperature and the resulting solid filtered off, washed with ether and air dried to give 14.8 g (752) of thienol2,3-b]pyridine-5,6-dicarboxylif acid ,snhydride. Utilizing the above procedure and substituting the appropriate substituted thienot2,3-b3pyridine-5,6- dicarboxylic acid yields the compounds illustrated below. EMI59.1 Y Z mp C CH3 H 176-180 H Br 228.5-231 H Cl 230-300 (slow dec) H H 210-213 H I H F H (:N H SCH3 H N(CH3)2 H N02 H CHO H CH2Cl H CH3 Cl H Cl Cl CH3 CH3 C6H5 H H S02N(CH3)2 -(CH2)3 -(CH2)4- 220-222 -(CH)4 H C6HS H OC6H5 CF3 H H CF3 H OCHF2 H SC6H5 H OCH3 C2H5 H H C2H5 EXAMPLE 17 Preparation of 6-[(1-carbamoyl-1,2-dimethylpropyl)carbamoyl]thieno[2,3-b]pyridine-5-carboxylic acid EMI60.1 2-Amino-2,3-dimethylbutyramide (9.84 g, 0.076 mol) is added to a stirred suspension of thieno [2,3-b3pyridine-5 7 6-dicarboxylic acid anhydride (14.8 g, 0.072 mol) in THF under an inert atmosphere of N2 at room temperature. The dark solution is stirred at room temperature overnight and the resulting solid filtered off, washed with THF and air dried to give 17.35 g (72%) of 6-[(1-carbamoyl-1,2-dimethylpropyl)carbamoyl]thieno[2,3-b]pyridine-5-carboxylic acid. Utilizing the above procedure and substituting the appropriate substituted thieno[2,3-bjpyridine-5,6- dicarboxylic acid anhydride yields the compounds illustrated below. EMI61.1 Y Z mp C CH3 H 207-208 H Br 176-178 H Cl 156-158 H H H I H F H CN H SCH3 H OCH3 H N(CH3)2 H N02 H CHO H CH2Cl H CH3 Cl H Cl Cl CH3 CH3 C6H5 H H SO2N(CH3)2 -(CH2)3 -(CH2)4- solid -(CH)4 H C6H5 H OC6H5 CF3 H H OCHF2 H CF3 H SC6H5 C2H5 H H C2H5 EXAMPLE 18 Preparation of 6-(5-isopropyl-5-methyl-4-oxo-2-imidazo lin-2-yl)thieno[2,3-blpyridine-5-carboxylic acid EMI62.1 6-[(1-Carbamoyl-1,2-dimethylpropyl)caramoyl] thieno[2,3-blpyridine-5-carboxylic acid (17.35 g, 0.052 mol) is added to water (225 mL) containing sodium hydroxide (10.35 g, 0.26 mol). The resulting basic solution is heated at 800C for two hours and 45 minutes, cooled in an ice-water bath and acidified with 6N H2S04. The product 6-(5-isopropyl-5-methyl-4-oxo-2-imidazolin2-yl)thieno[2,3-b]pyridine-5-carboxylic acid is filtered off, washed with water and air dried yielding 1.54 g, 70.37o, mp 221-2230C. EXAMPLE 19 Preparation of 5H-Imidazol1',2':1,2]pyrrolol3,4-b]- thieno[3,2-lpyridine-3(2q),5-dione, 2-isopropyl-2methyl EMI63.1 Dicyclohexylcarbodiimide (1.07 g, 0.005 mol) in methylene chloride (20 mL) is added dropwise to a stirred methylene chloride (30 mL) suspension of 6 (5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)thieno [2,3-b3-5-carboxylic acid (1.5 g, 0.0047 mol) under an N2 atmosphere. After stirring the reaction mixture for 16 hours, it was clarified by filtration, concentrated to dryness and the resulting material purified by column chromatography on silica gel eluting with acetonitrilel methylene chloride (1/2). The solid product was crystallized from toluene to give the pure 3,5-dione as white crystals mp 214.5-216.50C. EXAMPLE 20 Preparation of 2-propynyl 6-(5-isopropyl-5-methyl-4-oxo2-imidazolin-2-yl)thieno[2,3-blpyridine-5-carboxylate EMI64.1 Sodium hydride (2.4 g, 60X, 0.126 mol) is added to the 3,5-dione (0.9 g, 0.003 mol) in propargyl alcohol (25 mL) at IOOC under an inert N2 atmosphere. The reaction mixture is stirred at room temperature for 60 hours and then neutralized with a saturated ammonium chloride solution. The resulting mixture is concentrated on a rotary evaporator, diluted with water and extracted with ethyl acetate. The organic layer is separated, dried over anhydrous MgS04 and concentrated to dryness. Purification of the product by column chromatography on silica gel with methylene chloridelacetoni- trile (85/15) yields 2-propynyl 6-(5-isopropyl-5-methyl4-oxo-2-imidazolin-2-yl)pyridine-5-carboxylate, which after crystallization from toluene has a mp 188-189.50C. Utilizing the procedures of Examples 18, 19 and 20 and substituting the appropriate thieno [3,2-b]pyridine or thieno [2,3-b]pyridine compounds, yields the compounds illustrated below. EMI65.1 EMI65.2 <tb> Y <SEP> Z <SEP> RX <SEP> mpOC <tb> H <SEP> H <SEP> CH3 <SEP> 215-217 <tb> H <SEP> H <SEP> H <SEP> 220-223.5 <tb> <SEP> (dec) <tb> H <SEP> H <SEP> -CH2C=CH <SEP> 188-189.5 <tb> H <SEP> H <SEP> II <SEP> 140-142 <tb> <SEP> -CH2 <tb> <SEP> 0 <tb> H <SEP> H <SEP> -CH2'CH2 <SEP> 108-110 <tb> CH3 <SEP> H <SEP> H <SEP> 225.5-227.5 <tb> H <SEP> Br <SEP> H <SEP> 274-276 <tb> H <SEP> C1 <SEP> H <SEP> 266-267 <tb> H <SEP> N02 <SEP> -CH3 <SEP> 201-202.50C <tb> H <SEP> NO2 <SEP> H <SEP> 260 <SEP> (dec) <tb> C1 <SEP> H <SEP> H <tb> C1 <SEP> C1 <SEP> H <tb> H <SEP> CH3 <SEP> H <tb> H <SEP> N(CH3)2 <SEP> H <tb> Y Z R3 mp C H SCH3 H H OCH3 H H OCHF2 H CH3 CH3 H H CN H H S02N(CH3)2 H C6H5 H H H C6H5 H -(CH2)3- H -(CH2)4- H -(CH2)4- H H OC6H5 H CF3 H H C2H5 H H H C2H5 H H I H H F H H CHO H H CH2Cl H H CF3 H H SC5H6 H EMI67.1 EMI67.2 <tb> Y <SEP> Z <SEP> R3 <SEP> mpOC <tb> H <SEP> H <SEP> H <SEP> 242-244 <tb> H <SEP> C1 <SEP> H <SEP> 238-239 <tb> H <SEP> Br <SEP> H <SEP> 226-227 <tb> H <SEP> H <SEP> m <SEP> 156-157 <tb> <SEP> CH2 <tb> C1 <SEP> H <SEP> H <SEP> 266-267 <tb> C1 <SEP> I <SEP> H <tb> H <SEP> CH3 <SEP> H <tb> H <SEP> F <SEP> H <tb> CH3 <SEP> H <SEP> H <tb> C1 <SEP> C1 <SEP> H <tb> H <SEP> NO2 <SEP> H <tb> H <SEP> N(CH3)2 <SEP> H <tb> H <SEP> SCH3 <SEP> H <tb> H <SEP> OCH3 <SEP> H <tb> CH3 <SEP> CH3 <SEP> H <tb> H <SEP> CHO <SEP> H <tb> H <SEP> OCHF2 <SEP> H <tb> H <SEP> CN <SEP> H <tb> H <SEP> S02N(CH3)2H <tb> C6H <SEP> H <SEP> H <tb> H <SEP> C6H5 <SEP> H <tb> Y Z R3 mp C -(CH2)3- H -(CH2)4- H -(CH2)4- H H OC6H5 H CF3 H H H CF3 H C2H5 H H H C2H5 H H CH2Cl H H SC6H5 H EXAMPLE 21 Preparation of methyl 6-(4-isopropyl-4-methyl-5-oxo-2- imidazolin-2-yl) -3-nitrotbieno[2,3-]pyridine-5-carboxy- late EMI69.1 Methyl 6-(4-isopropyl-4-methyl-5-oxo-2 imidazolin-2-yl)thieno[2,3-b]pyridine-5-carboxylate (3.94 g, 0.0115 mol) is dissolved in 200 mL concentrated H2S04 at room temperature. While cooling to 30C in an ice bath, 1.5 mL (0.024 mol) concentrated HN03 is added, then the mixture is allowed to warm to room temperature. After three hours, the reaction mixture is poured onto ice, neutralized with solid NaHC03 to pH 6 and is extracted with methylene chloride. The extract is filtered, then dried over sodium sulfate, refiltered and concentrated to a yellow solid weighing 4.33 g (97%), which upon crystallization from methanol water has mp 20l-202.50C. EXAMPLE 22 Preparation of 6-(4-isopropyl-4-methyl-5-oxo-2-imidazo- lin-2-yl)-3-nitrothieno[2,3-Jpyridine-5-carboxylic acid EMI70.1 The ester (1.0 g, .00266 mol) from Example 21 is stirred in 100 mL methanol and 10 mL 10% sodium hydroxide solution for 24 hours. Water (25 mL) is added and the methanol removed in vacuo. Acidification of the aqueous layer gives a brown precipitate which upon filtration and crystallization from methanol-water has mp 2600C. EXAMPLE 23 Preparation of diethyl 5-acetyl-1,6-dihydro-6-oxo-2,3- pyridinedicarboxylate EMI71.1 Sodium acetate (30 g, 0.37 mol) is added to a stirred mixture of diethyl(ethoxymethylene)oxalacetate (87 g, 0.36 mol) and acetoacetamide (36 g, 0.36 mol) in absolute ethanol (300 mL). After stirring the reaction mixture for 30 minutes, the ethanol is distilled off under reduced pressure, the residue acidified to pH 2 with dilute aqueous hydrochloric acid and the resulting solid filtered off. Crystallization from an ethanol-water mixture affords diethyl 5-acetyl l,6-dihydro-6-oxo-2,3-pyridinedicarboxylate as crystals mp 101-110OC. EXAMPLE 24 Preparation of isobutyryl acetonitrile EMI72.1 NaH (61.55 g of 6Q% dispersion, 1.54 mol) is added to 650 mL anhydrous THF under N2. The suspension is heated to reflux. Methyl isobutyrate (100 g, 98 mol) and acetonitrile (63.16 g, 1.54 mol) are mixed in 140 mLs anhydrous THF and added dropwise over one hour to the refluxing suspension. The resulting solution is refluxed for 16 hours. Enough water is added to the reaction mixture to dissolve the salt that is formed. The THF is removed in vacuo, and the basic aqueous solution is extracted with ether, then acidified to pH 4 with concentrated HCl. The solution is extracted with ether. The extracts are washed with brine and dried over anhydrous MgS04, filtered and the solvent is removed in vacuo, giving 97.25 g, (89.4%) of the title product an orange oil. EXAMPLE 25 Preparation of diethyl-5-(2-methylpropionyl)-1,6-dihydro-6-oxo-2,3-pyridinedicarboxylate EMI73.1 Isobutyl acetonitrile (50 g, 0.45) 24 and diethyl(ethoxymethylene)oxalacetate (110 g, 0.45 mol) are dissolved in absolute ethanol and then is added sodium acetate (36.9 g, 0.45 mol) and one drop of piperidine. After 12 hours, the mixture is concentrated, acidified with dilute hydrochloric acid then extracted with methylene chloride. The extracts are concentrated and recrystallized to give the title product as a white solid 21.7 g (19.5%) mp 116-1180C. EXAMPLE 26 Preparation of diethyl 