Patent GB-1060741-A (GB)
Title: Improvements in or relating to oxazinone derivatives
IPC: C07D239/54
Filed: 1964-02-26
Abstract: Novel oxazine derivatives having one of the three tautomeric formulae <FORM:1060741/C2/1> wherein R1 represents hydrogen, C1- 10 alkyl, C1- 8 substituted alkyl (e.g. chloro, bromo, hydroxy, alkoxy, alkoxycarbonyl or cyano-substituted alkyl), C6- 10 aryl, substituted phenyl (e.g. alkyl, haloalkyl, haloalkoxy, halogen or nitro substituted phenyl), C7- 13 aralkyl or substituted aralkyl, C3- 8 alkenyl, C3- 8 alkynyl, furfuryl, C3- 12 cycloalkyl, C4- 12 cycloalkenyl, C4- 13 cycloalkyl-alkyl, C5- 13 cycloalkenyl-alkyl, C4- 14 substituted cycloalkyl, C4- 14 substituted cycloalkenyl, C4- 14 (substituted cycloalkyl) alkyl or C5- 14 (substituted cycloalkenyl) alkyl; R2 represents hydrogen, chlorine, bromine, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, tert.-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec.-butoxy or tert.-butoxy; R3 represents C1- 5 alkyl, C1- 4 chloroalkyl or C1- 4 bromoalkyl; or R2 and R3 taken together represent -(CH2)n-, where n is 3, 4 or 5; and salts thereof; are prepared by reacting a substituted beta-aminocrotonamide of the formula <FORM:1060741/C2/2> with phosgene.  Products in which R2 represents hydrogen may be subsequently halogenated to form compounds in which R2 represents a halogen atom.  Uracils of the formula <FORM:1060741/C2/3> are prepared by reacting oxazines of the above formulae with an inorganic base and, if necessary, an acidifying agent.  Beta-crotonamides of the formula <FORM:1060741/C2/4> are prepared by reacting diketene with an amine R1NH2 to form a substituted acetoacetamide of the formula <FORM:1060741/C2/5> which is then reacted with ammonia.ALSO:The growth of undesired vegetation may be destroyed or inhibited by applying thereto oxazine derivatives having one of the three tantomeric formulae: <FORM:1060741/A5-A6/1> wherein R1 represents hydrogen, C1-10 alkyl, C1-8 substituted alkyl, C6-10 aryl, substituted phenyl, C7-13 aralkyl or substituted aralkyl, C3-8 alkenyl, C3-8 alkynyl, furfuryl, C3-12 cycloalkyl, C4-12 cycloalkenyl, C4-13 cycloalkylalkyl, C5-13 cycloalkenyl-alkyl, C4-14 substituted cycloalkyl, C4-14 substituted cycloalkenyl, C4-14 (substituted cycloalkyl) alkyl, or C4-14 (substituted cycloalkenyl) alkyl; R2 represents hydrogen, chlorine, bromine, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.-butyl, tert.-butyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy or tert.-butoxy; R3 represents C1-5 alkyl, C1-4 chloroalkyl or C1-4 bromoalkyl; or R2 and R3 taken together represent -(CH2)n-, where n is 3, 4 or 5; and salts thereof; either as such or in admixture with suitable formulating agents or other specified herbicides chosen from substituted ureas, e.g. 3-(3,4-dichlorophenyl)-1,1-dimethylurea; substituted triazines, e.g. 2-chloro - 4,6 - bis (ethylamino) - s - triazine; phenols, e.g. dinitro-ortho-sec. butylphenol an pentachlorophenol, and salts thereof; various carboxylic acids and their derivatives, e.g. 2,3,6-trichlorobenzoic acid, 2,4-dichlorophenoxyacetic acid, 2,3,6-trichlorobenzyloxypropanol, 2,6-dichlorobenzonitrile, trichloroacetic acid, ethyl N,N-di(n-propyl) thiolcarbamate, isopropyl N-phenylcarbamate, 2-chloro-N,N diallylacetamide, and maleic hydrazide; substituted uracils, e.g. 3-cyclohexyl-6-methyluracil; other organic compounds such as 5,6-dihydro-(4A, 6A)-dipyrido-(1, 2-A, 2\sv, 1\sv-C) pyrazinium dibromide, 3-amino-1,2,4-triazole, 3,6-endoxohexahydrophthalic acid, hexachloroacetone, diphenylacetonitrile, N,N - dimethyl - a ,a  - diphenylacetamide, N,N-di-n-propyl-2,6-dinitro-4-trifluoromethylaniline, N,N-di-n-propyl-2-6-dinitro-4 methylaniline, O-(2,4-dichlorophenyl) - O - methylisopropyl - phosphoramidothrate, dimethyl 2,3,5,6-tetrachloroterephthalate, dimethyl arisinic acid and 2,4-dichloro-4\sv-nitrodiphenyl ether; and inorganic or mixed inorganic-organic salts such as arsonates, arsenites, arsenates, borates, borchlorates, thiocyanates, chlorates and sulphanates.