5-(bromoacetyl)-1,6-dihydro6-oxo-2, 3-pyridinedicarboxylate EMI74.1 Bromine (8.0 g, 0.050 mol) in 48% HBr is added dropwise to a stirred solution of diethyl-5 acetyl-l,6-dihydro-6-oxo-2,3-pyridinedicarboxylate (14.05 g, 0.05 mol) in 48% HBr t200 mL). Upon completion of this bromine addition the reaction mixture is poured onto ice (200 g) and the mixture is stirred until the ice has melted. The crude product is collected by filtration and crystallized twice from an ethyl acetate-hexane mixture (1/2) affording diethyl 5-(bromoacetyl)-l,6-dihydro-6-oxo-2,3-pyridinedicarbo- xylate with mp 141-l420C. Utilizing the the above procedure using diethyl 2-methylpropionyl-2-pyridone-dicarboxylate yields diethyl 5-(2-bromo-2-methylpropionyl)-1,6-dihydro-6-oxo-2,3- pyridinedicarboxylate, mp l24-1260C. EXAMPLE 27 Preparation of diethyl 5-(2-bromo-1-hydroxyethyl)-1,6dihydro-6-oxo-2,3-pyridinedicarboxylate and diethyl 2,3-dihydro-3-hydroxy-furol2,3-blpyridine-5,6-dicarbo- xylate EMI75.1 Sodium borohydride (2.54 g, 0.066 mol) is added in portions over a 30 minute period to a stirred suspension of diethyl 5-(bromoacetyl)-1,6-dihydro-6- oxo-2,3-pyridinedicarboxylate (57.2 g, 0.159 mol) at 10-200C. Upon completion of the sodium borohydride addition, the reaction mixture is stirred while attaining room temperature. Ice (100 g) is added and the mixture stirred until the ice has melted. The mixture is then concentrated in vacuo and the residue crystallized twice from an ethyl acetate-hexane mixture to give pure diethyl 5-(2-bromo-1-hydroxyethyl)-1,6- dihydro-6-oxo-2,3-pyridinedicarboxylate mp 134-1380C. Stirring this compound with triethylamine (1.0 mL/g of solid) in methylene chloride for one hour, followed by washing the organic solution with dilute hydrochloric acid, water, brine and drying over anhydrous MgS04 yields the crude furo[2,3-b]pyridine as an oil upon removing the solvent in vacuo. Crystallization from a cyclohexane-toluene mixture affords pure diethyl 2,3dihydro-3-hydroxy-furo[2,3-b]pyridine-5,6-dicarboxylate mp 73-770C. EXAMPLE 28 Preparation of diethyl 2,3-dihydro-3-methoxyfuro[2,3-b]pyridine-5, 6-dicarboxylate EMI77.1 Sodium hydride, 60% dispersion in mineral oil (2.05 g, 0.0512 mol) and iodomethane (7.9 mL, 0.128 mol) are added to a solution of the hydroxy diester of Example 27 (12.00 g, 0.0427 mol) in tetrahydrofuran (400 mL) under N2. After stirring overnight at room temperature, the reaction is heated to 500C under a stream of N2 to remove excess iodomethane. The reaction is then cooled, filtered, stripped and chromatographed over silica gel. Eluting with hexane/ethyl acetate (4:1) gives the product as a yellow oil in 57.3% yield. Calcd. for C14H17N06; C, 56.94; 4,5.80, N, 4.74. Found: C, 56.93; H, 5.59; N, 4.83. EXAMPLE 29 Preparation of diethyl furo[2,3-X3pyridine-5,6-dicarbo- xylate EMI78.1 A xylene solution of the hydroxy-furo compound obtained in Example 23, (3.7 g) containing paratoluene sulfonic acid (0.01 g) is heated at reflux for two hours. The solution is cooled and the xylene solution decanted off. The residue is extracted with ether and the extracts combined with the xylene. Distillation of the solvents gives a yellow solid which is crystallized from a cyclohexane-toluene mixture to give pure diethyl furo[2,3-b3pyridine-5,6-dicarboxylate mp 66-770C. EXAMPLE 30 Preparation of dimethyl 2-methyl-furol2,3-¯lpyridine- 5, 6-dicarboxylate EMI79.1 Propyne (3.0 mLs,0.045 mol) is condensed in a graduated cylinder in a dry ice/acetone bath and added to a stirred suspension of dimethyl 1,6-dihydro-5-iodo 6-oxo-2,3-pyridinedicarboxylate (13.48 g,0.04 mol), cuprous iodide (0.38 g, 0.002 mol) and bis(triphenylphosphine)palladium II) chloride (2.81 g,O.004 mol) in 150 mLs DMSO and 50 mLs triethylamine at lO0C. After addition of the propyne the reaction mixture is stirred at room temperature for 60 hours. Water is added and the mixture is extracted with ethyl acetate. The ethyl acetate solution is washed with water and dried over anhydrous MgS04, then concentrated in vacuo to give a mixture of materials. The crude product is isolated by flash column chromatography using 9:1 methylene chloride: ethyl acetate. The fractions containing the title product are concentrated in vacuo and the residue is recrystallized from cyclohexane to give the pure compound mp 115-118oC. Utilizing the above procedure and substituting the appropriate substituted acetylene yields the compounds illustrated below. EMI80.1 R mp C C2H5 147-149 Phenyl 152-153 EXAMPLE 31 Preparation of diethyl 2,3-dihydro-3,3-dimethylfuro- [2, 3-b] pyridine-5 , 6-dicarboxylate EMI81.1 The 5-(2-bromo-2-methylpropy ketone diester of Example 26 (20 g, 0.052 mol) is dissolved in 200 mL absolute ethanol and 3.0 g sodium borohydride (0.078 mol) is added at OOC, the temperature is then allowed to rise gradually to 150C. After the mixture is stirred for one additional hour, the ethanol is removed in vacuo. The solidified mass is treated with water and extracted with methylene chloride. The organic extract is then washed with water and a saturated sodium chloride solution, dried and concentrated. The residue, weighing 12 g is redissolved in xylene and 1.0 g p-toluenesulfonic acid is added. The solution is refluxed for 12 hours then cooled. The xylene solution is decanted and the residue washed with several portions of ether. The combined organic solutions are concentrated then chromatographed with 9:1 methylene chloride/ethyl acetate to obtain 3.2 g of the oily diester (21%); mass spectrum M + l/e = 294. From a later chromatographic fraction is obtained 1.4 g of 2,2-dimethyl-3-hydroxyfuro[2,3-b]pyridine-5,6-dicarboxylate (11.5%). EXAMPLE 32 Preparation of diethyl 3-bromofuro[2,3-b]pyridine-5,6- diarboxylate EMI83.1 The diester of Example 29 (6.0 g, 0.0228 mol) is dissolved in 200 mL methylene chloride containing 4.6 g sodium acetate, and bromine is added (7.3 g, 0.0556 mol) at reflux. Following the addition, the mixture was stirred for 15 minutes at reflux, then cooled, washed with aqueous sodium bisulfite, dried with sodium sulfate and filtered. The filtrate was stripped to 8.8 g of the crude dibromo compound which was redissolved in methylene c hloride and treated with 3.16 g DBU (0.021 mol) at room temperature for 30 minutes. The mixture was then concentrated in vacuo, and chromatographed over silica gel with hexaneethylacetate to give 7.1 g (90%) of the diethyl 3-bromofuro[2,3-b]pyridine-5,6-dicarboxylate mono bromo diester mp 49.5-520C. EXAMPLE 33 Preparation of diethyl 2,3-dibromofuro[2,3-b]pyridine- 5,6-dicarboxylae EMI84.1 Sodium acetate (2.40 g, 0.0292 mol) and bromine (7.5 mL, 0.146 mol) are added to a solution of diethyl 3-bromofuro[2,3-b]pyridine-5,6-dicarboxylate (5.00 g, 0.0146 mol) in methylene chloride (150 mL). The mixture is stirred at room temperature for four days then washed with aqueous sodium bisulfate to remove unreacted bromine. The aqueous solution is then back extracted with methylene chloride. The organic solution is combined, dried over sodium sulfate and filtered. To the filtrate is added 1,8-diazabicyclo 15.4.0]undec-7-ene(4.4 mL, 0.032 mol), and the mixture is stirred at room temperature for one hour. The solution is then concentrated in vacuo. The residue is chromatographed over silica gel eluting with 202 ethyl acetate in hexane, yielding the crude 2,3-dibromofuro [2,3-b]pyridine as a white solid in 95% yields recrystallization from a methylene chloride-hexane mixture affords diethyl 2,3-dibromofuro[2,3-b3pyridine-5,6-dicarboxylate mp 96-980C in 75.9% recrystallized yield. EXAMPLE 34 Preparation of diethyl 3-trifluoromethylfuro[2,3-b]pyridine-5, 6-dicarboxylate EMI86.1 To a solution of sodium trifluoroacetate (0.0234 mol) in N-methylpyrrolidone (50 mL) is added 3-bromofuropyridine of Example 32 (2.02, 0.00585 mol) and cuprous iodide (2.2 g, 0.0119 mol). The mixture is heated to 1600C for three hours under N2, cooled to room temperature, treated with EtOAc (100 mL) and hexene (100 mL), and filtered. The filtrate is washed with H20 (4x200 mL), dried over Na2SO4 and stripped to an oil which is chromatographed over silica gel with hexane-ETOAc (7:3) elution. The product is collected as a pale yellow solid; mp 50-550C. EXAMPLE 35 Preparation of furo[2,3-hlpyridine-5,6-dicarboxylic acid EMI87.1 Potassium hydroxide (5.60 g, 85, 0.087 mol) in water (5 mL) is added to a stirred suspension of diethyl furo[2,3-b]pyridine-5,6-dicarboxylate (9.3 g, 0.035 mol) in absolute ethanol (100 mL). The reaction mixture is heated at 600C for one hour, then cooled and anhydrous acetone added. The precipitate is filtered off, dried, suspended in dry acetone and treated with hydrogen chloride to adjust to a pH of 2. Crystallization of the isolated solids from an ethyl acetateacetone mixture affords furo[2,3-b]pyridine-5,6-dicar- boxylic acid mp 189-1920C. EXAMPLE 36 Preparation of furo[2,3-b)pyridine-5,6-dicarboxylic anhydride EMI88.1 Furot2,3-blpyridine-5,6-dicarboxylic acid (6.7 g, 0.032 mol) is heated at 600C for 30 minutes in acetic anhydride (150 mL). The reaction mixture is cooled to room temperature and concentrated in vacuo and the residue triturated with cyclohexane-ether(5:1), filtered off and dried to give 5.35 g furot2,3-b]- pyridine-5,6-dicarboxylic acid anhydride. EXAMPLE 37 Preparation of 6-[(1-carbamoyl-1,2-dimethylpropyl)- carbamoyl]-furo[2,3-blpyridine-5-carboxylic acid EMI89.1 2-Amino-2,3-dimethylbutyramide (2.1 g, 0.016 mol) is added to a stirred suspension of furo [2,3-b]pyridine-5,6-dicarboxylic acid anhydride (3.0 g, 0.016 mol) in tetrahydrofuran (7.5 mL) and the mixture allowed to stir at room temperature for 16 hours. The reaction mixture is then stirred at 6O0C for one hour, cooled to room temperature, ether added, and the solid filtered off and dried to give 5 g of 6-[(1-carbamoyl- 1,2-dimethylpropyl)carbamoylifuro[2,3-b]pyridine-5- carboxylic acid mp 192-1960C (dec). EXAMPLE 38 Preparation of 6-(4-isopropyl-4-methyl-5-oxo-2-imidazo lin-2-ylifurol2,3-blpyridine-5-carboxylic acid EMI90.1 A solution containing 6-t(1-carbamoyl-1,2- dimethylpropyl)carbamoyllfuro[2,3-b]pyridine-5-carbo- xylic acid (3.8 g, 0.012 mol) in aqueous sodium hydroxide 2.4 g, 0.06 mol) in water (40 mL) is stirred at 650C for three hours. The reaction mixture is then heated at 750C for one hour, allowed to cool, poured into ice, acidified to pH 2-3 and the resulting solid filtered off and dried. Crystallization from an acetone-methanol mixture affords pure 6-(4-isopropyl-4 methyl-5-oxo-7-imidazolin-2-yl)furol2,3-blpyridine-5- carboxylic acid mp 237-2440C EXAMPLE 39 Preparation of 6-[4-isopropyl-4-methyl-5-oxo-2-imidazo lin-2-yl)-3-nitrofuro[2,3-h]pyridine-5-carboxylic acid EMI91.1 Nitryl hexafluorophosphate (0.75 g, 0.00391 mol) is added to a suspension of 6-(4-isopropyl-4-methyl-5 oxo-2-imidazolin-2-y1)-furo[2,3-b]pyridine-5-carboxylic acid (1.07 g, 0.00355 mol) in sulfolane (63 mL) under nitrogen. The temperature of the reaction is maintained between 640C and 850C for three days during which time the solids dissolve. The mixture is cooled to 300C and chromatographed over silica gel. Elution with 1:1 hexane to ethyl acetate removes the sulfolane. Elution with 1% to 10% methanol in methylene chloride followed by recrystallization from acetone-hexane yields 6-(4-isopropyl-4-methyl-5-oxo-2-imidazol yl)-3-nitro-furo[2,3-b]pyridine-5-carboxylic acid, mp 220-2370C. EXAMPLE 40 Preparation of 2-isopropyl-2-methyl-5H-furo[2,3-b]imidazo[2',1':5,1]pyrrolo[3,4-e]pyridine-3(2H),5-dione EMI92.1 To a suspension of 6-(4-isopropyl-4-methyl S-oxo-2-imidazolin-2-yl)-furo[2,3-b]-pyridine-5-car- boxylic acid (11.7 g, 0.039 mol) in 100 mL dimethoxyethane (DME) is added 7.3 mL acetic anhydride and 3.9 mL pyridine. After stirring 24 hours at room temperature, the solids are filtered and washed with ether and the mother liquor is concentrated by adding xylene to aid removal of pyridine. The residue is triturated with ether to obtain solids which are combined with the first crop to give 11.1 g (100:) of product. Recrystallization from 2:1 ethyl acetatehexane gives an analytical sample mp 193-2050C. EXAMPLE 41 Preparation of methyl 6-(4-isopropyl-4-methyl-5-oxo-2- imidazolin-2-yl)-furot2,3-bZpyridine-5-carboxylate EMI93.1 The compound prepared in Example 40 (10.5 g, 0.037 mol) is suspended in 150 mL absolute methanol and 4.0 g sodium methoxide is added. After stirring for 72 hours at room temperature the mixture is poured onto ice containing acetic acid to maintain the pH at 3-4. A white solid forms and is filtered yielding 9.8 g (84%) of the title compound with mp 134-1370C. EXAMPLE 42 Preparation of methyl 3-chloro-6-(4-isopropyl-4-methyl 5-oxo-2-imidazolin-2-yl)-furo[2,3-ipyridine-5-carboxylate EMI94.1 The methyl ester described in Example 40 is dissolved (1.4 g, 4.4 mmol) in 20 mL acetic acid and sodium acetate (1.0 g, 12.2 mmol) is added. Gaseous chlorine is passed into the stirred solution for two hours during which time the temperature reaches 400C. After cooling and pouring onto 50 g ice, the mixture is extracted with ethyl acetate, washed with distilled water then with saturated sodium carbonate solution. The organic layer is then concentrated to a foam, redissolved in 20 mL methylene chloride and treated with 10 mL diazabicyclo-[5.4.0]undec-5-ene (DBU). After ten minutes, the mixture is treated with 20 mL cold dilute hydrochloric acid. The methylene chloride layer is removed, dried over anhydrous magnesium sulfate. The solution is then passed through a one-quarter inch pad of silica gel and concentrated in vacuo. Recrystallization from hexane-ethyl acetate gives 0.85 g (57%) of the 3-chloro compound mp 150-1560C. EXAMPLE 43 Preparation of 3-chloro-6-(4-isopropyl-4-methyl-5 oxo-2-imidazolin-2-y1)-furo[ 2,3-b]pyridine-5-carboxylic acid EMI95.1 The ester from Example 42 (0.55 g, 1.157 mmol) is dissolved in 10 mL 95% ethanol and 0.28 g 50% sodium hydroxide solution is added. After one hour the mixture is treated with 10% hydrochloric acid to pH 2, and the product separates as a solid, which is filtered, dried and recrystallized from acetone to give 0.35 g (67.3%) mp 239-2400C. EXAMPLE 44 Preparation of (+)-6-(4-isopropyl-4-methyl-5-oxo-2imidazolin-2-yl)-furo[2,3-b]pyridine-5-carboxylic acid EMI96.1 (+)-isomer Furo[2,3-b]pyridine-5,6-Dicarboxylic anydride (2.50 g, 0.013 mol) is suspended in 40 mLs anhydrous THF and (+)-2-amino-2,3-dimethylbutyramide (1.72 g, 0.013 mol) is added. The mixture is stirred under N2 at room temperature for 16 hours. The solution is poured into 150 mLs anhydrous ether, and the resulting solid is collected in 88.6% crude yield. The unpurified adduct is converted to the indicated product in the manner described in Example 38 for the racemic mixture. The (+)-isomer is recrystallized from absolute ethanol, and is isolated in 27.0% yield from the adduct.,mp 244-245 C [&alpha;]D25 = 44.5 . EXAMPLE 45 Preparation of sodium 6-(4-isopropyl-4-methyl-5-oxo-2 imidazolin-2-yl)furol2,3-b]pyridine-5-carboxylate EMI97.1 NaOH (0.13 g, .0033 mol) is dissolved in 50 mLs anhydrous methanol under N2. The free carboxylic acid (1.00 g, .0033 mol) is added, dissolving to give a yellow solution. The solvent is removed in vacuo to give a yellow oil. The oil is dissolved in anhydrous ethanol and the solvent removed in vacuo to give a solid. The solid is dissolved in anhydrous ethanol and reprecipitated with anhydrous ether, giving 0.60 g (56.1%) of the title sodium salt as a yellow solid, mp 240- > 2500C. EXAMPLE 46 Preparation of 6-(4-isopropyl-4-methyl-5-oxo-2-imidazo lin-2-yl)furo[2,3-bjpyridine-5-carboxylate, compound with isopropylamine (1:1) EMI98.1 Isopropylamine (0.25 mL, 0.00266 mol) is added to a suspension of the carboxylic acid (0.80 g, 0.00266 mL) and methanol (50 mL). The reaction is stirred at room temperature for one-half hour, during which time all the solids dissolve. The solvent is removed in vacuo, and the residue is slurried in ether and filtered, yielding the isopropyl amine salt in 78.1% yield, mp 100-2200C with slow decomposition. EXAMPLE 47 Preparation of imidazolin-2-yl thieno- and furopyridines Utilizing the procedures of the preceeding examples and substituting the appropriate thieno or furo[3,2-bjpyridine or thieno or furo[2,3-b]pyridine compounds, yields the compounds illustrated below. EMI99.1 EMI99.2 <tb> X <SEP> Y <SEP> Z <SEP> R3 <SEP> mpoC <tb> S <SEP> H <SEP> H <SEP> CH3 <SEP> 215-217 <tb> S <SEP> H <SEP> H <SEP> H <SEP> 220-223.5 <tb> <SEP> (dec) <tb> S <SEP> H <SEP> H <SEP> -CH2CECH <SEP> 188-189.5 <tb> S <SEP> H <SEP> H <SEP> H <SEP> 140-142 <tb> <SEP> KH22s <SEP> J <tb> <SEP> 0 <tb> <SEP> H3 <tb> S <SEP> H <SEP> H <SEP> -CH2 & CH2 <SEP> 108-110 <tb> S <SEP> CH3 <SEP> H <SEP> H <SEP> 225.5-227.5 <tb> S <SEP> H <SEP> Br <SEP> H <SEP> 274-276 <tb> S <SEP> H <SEP> C1 <SEP> H <SEP> 266-267 <tb> O <SEP> H <SEP> H <SEP> H <SEP> 237-244 <tb> S <SEP> H <SEP> N02 <SEP> CH3 <SEP> 201-202.5 <tb> S <SEP> H <SEP> NO2 <SEP> H <SEP> 260 <SEP> (dec) <tb> S <SEP> C1 <SEP> C1 <SEP> H <tb> S <SEP> H <SEP> N(CH3)2 <SEP> H <tb> S <SEP> H <SEP> SC6HS <SEP> H <tb> S <SEP> H <SEP> SCH3 <SEP> H <tb> S <SEP> H <SEP> OCH3 <SEP> H <tb> S <SEP> H <SEP> OCHF2 <SEP> H <tb> S <SEP> CH3 <SEP> CH3 <SEP> H <tb> S <SEP> H <SEP> CN <SEP> H <tb> EMI100.1 <tb> X <SEP> Y <SEP> Z <SEP> R3 <SEP> mpOC <tb> O <SEP> H <SEP> C1 <SEP> H <SEP> 239-240 <tb> O <SEP> H <SEP> H <SEP> CH3 <SEP> 134-137 <tb> O <SEP> H <SEP> Br <SEP> H <SEP> 239-245 <tb> o <SEP> CH3 <SEP> H <SEP> H <SEP> 174-177 <tb> O <SEP> C2H5 <SEP> H <SEP> H <SEP> 170-172 <tb> O <SEP> C6H5 <SEP> H <SEP> H <SEP> 244-245 <tb> S <SEP> C1 <SEP> H <SEP> H <SEP> 268 <SEP> (dec) <tb> O <SEP> H <SEP> C1 <SEP> CH3 <SEP> 137-141 <tb> S <SEP> H <SEP> CH3 <SEP> H <SEP> 255-257 <tb> S <SEP> -(CH2)4- <SEP> H <SEP> 234-237 <tb> O <SEP> H <SEP> CF3 <SEP> H <tb> O <SEP> H <SEP> SC6H5 <SEP> H <tb> O <SEP> H <SEP> H <SEP> -CH2'I <SEP> 137-141 <tb> O <SEP> H <SEP> H <SEP> -CH2CECH <SEP> 150-156 <tb> S <SEP> C1 <SEP> H <SEP> +NH3-CH(CH3)2 <SEP> Anal: : <tb> <SEP> ok <SEP> for <tb> <SEP> S <SEP> and <SEP> Cl <tb> S <SEP> H <SEP> S02N(CH3)2 <SEP> H <tb> S <SEP> C6H5 <SEP> H <SEP> H <tb> S <SEP> -(CH2)3- <SEP> H <tb> S <SEP> -(CH)4- <SEP> H <tb> S <SEP> H <SEP> C6H5 <SEP> H <tb> S <SEP> H <SEP> OC6H5 <SEP> H <tb> S <SEP> CF3 <SEP> H <SEP> H <tb> S <SEP> C2H5 <SEP> H <SEP> H <tb> S <SEP> H <SEP> C2H5 <SEP> H <tb> S <SEP> H <SEP> I <SEP> H <tb> S <SEP> H <SEP> F <SEP> H <tb> S <SEP> H <SEP> CHO <SEP> H <tb> S <SEP> H <SEP> CH2C1 <SEP> H <tb> S <SEP> H <SEP> CF3 <SEP> H <tb> O <SEP> H <SEP> N02 <SEP> H <SEP> 220-237 <SEP> (dec) <tb> X Y z R3 mp C O H N(CH3)2 H O H SCH3 H O H OCH3 H O C1 H H 0 Cl Cl H O H CH3 H O CH3 CH3 H O H OCHF2 H O H CN H O H S02N(CH3)2 H 0 -(CH2)4- H 0 -(CH2)3 - H O -(CH)4- H O H C6H5 H O H OC6H5 H O CF3 H H O H C2H5 H O H I H O H F H O H CHO H O H CH2C1 H EMI102.1 EMI102.2 <tb> X <SEP> Y <SEP> Z <SEP> R3 <SEP> rXp C <tb> S <SEP> H <SEP> H <SEP> H <SEP> 242-244 <tb> S <SEP> H <SEP> C1 <SEP> H <SEP> 238-239 <tb> S <SEP> H <SEP> Br <SEP> H <SEP> 226-227 <tb> S <SEP> H <SEP> H <SEP> m <SEP> 156-157 <tb> <SEP> --Cti2 <tb> <SEP> o <tb> O <SEP> H <SEP> H <SEP> H <SEP> 214-223 <tb> S <SEP> Cl <SEP> H <SEP> H <SEP> 266-267 <tb> O <SEP> H <SEP> Cl <SEP> H <tb> O <SEP> H <SEP> CH3 <SEP> H <tb> O <SEP> CH3 <SEP> H <SEP> H <tb> O <SEP> C2H5 <SEP> H <SEP> H <tb> O <SEP> H <SEP> C2H5 <SEP> H <tb> O <SEP> CH3 <SEP> CH3 <SEP> H <tb> S <SEP> H <SEP> CN <SEP> H <tb> S <SEP> H <SEP> CH3 <SEP> H <tb> S <SEP> CH3 <SEP> H <SEP> H <tb> S <SEP> CH3 <SEP> CH3 <SEP> H <tb> S <SEP> H <SEP> N02 <SEP> H <tb> S <SEP> H <SEP> N(CH3)2 <SEP> H <tb> S <SEP> H <SEP> SCH3 <SEP> H <tb> S <SEP> H <SEP> OCH3 <SEP> H <tb> S <SEP> H <SEP> OCHF2 <SEP> H <tb> S <SEP> Cl <SEP> C1 <SEP> H <tb> X Y Z R3 mp C S H S02N(CH3)2 H S C6H5 H ' H S H C6H5 H S -(CH2)3- H S -(CH2)4- H S -(CH)4- H S H OC6H5 H S CF3 H H S C2H5 H H S H C2H5 H S H I H S H F H S H CHO H S H CH2C1 H S H CF3 H S H SC6H5 H EXAMPLE 48 Preparation of 6-(4-isopropyl-4-methyl-5-thioxo-2-imida zolin-2-yl)-furo[2,3-]pyridine-5-carbox acid EMI104.1 5,6-Dicarboxylic anhydride-furo[2,3-b]pyridine (1.35 g, 0.0071 mol) is suspended in 25 mLs anhydrous ThF and 2-amino-2,3-dimethylthiobutyramide (1.04 g, 0.0071 mol) is added. The mixture is stirred under N2 at room temperature for three hours. The suspended solid is collected and the filtrate is stripped to a solid. The combined yield is 2.30 g (96.2%). Both solids are added together to KOH (1.91 g, 0.034 mol) in 20 mLs water. The solution is warmed to 600C for four hours, then stirred at room temperature for 16 hours. The slightly cloudy solution is filtered to give a clear filtrate, which is acidified to pH 4 with 10% HCl. The resulting yellow solid is collected and refluxed in 100 mLs xylene for 16 hours. The indicated product crystallized from the xylene solution in 28.0% yield, mp 231-2320C dec. In the same manner as described above for the furo[2,3-b]pyridine compound, 6-(4-isopropyl-4-methyl-5thioxo-2-imidazolin-2-yl)-thico[2,3-b]pyridine-5-carboxylic acid is prepared in 37% yield having a mp 2420C. EXAMPLE 49 Preparation of 2,3-dihydro-6-(4-isopropyl-4-methyl-5 oXo-2-imidazolin-2-yl)furol2,3-blpyridine-5-carboxylic acid EMI105.1 A solution of 6-(4-isopropyl-4-methyl-5-oxo-2- imidazolin-2-yl)furo[2,3-b]pyridine-5-carboxylic acid (1.7 g 0.056 mol) and 1.0 g (0.0072 mol) potassium carbonate in 200 mL 9:1 ethanol:water is added to 100 mg 5% palladium on carbon catalyst in a 500 mL pressure bottle. The bottle is fitted to a Parr hydrogenation apparatus, pressurized to 30 psi, with hydrogen, then shaken at room temperature for 10 hours. The catalyst is removed by filtration through a sintered glass funnel, and the filtrate concentrated in vacuo to 10 mL. Acidification of the residue to pH 2 gives a white precipitate which is removed by filtration, washed with water and air dried to give 1.0 g (632) of 2,3-dihydro6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)furo [2,3-b]pyridine-5-carboxylic acid as an off-white solid, mp 189-1920C. By the above procedure, a solution of 5-(4isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)furo[3,2-b]pyridine (400 mg) may be converted to 2,3-dihydro-5-(4isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)furo[3,2-b]pyridine-6-carboxylic acid, mp 205-206 C. EXAMPLE 50 Preparation of 4-mercaptoacetyl butyronitrile EMI107.1 Thiolacetic acid (49 mL, 0.69 mol) is added to potassium carbonate (93.4 g, 0.68 mol) dissolved in water (150 mL). Ethanol (260 mL) is added and then 4-bromobutyronitrile is added at 15 to 280C and the reaction mixture stirred at room temperature for 16 hours. The resulting inorganic solids are filtered off and the filtrate extracted with toluene. The organic layer is separated, dried over anhydrous Na2S04 and concentrated to give the desired 4-mercaptoacetyl butyronitrile as a yellow oil. EXAMPLE 51 Preparation of dihydrothiophenimine hydrochloride EMI108.1 Hydrogen chloride is introduced to a cooled solution of the nitrile in methanol (220 mL) for one hour and the mixture then stirred at room temperature for 16 hours. The resulting product is filtered off, washed with ether and dried to give 55.38 g of dihydrothiophenimine hydrochloride, mp 189-l950C. EXAMPLE 52 Preparation of dimethyl [(tetrahydro-2-thienylidene)- amino]fumarate (and maleate)acid EMI109.1 Dimethylacetylenedicarboxylate (0.45 mL, 0.037 mol) is added to a stirred solution of dihydrothiophenimine hydrochloride (0.5 g, 0.0036 mol) in methanol (60 mL) containing sodium acetate (0.3 g, 0.0036 mol) under an inert N2 atmosphere at -150C. After stirring for 16 hours at room temperature, the solvent is removed on a rotary evaporator and the resulting mixture separated by column chromatography on silica gel eluting with a methylene chloride-acetonitrile mixture (19:1) yielding 0.68 g (78% yield) of the desired mixed isomeric acid esters as a yellow oil. EXAMPLE 53 Preparation of dimethyl 2,3-dihydrothieno[2,3-1- pyridine-5,6-dicarboxylate EMI110.1 A Vilsmeier reagent is prepared by adding oxalyl chloride (0.25 mL, 0.0028 mol) to a stirred solution of DMF (0.22 mL, 0.0028 mol) in l,2-dichloro- ethane (50 mL) at room temperature in an inert N2 atmosphere. A 1,2-dichloroethane (50 mL) solution of dimethyl [(tetrahydro-2-thienylidine)amino]fumarate (and maleate) (0.0028 mol) is added to the Vilsmeier reagent and the reaction mixture heated at reflux for four hours. The reaction mixture is quenched with water, made basic with sodium bicarbonate and the organic layer separated and dried over anhydrous Na2S04. The solvent is removed in vacuo and the residue purified by column chromatography on silica gel, eluting with a methylene chloride-acetonitrile mixture (19:1). Crystallization from toluene-hexane affords dimethyl 2,3-dihydrothieno[2,3-bjpyridine-5,6- dicarboxylate as a white solid with mp 102-103.50C. EXAMPLE 54 Preparation of 2,3-dihydro-6-(5-isopropyl-5-methyl-4 oxo-2-imidazolin-2-yl)thieno[2,3-b]pyridine-5-carboxylic acid, l-oxide EMI111.1 m-Chloroperbenzoic acid (2.0 g, 0.0094 mol) is added to a solution of the dihydro thieno pyridine in methylene chloride (400 mL) and methanol (40 mL) at OOC under a nitrogen atmosphere. After stirring for 16 hours while attaining 180C, water 100 mL is added, followed by the addition of 100 mL of a saturated NaHC03 solution. The aqueous layer is separated off and washed with methylene chloride. Acidification with concentrated HCl, precipitates m-chlorobenzoic acid which is removed by filtration prior to adjusting the pH of the aqueous layer to pH 1. Extraction of this acidified layer with methylene chloride and removal of the solvent yields the title product as a white solid, mp 216-2180C dec. EXAMPLE 55 Preparation of diethyl dihydrothieno[3,2-b]pyridine- 5,6-dicarboxylate EMI112.1 To a solution of tetrahydrothiophene-3-one (Maybridge Chem. Co; 20.0 g, 0.196 mol) in benzene (100 mL), stirred at room temperature, is added piperidine (16.7 g, 0.196 mol) and g-toluenesulfonic acid monohydrate (0.20 g, 0.001 mol). The mixture is heated at reflux under a Dean-Stark trap for four hours, cooled and stripped to a dark brown oil consisting of a 1:1 mixture of 2,3- and 2,5-dihydrothiophene enamines (I and II; Recl. Trav. Chim., 92, 865(1973). To the above enamine mixture is added ethanol (100 mL) and diethyl ethoxymethylene oxalacetic carboxylate (72.1 g, 0.294 mol) and the mixture is stirred for 45 minutes. Ammonium acetate (45.3 g, 0.588 mol) is added in one portion and the mixture is heated at reflux for 45 minutes. After cooling, the solvents are stripped and the yellow oily diethyl dihydrothieno[3,2-b 1- pyridine-5,6-dicarboxylate product is obtained by chromatography after eluting with hexane-ethyl acetate. The mass spectrum shows the parent peak (ml/e) at 282. EXAMPLE 56 Preparation of diethyl 5,7-dihydrothieno[3,4-b]pyridine- 2,3-dicarboxylate and diethyl-2,-dihydrofuro[3,2-b] pyridine-5 , 6-dicarboxylate EMI114.1 To a solution of tetrahydrofuran-3-one (3. Pharm. Sci, 59 1678(1970); 46.55 g, 0.540 mol) in benzene (250 mL), stirred at room temperature, is added piperidine (45.98 g, 0.540 mol) and g-toluenesulfonic acid monohydrate (0.46 g, 0.002 mol). The mixture is heated at reflux under a Dean-Stark trap for four hours, cooled and stripped to a dark brown oil consisting of a 1:1 mixture of 2,3- and 2,5-dihydrothiophene enamines. Then ethanol (500 mL) and diethyl ethoxymethylene oxalacetic carboxylate (178.79 g, 1.35 mol) is added and stirring continued for 45 minutes. Ammonium acetate (124.87 g (1.62 mol) is added and the mixture is heated at reflux for 45 minutes. After cooling, the solvents are removed and the yellow oily diethyl dihydrofuro[3,2-b]pyridine-5,6-carboxylate is purified by chromatography on silica gel, eluting with hexane-ethyl acetate. The mass spectrum shows the parent peak (m+l/e) at 266. EXAMPLE 57 Preparation of 2,3-dihydro-5 and 6-(4-isopropyl-4 methyl-5-oxo-2-imidazolin-2-yl) furo and thieno-[2,3-b] and [3,2-b]pyridines Utilizing the procedures of Examples 8, 10, 12, 15, 18, 27, 35, 36, 37, 38, 49, 53, 54, 55 an 56 yields the dihydro compounds illustrated below. EMI116.1 EMI116.2 <tb> X <SEP> Y <SEP> Y' <SEP> Z <SEP> ' <SEP> R3 <SEP> mpOC <tb> S <SEP> H <SEP> H <SEP> H <SEP> H <SEP> H <SEP> 224-227 <tb> /S=0 <SEP> H <SEP> H <SEP> H <SEP> H <SEP> H <SEP> 216-218 <tb> O <SEP> H <SEP> H <SEP> H <SEP> H <SEP> H <SEP> 189-192 <tb> O <SEP> H <SEP> H <SEP> CH3 <SEP> CH3 <SEP> H <SEP> 193-198 <tb> O <SEP> H <SEP> H <SEP> HO <SEP> H <SEP> H <SEP> 170-173 <tb> O <SEP> H <SEP> H <SEP> CH30 <SEP> H <SEP> H <SEP> 140-143 <tb> EMI116.3 X Y Y' Z Z' R3 mpOC S H H H H H 239-241 O H H H H H 205-206 EXAMPLE 58 Postemergence herbicidal evaluation of test compounds The postemergence herbicidal activity of the compounds of the present invention is demonstrated by the following tests, wherein a variety of monocotyledonous and dicotyledonous plants are treated with test compounds dispersed in aqueous acetone mixtures. In the tests, seedling plants are grown in jiffy flats for about two weeks. The test compounds are dispersed in 50/50 acetone/water mixtures containing 0.5% TWEENY f a polyoxyethylene sorbitan monolaurate surfactant of Atlas Chemical Industries, in sufficient quantities to provide the equivalent of about 0.16 kg to 10 kg per hectare of active compound when applied to the plants through a spray nozzle operating at 40 psig for a predetermined time. After spraying, the plants are placed on greenhouse benches and are cared for in the usual manner, commensurate with conventional greenhouse prac tic-es. From four to five weeks after treatment, the seedling plants, are examined and rated according to the rating system provided below. The data obtained are recorded in Table I below. % Difference in Growth Rating System from the Check 0 - No Effect O 1 - Possible effect 1-10 2 - Slight effect 11-25 3 - Moderate effect 26-40 5 - Definite injury 41-60 6 - Herbicidal effect 61-75 7 - Good herbicidal effect 76-90 8 - Approaching complete kill 91-99 9 - Complete kill 100 4 - Abnormal growth, that is, a definite physiological malformation but with an over-all effect less than a 5 on the rating scale. In most cases the data are for a single test, but in several instances, they are average values obtained from more than one test. Plant Species Used Barnyardgrass (Echinochloa crusgalli) Green foxtail (Setaria viridis) Purple Nutsedge (Cyperus rotundus L.) Wild Oats (Avena fatua) Quackgrass (Agropyron repens) Field Bindweed (Convolvulus arvensis L.) Cocklebur (Xanthium pensylvanicum) Morningglory (Ipomoea purpurea) Ragweed (Ambrosia artemisiifolia) Velvetleaf (Abutilon theophrasti) Barley (Hordeum vulgare) Corn (Zea mays) Rice (Oryza sativa) Soybean (Glycine max) Sunflower (Helianthus annus) Wheat (Triticum aestivum) TABLE I POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MILD QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE S WHE Compound RATE ARDGR IL SP SEDGE OATS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N @ATD AIIDR AT ER -------- ----- ----- ----- ---- ----- ------ ----- ------ ----- ----- ----- ----- ----- ----- ----- ---- .125 6.0 8.0 8.0 9.0 8.0 9.0 6.0 2.0 3.0 5.0 4.0 8.0 7.0 0.0 3.0 5-(4-Isopropyl-4 methyl-5-oxo-2 imidazolin-2-yl) furo[3,2-b]pyridine 6-carboxylic acid 1.000 7.0 3.5 2.5 9.0 1.5 5.5 0.0 1.5 3.0 2.0 3.5 3.0 3.5 0.5 0.5 Methyl 6-(4-isopropyl-.500 2.0 2.0 0.0 7.5 1.0 5.0 0.0 1.5 0.5 0.5 1.5 2.0 3.0 0.0 0.0 .250 0.5 0.5 0.0 7.5 0.0 0.5 0.0 0.5 0.0 0.0 0.0 0.0 1.5 0.0 0.0 4-methyl-5-oxo-2- .125 0.0 0.0 0.0 4.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 1.5 0.0 0.0 imidaolin-2-yl)- .063 0.0 0.0 0.0 3.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 thieno[2,3-b]pyridine-.032 0.0 0.0 0.0 1.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 5-carboxylate 1.000 9.0 9.0 9.0 9.0 9.0 9.0 9.0 6.5 9.0 9.0 9.0 9.0 8.5 4.5 8.0 6-(4-Isopropyl-4- .500 9.0 8.0 7.5 9.0 9.0 9.0 9.0 6.5 9.0 9.0 9.0 9.0 8.5 4.5 6.0 methyl-5-oxo-2-imida- .250 8.5 8.0 7.0 9.0 9.0 9.0 8.0 4.5 9.0 8.0 9.0 9.0 6.5 3.0 4.5 zolin-2-yl)-thieno- .125 7.5 5.5 7.5 8.0 8.0 8.5 5.5 3.5 7.5 4.0 9.0 8.5 5.5 1.5 4.0 [2,3-b]pyridine-5- .063 5.0 3.0 5.5 4.5 8.0 8.0 4.5 1.5 6.0 2.0 8.5 8.0 4.0 1.5 3.0 carboxylic acid .032 4.5 1.5 3.0 3.5 4.0 7.0 3.5 0.5 4.5 1.0 7.0 6.0 3.0 1.0 1.5 1.000 9.0 7.0 8.0 9.0 8.0 9.0 3.0 4.0 9.0 9.0 9.0 9.0 8.0 2.0 2.0 2-Isopropyl-2-methyl- .500 9.0 4.0 8.0 9.0 8.0 9.0 1.0 2.0 9.0 7.0 9.0 9.0 8.0 1.0 2.0 5H-imidazo[1',2': :1,2]-.250 8.0 4.0 7.0 6.0 9.0 9.0 0.0 0.0 9.0 3.0 9.0 6.0 6.0 1.0 1.0 pyrrolo[3,4-b]thieno- .125 9.0 2.0 4.0 2.0 8.0 7.0 0.0 0.0 4.0 1.0 9.0 6.0 6.0 1.0 0.0 [3,2-e]pyridine-3(2H),-.063 7.0 1.0 2.0 1.0 8.0 0.0 0.0 1.0 1.0 9.0 3.0 4.0 0.0 0.0 5-dione .032 2.0 0.0 0.0 0.0 6.0 4.0 0.0 0.0 0.0 0.0 6.0 2.0 2.0 0.0 0.0 TABLE I (Continued) POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE S WHE Compound RATE ARDGR Il SP STDGE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD R MATD AH BR AT ER -------- ----- ----- ----- ---- ----- ------ ----- ------ ----- ----- ----- ----- ----- ----- ----- ---- 5-(4-Isopropyl-4 methyl-5-oxo-2- 1.000 9.0 8.0 8.0 9.0 9.0 9.0 6.0 7.0 9.0 9.0 9.0 7.0 9.0 3.0 4.0 imidazolin-2-yl)- .500 9.0 7.0 8.0 9.0 9.0 9.0 2.0 4.0 7.0 9.0 9.0 6.0 9.0 2.0 3.0 .250 9.0 4.0 8.0 8.0 9.0 9.0 1.0 4.0 7.0 8.0 9.0 6.0 9.0 2.0 2.0 thieno[3,2-b]pyridine- .125 8.0 2.0 6.0 8.0 8.0 3.0 0.0 2.0 4.0 4.0 9.0 5.0 8.0 1.0 1.0 6-carboxylic acid .063 6.0 2.0 4.0 4.0 7.0 3.0 0.0 0.0 0.0 2.0 9.0 2.0 6.0 1.0 0.0 .032 4.0 0.0 0.0 2.0 4.0 0.0 0.0 0.0 0.0 0.0 9.0 1.0 2.0 1.0 0.0 2-Propynyl 6-(4 isopropyl-4-methyl-5- 1.000 9.0 7.0 7.0 8.0 8.0 9.0 8.0 4.0 4.0 8.0 9.0 8.0 8.0 1.0 1.0 .500 9.0 4.0 6.0 8.0 8.0 9.0 6.0 2.0 8.0 6.0 9.0 7.0 6.0 1.0 1.0 oxo-2-imidazol in-2-yl)- .250 9.0 4.0 6.0 9.0 3.0 9.0 3.0 1.0 8.0 4.0 9.0 7.0 4.0 0.0 0.0 thieno[2,3-b]pyridine- .125 6.0 2.0 0.0 3.0 1.0 6.0 1.0 0.0 8.0 1.0 6.0 @.0 2.0 0.0 0.0 5-carboxylate .063 2.0 1.0 0.0 2.0 0.0 0.0 0.0 8.0 0.0 6.0 1.0 2.0 0.0 0.0 .032 1.0 0.0 0.0 1.0 0.0 4.0 0.0 0.0 8.0 0.0 3.0 0.0 1.0 0.0 0.0 Furfuryl- 6-(4-isopro- 1.000 9.0 9.0 9.0 9.0 9.0 9.0 9.0 4.0 9.0 8.0 9.0 8.0 9.0 2.0 2.0 pyl-4-methyl-5-oxo-2- .500 9.0 6.0 9.0 9.0 9.0 9.0 3.0 2.0 9.0 8.0 9.0 7.0 8.0 2.0 2.0 imidazolin-2-yl)- .250 8.0 4.0 7.0 8.0 9.0 9.0 1.0 1.0 9.0 6.0 9.0 7.0 6.0 1.0 1.0 .175 6.0 2.0 4.0 7.0 8.0 7.0 0.0 0.0 8.0 3.0 8.0 6.0 4.0 0.0 thleno[2,3-b]pyridine- .063 4.0 1.0 2.0 4.0 4.0 7.0 0.0 0.0 4.0 0.0 3.0 3.0 4.0 0.0 0.0 5-carboxylate .032 2.0 0.0 0.0 2.0 1.0 4.0 0.0 0.0 2.0 0.0 2.0 2.0 2.0 0.0 0.0 2-Melhylallyl 6-(4-isn- 1.000 9.0 7.0 8.0 8.0 8.0 9.0 8.0 0.0 9.0 @.0 8.0 7.0 7.0 0.0 0.0 propyl-4-methyl-5-oxo- .500 7.0 6.0 6.0 7.0 8.0 7.0 2.0 0.0 9.0 1.0 8.0 7.0 8.0 0.0 0.0 .@30 7.0 4.0 2.0 8.0 4.0 8.0 0.0 0.0 @.0 1.0 6.0 7.0 4.0 0.0 0.0 2-Imidaolin-2-yl)- .12@ 4.0 2.0 0.0 3.0 1.0 6.0 0.0 0.0 4.0 1.0 4.0 7.0 4.0 0.0 0.0 thieno[2,3-b]pyridine- .063 2.0 0.0 0.0 2.0 1.0 4.0 0.0 0.0 2.0 0.0 3.0 6.0 3.0 0.0 0.0 5-carboxylate .032 0.0 0.0 0.0 2.0 0.0 2.0 0.0 0.0 0.0 0.0 2.0 4.0 2.0 0.0 0.0 TABLE I (Continued) POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE S WHE Compound RATE ARDGR IL SP SEGE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N NATD AH BR AT ER -------- ----- ----- ----- ---- ----- ------ ----- ------ ----- ----- ----- ----- ----- ----- ----- ---- 3-Chloro-5-(4-iso propyl-4-methyl-5- 1.000 3.0 6.0 0.0 7.0 0.0 6.0 0.0 6.0 6.0 0.0 7.0 4.0 7.0 0.0 0.0 oxo-2-imidazolin-2- .500 2.0 2.0 0.0 6.0 0.0 2.0 0.0 2.0 0.0 7.0 4.0 0.0 0.0 .250 1.0 0.0 0.0 2.0 0.0 2.0 0.0 1.0 3.0 0.0 6.0 2.0 2.0 0.0 0.0 yl)-thieno[3,2-b]- .125 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 3.0 1.0 1.0 0.0 0.0 pyridine-6-carbo- .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 1.0 0.0 0.0 xylic acid .032 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 1.0 0.0 0.0 3-Bromo-5-(4-iso- 1.000 0.0 2.0 2.0 0.0 2.0 2.0 2.0 6.0 2.0 0.0 6.0 2.0 0.0 2.0 propyl-4-methyl-5- .500 0.0 1.0 0.0 0.0 0.0 1.0 1.0 6.0 2.0 0.0 6.0 1.0 0.0 2.0 oxo-2-imidazolin-2- .250 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.0 0.0 4.0 0.0 0.0 2.0 yl)-thieno[3,2-b]- .125 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 1.0 .063 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 pyridine-6-carbo- .032 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 xylic acid 3-Bromo-6-(4-iso- 1.000 9.0 7.0 2.0 9.0 7.0 7.0 9.0 6.0 8.0 3.0 9.0 9.0 6.0 2.0 6.0 propyl-4-methyl-5- .500 8.0 7.0 1.0 8.0 7.0 4.0 8.0 2.0 8.0 1.0 9.0 9.0 6.0 0.0 5.0 oxo-2-imidazolin-2- .250 4.0 5.0 0.0 8.0 4.0 4.0 2.0 0.0 8.0 0.0 9.0 9.0 3.0 0.0 5.0 yl)-thieno[2,3-b] .125 2.0 3.0 0.0 7.0 4.0 4.0 9.0 0.0 8.0 0.0 8.0 9.0 2.0 0.0 2.0 .063 0.0 0.0 0.0 3.0 0.0 0.0 9.0 0.0 6.0 0.0 7.0 9.0 2.0 0.0 2.0 pyridine-5-carbo- .032 0.0 0.0 0.0 0.0 0.0 0.0 9.0 0.0 4.0 0.0 3.0 9.0 2.0 0.0 2.0 xylic acid 1.000 9.0 9.0 5.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 7.0 5.0 8.0 6-(4-Isopropyl-4 .500 9.0 9.0 5.0 9.0 9.0 9.0 9.0 9.0 6.0 8.0 9.0 9.0 8.0 5.0 8.0 methyl-5-oxo-2-imida- .250 9.0 9.0 5.0 8.0 5.0 8.0 8.0 8.0 3.0 8.0 9.0 9.0 8.0 4.0 7.0 zolin-2-yl)-2-methyl- .125 8.0 8.0 2.0 5.0 7.0 2.0 4.0 0.0 0.0 6.0 9.0 9.0 7.0 2.0 7.0 .063 3.0 3.0 1.0 5.0 3.0 4.0 0.0 7.0 0.0 2.0 9.0 9.0 6.0 2.0 3.0 thieno[2,3-b]pyridine .032 0.0 0.0 0.0 2.0 2.0 9.0 0.0 4.0 0.0 0.0 9.0 9.0 6.0 2.0 2.0 5-carboxylic acid TABLE I (Continued) POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE S WHE Compound RATE ARDGR IL SP SEDCE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N NATD AN BR AT ER --------- ----- ----- ----- ----- ----- ------ ----- ------ ----- ------ ------ ----- ----- ----- ----- ---- Furfuryl 5-(4-iso 1.000 9.0 9.0 8.0 8.0 8.0 9.0 8.0 8.0 8.0 7.0 9.0 9.0 6.0 3.0 2.0 propyl-4-methyl-5- .500 9.0 7.0 8.0 9.0 8.0 9.0 5.0 8.0 0.0 5.0 9.0 9.0 6.0 2.0 1.0 oxo-2-imidazolin- .250 9.0 7.0 7.0 8.0 7.0 9.0 2.0 7.0 8.0 5.0 9.0 8.0 5.0 3.0 1.0 2-yl)-thieno[3,2-b]- .125 9.0 4.0 6.0 6.0 8.0 7.0 0.0 7.0 7.0 2.0 9.0 5.0 2.0 0.0 .063 7.0 0.0 2.0 4.0 4.0 4.0 0.0 4.0 2.0 0.0 7.0 2.0 4.0 2.0 0.0 pyridine-6-carbo- .032 0.0 0.0 2.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 2.0 3.0 2.0 0.0 xylate 3-Chloro-6-(4-iso- 1.000 9.0 9.0 8.0 9.0 9.0 9.0 9.0 2.0 9.0 4.0 9.0 9.0 6.0 1.0 9.0 propyl-4-methyl-5- .500 9.0 8.0 6.0 9.0 9.0 8.0 9.0 0.0 9.0 3.0 9.0 9.0 6.0 0.0 8.0 oxo-2-imidazolin- .250 8.0 7.0 2.0 9.0 8.0 9.0 8.0 0.0 9.0 0.0 9.0 9.0 6.0 2.0 6.0 2-yl)-thieno[2,3-b]- .125 6.0 6.0 0.0 9.0 6.0 6.0 2.0 0.0 8.0 0.0 9.0 9.0 5.0 1.0 6.0 .063 4.0 0.0 0.0 8.0 3.0 6.0 0.0 0.0 0.0 9.0 9.0 5.0 0.0 4.0 pyridine-5-carbo- .032 0.0 0.0 0.0 4.0 0.0 0.0 0.0 0.0 0.0 8.0 2.0 4.0 0.0 2.0 xyllc acid 6-(4-Isopropyl-4- 1.000 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 6.0 9.0 methyl-5-oxo-2-imida- .500 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 8.0 6.0 9.0 zollin-2-yl)furo- .250 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 8.0 6.0 8.0 .125 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 8.0 3.0 9.0 [2,3-b]pyridine-5- .061 9.0 9.0 8.0 9.0 8.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 7.0 2.0 8.0 caroxylic acid .032 9.0 9.0 7.0 9.0 8.0 9.0 4.0 8.0 9.0 7.0 9.0 9.0 7.0 2.0 7.0 2,3-Dlhydro-6-(4- 1.000 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 8.0 7.0 9.0 isopropyl-4-methyl- .500 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 8.0 6.0 9.0 5-oxo-2-imidazolin- .250 9.0 9.0 9.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 9.0 9.0 8.0 6.0 9.0 .125 9.0 9.0 9.0 9.0 9.0 9.0 6.0 9.0 9.0 9.0 9.0 9.0 0.0 3.0 9.0 2-yl)-furo[2,3-b]- .063 9.0 8.0 9.0 8.0 8.0 8.0 2.0 7.0 8.0 6.0 6.0 9.0 8.0 1.0 1.0 pyridine-5-carbo- .032 9.0 6.0 8.0 8.0 7.0 8.0 0.0 4.0 7.0 2.0 6.0 9.0 7.0 1.0 2.0 xylic acid EXAMPLE 59 Preemergence herbicidal evaluation of test compounds The preemergence herbicidal activity of the compounds of the present invention is exemplified by the following tests in which the seeds of a variety of monocotyledonous and dicotyledonous plants are separately mixed with potting soil and planted on top of approximately one inch of soil in separate pint cups. After planting, the cups are sprayed with the selected aqueous acetone solution containing test compound in sufficient quantity to provide the equivalent of about 0.016 to 10 kg per hectare of test compound per cup. The treated cups are then placed on greenhouse benches, watered and cared for in accordance with conventional greenhouse procedures. From four to five weeks after treatment, the tests are terminated and each cup is examined and rated according to the rating system set forth above. The herbicidal proficiency of the active ingredients of the present invention is evident from the test :results which are recorded in Table II below. Where more than one test is involved for a given compound, the data are averaged. TABLE II POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE S WHE Compound RATE ARDGR IL SP SEDCE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N NATD AN BR AT ER --------- ----- ----- ----- ----- ----- ------ ----- ------ ----- ------ ------ ----- ----- ----- ----- ---- lethyl 6-(4-iso @ropyl-4-methyl- .500 8.5 8.5 7.5 8.5 8.0 9.0 6.5 9.0 9.0 7.5 5.0 5.0 7.5 6.5 1.5 1.5 @-oxo-2-imidazo- .250 7.0 5.5 7.0 8.0 1.0 9.0 4.5 6.0 6.5 6.0 2.0 3.5 7.0 5.5 1.0 0.5 in-2-yl)-thieno- .0125 5.0 3.0 4.0 7.0 1.5 7.0 2.5 5.5 5.5 4.5 0.0 3.0 5.5 4.5 0.5 0.5 2,3-b]pyridine-5- .063 1.5 1.0 2.5 5.0 0.5 2.0 0.5 5.0 1.0 2.0 0.0 1.5 2.5 2.0 0.0 0.0 .032 0.5 8.5 1.0 2.0 0.0 1.0 0.0 2.0 0.0 2.0 0.0 1.5 1.5 2.0 0.0 0.0 carboxylate .016 0.0 0.0 0.5 1.0 0.0 0.0 0.0 1.0 1.0 1.0 0.0 1.0 1.5 0.5 0.0 0.0 @-(4-Isoprpyl-4- .500 9.0 9.0 9.0 9.0 9.0 9.0 8.5 5.5 8.5 9.0 9.0 9.0 9.0 9.0 5.0 5.5 nethyl-5-oxol-2- .250 6.5 8.5 9.0 9.0 9.0 9.0 8.0 4.5 8.0 7.0 8.0 8.0 9.0 8.0 3.0 5.0 .125 5.5 8.0 9.0 7.5 9.0 9.0 8.0 4.5 8.5 7.0 8.0 9.0 9.0 8.0 2.5 4.0 imidazolin-2-yl)- .0@3 3.0 4.0 8.5 7.5 8.0 9.0 7.0 3.5 6.0 4.5 6.0 6.0 7.5 6.0 0.5 2.0 @hieno[2,3-b]pyri- .032 1.5 2.5 8.0 5.0 7.5 7.0 5.5 4.0 2.0 2.5 5.0 3.0 5.0 5.5 0.5 1.5 line-5-carboxylic .016 0.0 0.0 6.0 2.0 6.5 5.0 3.5 1.0 0.0 1.0 3.0 2.0 3.0 2.5 0.0 0.5 lcid @-Isopropyl-2-methyl- .500 9.0 9.0 9.0 9.0 9.0 9.0 9.0 6.0 9.0 8.0 9.0 9.0 9.0 9.0 4.0 7.0 .250 9.0 8.0 9.0 9.0 9.0 9.0 7.0 4.0 9.0 7.0 8.0 9.0 8.0 7.0 3.0 2.0 @H-imidazo[1',2': :1,2]- .125 9.0 7.0 9.0 8.0 9.0 9.0 9.0 4.0 7.0 5.0 8.0 9.0 8.0 6.0 1.0 2.0 @yrrolo[3,4-b]thieno- .063 3.0 2.0 8.0 7.0 9.0 9.0 6.0 1.0 7.0 3.0 7.0 6.0 6.0 4.0 1.0 2.0 3,2-e]pyridine-3(2H), .032 0.0 0.0 8.0 3.0 4.0 9.0 3.0 0.0 0.0 2.0 5.0 4.0 4.0 2.0 1.0 1.0 @-dione .016 0.0 0.0 6.0 1.0 0.0 7.0 1.0 0.0 0.0 0.0 1.0 2.0 2.0 1.0 1.0 0.0 @-(4-isopropyl-4- .500 9.0 8.0 9.0 9.0 8.0 9.0 9.0 7.0 9.0 8.0 9.0 9.0 9.0 9.0 4.0 9.0 @ethyl-5-oxo-2- .250 9.0 9.0 9.0 9.0 8.0 9.0 8.0 6.0 6.0 7.0 9.0 9.0 9.0 9.0 2.0 3.0 .125 9.0 7.0 9.0 8.0 7.0 9.0 8.0 5.0 8.0 5.0 8.0 9.0 9.0 9.0 1.0 3.0 @mldazolin-2-yl)- .063 2.0 4.0 8.0 3.0 3.0 9.0 6.0 3.0 7.0 3.0 6.0 5.0 7.0 8.0 0.0 1.0 @hieno[3,2-b]pyridine- .032 0.0 2.0 6.0 1.0 1.0 9.0 5.0 1.0 4.0 3.0 2.0 3.0 7.0 5.0 0.0 0.0 @-carboxylic acid .016 0.0 0.0 4.0 0.0 0.0 8.0 4.0 0.0 0.0 2.0 0.0 2.0 5.0 2.0 0.0 0.0 TABLE II (Continued) POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE S WHE Compound RATE ARDGR IL SP SEDCE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N NATD AN BR AT ER --------- ----- ----- ----- ----- ----- ------ ----- ------ ----- ------ ------ ----- ----- ----- ----- ---- 2-Propynyl 6-(4 isopropyl-4-methyl- .500 9.0 9.0 9.0 9.0 9.0 9.0 9.0 6.0 9.0 9.0 8.0 9.0 9.0 9.0 1.0 5.0 5-oxo-2-imdazolin- .250 9.0 9.0 9.0 8.0 9.0 9.0 8.0 2.0 9.0 9.0 8.0 3.0 9.0 7.0 0.0 3.0 .125 9.0 6.0 9.0 6.0 9.0 9.0 8.0 1.0 8.0 7.0 4.0 3.0 7.0 7.0 0.0 2.0 2-yl)-thieno[2,3-b]- .063 7.0 5.0 6.0 6.0 8.0 9.0 7.0 0.0 7.0 3.0 3.0 3.0 6.0 5.0 0.0 2.0 pyridine-5-carbo- .032 0.0 0.0 7.0 3.0 7.0 9.0 0.0 0.0 5.0 1.0 0.0 3.0 6.0 4.0 0.0 2.0 xylate .016 0.0 0.0 6.0 2.0 5.0 9.0 0.0 0.0 0.0 0.0 0.0 2.0 3.0 2.0 0.0 2.0 Furfuryl 6-(4- .500 9.0 9.0 9.0 9.0 9.0 9.0 9.0 3.0 9.0 8.0 9.0 9.0 9.0 9.0 3.0 4.0 isopropyl-4-methyl- .250 9.0 8.0 9.0 9.0 9.0 9.0 8.0 1.0 9.0 6.0 8.0 9.0 9.0 @.0 1.0 2.0 5-oxo-2-imidazolin- .125 8.0 8.0 9.0 9.0 8.0 9.0 0.0 0.0 7.0 6.0 2.0 9.0 8.0 7.0 1.0 2.0 2-yl)-thieno[2,3-b]- .063 2.0 3.0 6.0 3.0 5.0 8.0 6.0 0.0 2.0 3.0 0.0 2.0 8.0 5.0 0.0 1.0 .032 0.0 0.0 2.0 3.0 8.0 5.0 0.0 2.0 0.0 2.0 6.0 3.0 0.0 1.0 pyridine-5-carboxylate .016 0.0 0.0 2.0 1.0 0.0 3.0 4.0 0.0 0.0 0.0 0.0 2.0 0.0 1.0 0.0 0.0 2-Methylallyl 6-(4- .500 9.0 9.0 6.0 8.0 9.0 9.0 9.0 0.0 9.0 8.0 5.0 4.0 7.0 7.0 0.0 1.0 isopropyl-4-methyl-5- .250 2.0 3.0 6.0 0.0 6.0 7.0 4.0 0.0 3.0 6.0 0.0 2.0 7.0 3.0 0.0 0.0 oxo-2-imidazolin-2-yl)- .125 0.0 0.0 3.0 0.0 4.0 4.0 4.0 0.0 0.0 2.0 0.0 2.0 0.0 1.0 0.0 0.0 .063 0.0 0.0 1.0 0.0 3.0 3.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 thieno[2,3-b]pyrldine- .032 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 5-carboxylate .016 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3-Chloro-5-(4-isopropyl- .500 2.0 4.0 7.0 8.0 7.0 9.0 7.0 8.0 8.0 8.0 8.0 8.0 9.0 3.0 3.0 4-methyl-5-oxo-2- .250 2.0 4.0 7.0 6.0 7.0 9.0 3.0 8.0 8.0 7.0 7.0 8.0 9.0 3.0 3.0 imidazolin-2-yl)-thleno- .125 1.0 0.0 2.0 2.0 6.0 2.0 0.0 7.0 6.0 2.0 7.0 6.0 2.0 1.0 1.0 [3,2-b]pyridine-6- .063 1.0 0.0 2.0 2.0 2.0 1.0 0.0 2.0 2.0 0.0 4.0 4.0 2.0 0.0 0.0 .032 0.0 0.0 2.0 1.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 1.0 0.0 0.0 carboxylic acid .016 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 TABLE II (Continued) POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE SOYBE Compound RATE ARDGR IL SP SEDCE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N NATO AN BR AN WI --------- ----- ----- ----- ----- ----- ------ ----- ------ ----- ------ ------ ----- ----- ----- ----- ---- 3-Bromo-5-(4-isopro pyl-4-methyl-5-oxo- .500 6.0 6.0 5.0 6.0 0.0 4.0 2.0 8.0 8.0 4.0 9.0 4.0 4.0 2.0 0.0 2-imidazolin-2-yl)- .250 5.0 5.0 4.0 2.0 2.0 7.0 8.0 4.0 5.0 4.0 4.0 2.0 0.0 thieno[3,2-b]pyri- .125 4.0 2.0 2.0 1.0 1.0 6.0 6.0 2.0 6.0 3.0 3.0 2.0 0.0 .063 2.0 0.0 1.0 0.0 0.0 0.0 0.0 5.0 0.0 0.0 0.0 2.0 2.0 0.0 0.0 dine-6-carboxylic .032 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 2.0 0.0 0.0 acid .016 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 2.0 0.0 0.0 3-Bromo-6-(4-isopro pyl-4-methyl-5-oxo- .500 9.0 9.0 8.0 9.0 9.0 9.0 9.0 7.0 9.0 9.0 9.0 9.0 9.0 2.0 9.0 2-imidazolin-2-yl)- .250 9.0 9.0 7.0 9.0 7.0 9.0 9.0 9.0 8.0 9.0 9.0 9.0 3.0 6.0 .125 8.0 7.0 7.0 9.0 8.0 9.0 8.0 8.0 7.0 9.0 9.0 6.0 8.0 thieno[2,3-b]pyridine- .063 7.0 2.0 4.0 8.0 0.0 9.0 6.0 2.0 8.0 3.0 8.0 7.0 6.0 2.0 8.0 5-carboxylic acid .032 7.0 2.0 0.0 8.0 0.0 9.0 2.0 8.0 4.0 7.0 4.0 2.0 6.0 .016 2.0 0.0 0.0 6.0 0.0 9.0 0.0 2.0 4.0 0.0 6.0 3.0 2.0 4.0 6-(4-isopropyl-4 .500 9.0 9.0 8.0 9.0 9.0 9.0 8.0 9.0 8.0 9.0 9.0 9.0 8.0 4.0 9.0 methyl-5-oxo-2-imida- .250 9.0 9.0 8.0 9.0 9.0 9.0 8.0 9.0 8.0 9.0 9.0 9.0 9.0 6.0 zolin-2-yl)-2-methyl- .125 8.0 6.0 8.0 7.0 9.0 9.0 8.0 9.0 8.0 9.0 9.0 9.0 8.0 7.0 thieno[2,3-b]pyridine- .063 6.0 4.0 3.0 9.0 4.0 8.0 9.0 8.0 8.0 8.0 9.0 6.0 4.0 6.0 .032 3.0 2.0 4.0 2.0 9.0 4.0 3.0 6.0 2.0 4.0 7.0 7.0 4.0 2.0 3.0 5-carboxylic acid .016 4.0 6.0 3.0 2.0 6.0 2.0 2.0 2.0 4.0 5.0 3.0 2.0 3.0 Furfuryl 5-(4-isopro .500 9.0 9.0 8.0 9.0 9.0 9.0 8.0 8.0 9.0 9.0 9.0 9.0 9.0 2.0 7.0 pyl-4-methyl-5-oxo-2- .250 9.0 9.0 8.0 9.0 9.0 7.0 8.0 9.0 9.0 9.0 9.0 9.0 9.0 2.0 7.0 imidazolin-2-yl)-thieno- .125 8.0 9.0 9.0 9.0 7.0 7.0 7.0 9.0 7.0 7.0 9.0 9.0 2.0 3.0 [3,2-b]pyridine-6- .063 8.0 6.0 8.0 8.0 6.0 2.0 7.0 8.0 7.0 7.0 9.0 8.0 2.0 .032 7.0 6.0 8.0 6.0 7.0 2.0 6.0 8.0 6.0 4.0 9.0 8.0 2.0 carboxylate .016 5.0 5.0 2.0 2.0 0.0 2.0 2.0 4.0 2.0 9.0 6.0 2.0 2.0 TABLE II (Continued) POST-EMERGENCE TESTS -- RATES IN KG/HA BARNY FDKTA F NUT MIID QUACK FLU B MATRI MRLIGL RAGNE VELVE N BAR CORN COTTO RICE, SDYBE SOYBE Compound RATE ARDGR IL SP SEDCE OAIS GRASS IMDIID CARIA RY SP ED TLEAF LY MA FIELD N NATO AN BR AN WI --------- ----- ----- ----- ----- ----- ------ ----- ------ ----- ------ ------ ----- ----- ----- ----- ---- 3-Chloro-6-(4-iso propyl-4-methyl-5- .500 9.0 9.0 8.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 4.0 @.0 imidazolin-2-yl)- .250 9.0 9.0 6.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 3.0 8.0 .125 8.0 7.0 5.0 9.0 7.0 9.0 8.0 9.0 9.0 7.0 9.0 9.0 9.0 2.0 7.0 thien[2,3-b]- .063 7.0 7.0 4.0 9.0 4.0 7.0 8.0 6.0 8.0 3.0 8.0 9.0 9.0 7.0 pyridine-5-carbo- .032 6.0 7.0 3.0 9.0 3.0 6.0 6.0 0.0 8.0 3.0 8.0 9.0 6.0 2.0 6.0 xylic acid .016 5.0 2.0 0.9 9.0 2.0 3.0 4.0 8.0 2.0 5.0 9.0 7.0 8.0 2.0 6-(4-isopropyl-4- .250 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 7.0 9.0 methyl-5-oxo-2- .125 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 6.0 9.0 imidazolin-2-yl)- .063 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 7.0 9.0 .032 9.0 9.0 9.0 9.0 9.0 9.0 9.0 8.0 8.0 9.0 9.0 9.0 9.0 7.0 8.0 furo[2,3-b]pyri- .016 7.0 9.0 9.0 8.0 7.0 9.0 7.0 8.0 8.0 9.0 9.0 9.0 6.0 7.0 dine-5-carboxylic 5.0 acid 2,3-dihydro-6-(4- .500 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 7.0 9.0 isopropyl-4-methyl- .250 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 9.0 5.0 8.0 .125 9.0 9.0 9.0 9.0 9.0 9.0 6.0 8.0 7.0 8.0 8.0 9.0 9.0 4.0 8.0 5-oxo-2-imidazo- .063 9.0 9.0 9.0 8.0 7.0 9.0 0.0 8.0 8.0 9.0 9.0 3.0 7.0 lin-2-yl)-furo- .032 9.0 6.0 9.0 9.0 8.0 9.0 0.0 5.0 0.0 8.0 8.0 9.0 8.0 6.0 [2,3-b]pyridine-5- .016 9.0 4.0 9.0 7.0 5.0 7.0 0.0 5.0 0.0 6.0 5.0 9.0 6.0 6.0 carboxylic acid EXAMPLE 60 Plant growth regulant evaluation of the compounds The plant growth regulant activity of the compounds of the present invention is demonstrated by the following test, wherein barley (Hordeum vulgare) is treated with a test compound dissolved in aqueous acetone. In the test, the compound dissolved acetone/ water mixtures 50/50 containing 0.25% by volume of Colloidal Multi-film X-77 surfactant (alkylarylpolyoxy ethyleneglycols, free fatty acids and isopropanol) of Colloidal Products Corporation (Petaluma, California) in sufficient quantities to provide the equivalent of about 0.00625 kg to 0.10 kg per hectare of active compound when applied to the plants when the first node is detectable (Zadok 30). After spraying, the plants are placed on greenhouse benches and are cared for in the usual manner, commensurate with conventional greenhouse practices. From 11 to 12 weeks after treatment the plants are measured and harvested. The heads are removed and dried for 48 hours at 85 to 900C and weights recorded. The data obtained are recorded in Table III below. TABLE III Plant growth regulant activity test Total Rate Head Increase Compound kg/ha Replicate Dry wt/g Head wt Untreated control - 1 56.7 2 2 55.9 3 3 60.6 Average 57.7 Furfuryl 6-(4-iso- 0.10 1 64.5 propyl-4-methyl-5- 2 68.2 oxo-2-imidazolin- 3 66.1 2-yl)-thieno[2,3-b]- Average 66.3 14. 9 pyridine-5-carboxylate 0.05 1 66.6 2 74.1 3 77.7 Average 72.8 26.1 0.025 1 52.9 2 70.6 3 68.7 Average 64.0 10.9 0.0125 1 64.9 2 72.6 3 75.5 Average 71.0 23.0 0.00625 1 58.6 2 67.5 3 68.4 Average 64 . 9 12.5

Claims: WHAT IS CLAIMED IS: 1. A compound having the structure: EMI130.1 EMI131.1 wherein - - represents a single or a double bond; Rl is Cl-C4 alkyl; R2 is C1-C4 alkyl or C3-C6 cycloalkyl; and when R1 and R2 are taken together with the carbon to which they are attached they may represent C3-Có cycloalkyl optionally substituted with methyl; A is COOR3, CHO, CH20H, COCH20H, CONBCH2CH20H, CONHOH, or EMI132.1 R3 is hydrcgen, Cl-C12 alkyl, which may b interrupted by one or more 0 or S and is optionally substituted with one of the following groups: C1-C3 alkoxy, halogen, hydroxy, C3-C6 cycloalkyl, benzyloxy, furyl, phenyl, furfuryl, halophenyl, loweralkylphenyl, loweralkoxyphenyl, nitrophenyl, carboxyl, loweralkoxycarbonyl, cyano, C1-C4 alkylthio or triloweralkylammonium, C3-C6 alkenyl optionally substituted with one of the following groups: C1-C3 alkoxy, phenyl, halogen or with two Cf-C3 alkoxy groups or two halogen groups: C3-C6 cycloalkyl optionally substituted with one or two C1-C3 alkyl groups; C3-ClO alkynyl optionally substituted with phenyl, halogen or CH20H; or a cation of alkali metals, alkaline earth metals, (Ca, Ba) manganese, copper, iron, ammonium or organic ammonium; RC and RD are H or CH3; B is H, COR4 or S02R5, provided that when B is COR4 or SQ2R5, and A is COOR3, R3 cannot be hydrogen or a salt-forming cation; R4 is C1-C11 alkyl, chloromethyl or phenyl optionally substituted with one chloro, one nitro, one methyl, or one methoxy group; R5 is C1-C5 alkyl or phenyl optionally substituted with one methyl group, chloro or nitro; W is O or S; X is 0, S, or, where - - is a single bond, -=0; Y and Y', Z and Z' are hydrogen, halogen, C1-C6 alkyl, C1-C4 hydroxyloweralkyl, C1-C6 alkoxy, C1-C6 acyloxy, benzoyloxy optionally substituted with one or two C1-C4 alkyl, C1-C4 alkoxy, halogen; Cl- C4 alkylthio, phenoxy, C1-C4 baloalkyl, C1-C4 haloalkoxy, nitro, cyano, C1-C4 alkylamino, C1-C4 dialkylamino, C1-C4 alkylsulfonyl or phenyl optionally substituted with one or two C1-C4 alkyl, C1-C4 alkoxy, halogen, or any combination of two of these groups and wherein Y and Z are the same group provided that Y and Z are H, halogen, alkyl or alkoxy, and when Y and Y' or Z and Z' are the same group they are hydrogen or alkyl; and, when taken together, Y and Z may form a ring in which YZ are represented by the structure -(CH2)n-, where n is an integer selected from 3 or 4; or EMI133.1 where L, M, Q and R7 each represent hydrogen, halogen, nitro, C1-C4 loweralkyl, C1-C4 loweralkoxy, methoxy, phenyl and phenoxy, with the proviso that only one of L, M, Q or R7, may represent a substituent other than hydrogen, halogen, C1-C4 alkyl or C1-C4 alkoxy; or the pyridine N-oxides thereof, when W is O or S and A is COOR3; and when R1 and R2 are not the same, the optical isomers thereof, and, except when R3 is a salt-forming cation, the acid addition salts thereof. 2. A compound according to Claim I having the structure: EMI134.1 wherein Y is hydrogen, or methyl; Z is hydrogen, chlorine or bromine, R3 is hydrogen, propynyl, furfuryl, or a sodium, ammonium or organic ammonium cation; W is O or S. 3. A compound according to Claim 1 having the structure: EMI134.2 wherein Y is hydrogen or methyl; Z is hydrogen, chlorine or bromine; R3 is hydrogen, furfuryl, or a sodium ammonium or organic ammonium cation; W is O or S. 4. The compound according to Claim 2, furfuryl 6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl) thieno-[2,3-b]pyridine-5-carboxylate. 5. A compound according to Claim 2, 6-(4-iso propyl-4-methyl-5 oxo-2-imidazolin-2-yI)-thieno- [2,3-b]pyridine-5-carboxylic acid. 6. The compound according to Claim 2, propynyl-6-(4-isopropyl-4-methyl-5-oxo-2-imidazolin 2-yl)-thieno[2,3-b]pyridine-5-carboxylate. 7. The compound according to Claim 3. 6 (4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)furo j2,3-b]pyridine-5-carboxylic acid. 8. A method for the control of monocotyle donous and dicotyledonous annual, perennial and aquatic plant species comprising: applying to the foliage of said plants or to soil or water containing seeds or other propogating organs thereof, a herbicidally effective amount of a compound having a structure: EMI136.1 wherein -- represents a single or a double bond; R1 is C1-C4 alkyl; R2 is C1-C4 alkyl or C3-C6 cycloalkyl; and when Rl and R2 are taken together with the carbon to which they are attached they may represent C3-C6 cycloalkyl optionally substituted with methyl; A is COOR3, CHO, CH20H, COCH20H, CONHCH2CH20H, CONHOH, or EMI137.1 R3 is hydrogen, Cl-C12 alkyl optionally substituted with one of the following groups: C1-C3 alkoxy, halogen, hydroxy, C3-C6 cycloalkyl, benzyloxy, furyl, phenyl, furfuryl, halophenyl, loweralkylphenyl, loweralkoxyphenyl, nitrophenyl, carboxyl, loweralkoxycarbonyl, cyano, C1-C4 alkylthio or triloweralkylammonium, in addition the alkyl chain may be interrupted by one or more 0 or S; C3-C6 alkenyl optionally substituted with one of the following groups: C1-C3 alkoxy, phenyl, halogen or with two C1-C3 alkoxy groups or two halogen groups: C3-C6 cycloalkyl optionally substituted with one or two C1-C3 alkyl groups; C3-C10 alkynyl optionally substituted with phenyl, halogen or CH20H; or a cation of alkali metals, alkaline earth metals, (Ca, Ba) manganese, copper, iron, ammonium or organic ammonium; RC and RD are H, or CH3; B is H, COR4 or S02R5, provided that when B is COR4 or S02R5, and A is COOR3, R3 cannot be hydrogen or a salt-forming cation; R4 is Cl-Cll alkyl, chloromethyl or phenyl optionally substituted with one chloro, one nitro, one methyl, or one methoxy group; R5 is C1-C5 alkyl or phenyl optionally substituted with one methyl group, chloro or nitro; W is O or S; X is O, S, or -=O; Y and Y', Z and Z' are hydrogen, halogen, C1-C6 alkyl, C1-C4 hydroxyloweralkyl, C1-C6 alkoxy, Cl-C6 acyloxy, benzoyloxy optionally substituted with one or two Cl-C4 alkyl, C1-C4 alkoxy, halogen; Cl- C4 alkylthio, phenoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, nitro, cyano, Cl-C4 alkylamino, C1-C4 dialkylamino, Cl-C4 alkylsulfonyl or phenyl optionally substituted with one or two Cl-C4 alkyl, Cl-C4 alkoxy, halogen, or any combination of two of these groups and wherein Y and Z are the same group provided that Y and Z are H, halogen, alkyl or alkoxy, and when Y and Y' or Z and Z' are the same group they are hydrogen or alkyl; and, when taken together, Y and Z may form a ring in which YZ are represented by the structure -(CH2)n-, where n is an integer selected from 3 or 4; or EMI138.1 where L, M, Q and R7 each represent hydrogen, halogen, nitro, C1-C4 loweralkyl, C1-C4 loweralkoxy, methoxy, phenyl and phenoxy, with the proviso that only one of L, M, Q or R7, may represent a substituent other than hydrogen, halogen, Cl-C4 alkyl or C1-C4 alkoxy; or the pyridine N-oxides thereof, when W is O or S and A is COOR3; and when R1 and R2 are not the same, the optical isomers thereof, and, except when R3 is a saltforming cation, the acid addition salts thereof. 9. A method for regulating the growth of plants and increasing the yield of gramineacous and liguminous crops, comprising applying to the foliage of said plants an effective amount of a compound selected from the compounds having the structures: EMI139.1 wherein -- represents a single or a double bond; R3 is hydrogen, C1-C12 alkyl optionally substituted with one of the following groups: C1-C3 alkoxy, halogen, hydroxy, C3-C6 cycloalkyl, benzyloxy, furyl, phenyl, furfuryl, halophenyl, loweralkylphenyl, loweralkoxyphenyl, nitrophenyl, carboxyl, loweralkoxycarbonyl, cyano, C1-C4 alkylthio or trilowelalkylammonium, in addition the alkyl chain may be interrupted by one or more 0 or S; C3-C6 alkenyl optionally substituted with one of the following groups: C1-C3 alkoxy, phenyl, halogen or with two C1-C3 alkoxy groups or two halogen groups: C3-C6 cycloalkyl optionally substituted with one or two C1-C3 alkyl groups; C3-C10 alkynyl optionally substituted with phenyl, halogen or CH20H; or a cation of alkali metals, alkaline earth metals, (Ca, Ba) maganese, copper, iron, ammonium or organic ammonium; X is 0, S, or -5;=Q; Y and Y', Z and Z' are hydrogen, halogen, C1-C6 alkyl, C1-C4 hydroxyloweralkyl, C1-C6 alkoxy, C1-C6 acyloxy, benzoyloxy optionally substituted with one or two Cl-C4 alkyl, C1-C4 alkoxy, halogen; ; Cl- C4 alkylthio, phenoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, nitro, cyano, C1-C4 alkylamino, C1-C4 dialkylamino, C1-C4 alkylsulfonyl or phenyl optionally substituted with one or two C1-C4 alkyl, C1-C4 alkoxy, halogen, or any combination of two of these groups and wherein Y and Z are the same group provided that Y and Z are H, halogen7 alkyl or alkoxy, and when Y and Y' or Z and Z' are the same group they are hydrogen or alkyl; and, when taken together, Y and Z may form a ring in which YZ are represented by the structure -(CH2)n-, where n is an integer selected from 3 or 4; or EMI140.1 where L, M, Q and R7 each represent hydrogen, halogen, nitro, C1-C4 loweralkyl, C1-C4 loweralkoxy, methoxy, phenyl and phenoxy, with the proviso that only one of L, M, Q or R7, may represent a substituent other than hydrogen, halogen, C1-C4 alkyl or C1-C4 alkoxy; or the pyridine N-oxides thereof, and the optical isomers thereof, and, except when R3 is a salt-forming cation, the acid addition salts thereof. 10. A method for the preparation of a compound having the structure: EMI141.1 wherein -- represents a single or a double bond; R1 is C1-C4 alkyl; R2 is C1-C4 alkyl or C3-C6 cycloalkyl; and when R1 and R2 are taken together with the carbon to which they are attached they may represent C3-C6 cycloalkyl optionally substituted with methyl; W is O or S; X is 0, S, or -S=O; Y and Y', Z and Z' are hydrogen, halogen, C1-C6 alkyl, C1-C4 hydroxyloweralkyl, C1-C6 alkoxy, C1-C6 acyloxy, benzoyloxy optionally substituted with one or two C1-C4 alkyl, C1-C4 alkoxy, halogen; C1- C4 alkylthio, phenoxy, C1-C4 haloalkyl, C1-C4 haloalkoxy, nitro, cyano, Cl-C4 alkylamino, C1-C4 dialkylamino, C1-C4 alkylsulfonyl or phenyl optionally substituted with one or two Cl-C4 alkyl, C1-C4 alkoxy, halogen, or any combination of two of these groups and wherein Y and Z are the same group provided that Y and Z are H, halogen, alkyl or alkoxy and when Y and Y' or Z and Z' are the same group they are hydrogen or alkyl; and, when taken together, Y and Z may form a ring in which YZ are represented by the structure -(CH2)n-, where n is an integer selected. from 3 or 4; or EMI142.1 where L, M, Q and R7 each represent hydrogen, halogen, nitro, C1-C4 loweralkyl, C1-C4 loweralkoxy, methoxy, phenyl and phenoxy, with the proviso that only one of L, M, Q or R7, may represent a substituent other than hydrogen, halogen, C1-C4 alkyl or C1-C4 alkoxy; or. the pyridine N-oxides thereof, and when R1 and R2 are not the same, the optical isomers thereof, and the acid addition salts thereof; comprising reacting a compound having a structure selected from: EMI142.2 wherein X, Y, Z, W, R1 and R2 are as described above, with from 2 to 20 molar equivalents of an aqueous or aqueous alcoholic sodium or potassium hydroxide at a temperature of from 25 to lOO0C and thereafter acidifying the thus-formed reaction mixture to a pH between 2 and 4 with a strong mineral acid.

Inventors: CROSS, BARRINGTON, LADNER, DAVID WILLIAM, LOS, MARINUS
Applicants: AMERICAN CYANAMID COMPANY
Application year: 1984
Main classification: C07D495
IPC codes: C07D491, C07D213, C07D333, C07D409, C07D495, A01P13, A01N43, C07D407