Process for the production of 3-aryl-uracils

In a process for the production of compounds of the formula I

• wherein
• R1 is methyl or ethyl;
• R2 is —CF3, —CClF2, —CCl2F or —C2F5;
• and
• Q is a group
• X and Y, independently of one another, are oxygen or sulphur;
• R3 signifies hydrogen, fluorine or chlorine;
• R4 signifies hydrogen, fluorine, chlorine, bromine, cyano, nitro, methyl or difluoromethyl;
• R5 signifies hydrogen, halogen, cyano, nitro, hydroxy, C1-6-alkoxy, C1-6-alkylthio, C2-6-alkenyloxy, C2-6-alkinyloxy, C1-6-halogenalkoxy, C2-6halogen-alkenyloxy, C2-8-alkylcarbonyl-alkoxy, C2-8-alkoxycarbonylalkoxy, C1-3-alkyl-oxiranylmethoxy,
• C4-8-alkenyloxycarbonylalkoxy or C4-8-alkinyloxycarbonylalkoxy;
• R20 is hydrogen or C1-4-alkyl;
• R21 and R22, independently of one another, signify C1-4-alkyl;
• or R21 and R22 together signify a C23-alkylene bridge;
• R23 signifies cyano or COR6;
• R24 signifies hydrogen or halogen;
• R6 signifies OH, C1-6-alkoxy, C2-6-alkenyloxy, C2-6-alkinyloxy, C2-8-alkoxyalkoxy, C3-6-cycloalkoxy, C3-6-cycloalkenyloxy, C3-6-cycloalkyl-C1-6-alkoxy, C1-6-halogen-alkoxy, C2-6-halogen-alkenyloxy, C1-6-hydroxycarbonylalkoxy, C3-8-alkoxycarbonylalkoxy, C3-8-alkenyloxycarbonylalkoxy, C3-8-alkinyloxycarbonylalkoxy, N(C1-3-alkyl)2 or N(C3-4-alkenyl)2;
• R7 signifies C1-6-alkyl, C2-6-alkenyl, C2-6-alkiny], C2-8-alkoxyalkyl, C3-6-cycloalkyl, C1-6-halogenalkyl, C2-6-halogen-alkenyl, C2-6-alkylsulfonyloxyalkyl, C1-10-phenylsulfonyloxyalkyl, N(C1-5-alkyl)2 or diallylamino;
• R8 signifies hydrogen, C1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, C2-C10-alkoxyalkyl, C3-6-cycloalkyl, C3-6-cycloalkenyl, C1-6-halogen-alkyl, C3-6-halogen-alkenyl, C2-6-hydroxycarbonylalkyl, C3-8-alkoxycarbonylalkyl, C3-8-alkenyloxycarbonytalkyl or C3-8-alkinyloxycarbonylalkyl;
• R9 signifies hydrogen, OH, CH2COOR15, CH2CON(C1-4-alkyl)2, CH2CON(C3-4-alkenyl)2, COOR16, CON(C1-4-alkyl)2, CON(C3-4-alkenyl)2, C1-6-alkyl, hydroxy-C1-6-alkyl, C2-10-alkoxycarbonyl-alkoxy or C2,8-alkoxyalkyl;
• R10 signifies hydrogen, Cyano, C 1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, hydroxy-C1-6-alkyl, C2-8-alkoxyalkyl, C3-6-cycloalkyl, C1-6-halogen-alkyl, COOR17, CON(C1-4-alkyl)2 or CON(C3-4-alkenyl)2;
• R11 signifies hydrogen, C1-6-alkyl or C1-6-halogen-alkyl;
• R12 signifies hydrogen, C1-6-alkyl, C1-6-halogen-alkyl, CH2OH, C2-6-alkoxyalkyl, C2-6-halogenalkoxyalkyl, COOR18, CON(C1-4-alkyl)2 or CON(C3-4-alkenyl)2;
• R13 signifies hydrogen, C3-16-trialkylsilyloxy, C1-6-alkoxy, chlorine, C1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, C3-6-cycloalkyl, C3-6-cycloalkenyl, C1-6-halogen-alkyl, C2-6-halogen-alkenyl or C1-6-hydroxycarbonylalkyl;
• R14 signifies hydrogen, C1-6-alkyl or C1-6-halogenalkyl;
• R15 signifies hydrogen, C1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, C2-8-alkoxyalkyl, C3-6-cycloalkyl, C3-6-cycloalkenyl, C1-6-halogen-alkyl, C2-6-halogen-alkenyl, C2-6-hydroxycarbonylalkyl, C3-8-alkoxycarbonylalkyl, C3-8-alkenyloxycarbonylalkyl or C3-8-alkinyloxycarbonylalkyl;
• R16 signifies hydrogen, C1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, C2-8-alkoxyalkyl, C3-6-cycloalkyl, C3-6-cycloalkenyl, C1-6-halogen-alkyl, C2-6-halogen-alkenyl, C2-6-hydroxycarbonylalkyl, C3-8-alkoxycarbonylalkyl, C3-8-alkenyloxycarbonylalkyl or C3-8-alkinyloxycarbonylalkyl;
• R17 signifies hydrogen, C1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, C2-8-alkoxyalkyl, C3-6-cycloalkyl, C3-6-cycloalkenyl, C1-6-halogen-alkyl, C2-6-halogen-alkenyl, C2-6-hydroxycarbonylalkyl, C2-8-alkoxycarbonylalkyl, C3-8-alkenyloxycarbonylalkyl or C3-8-alkinyloxycarbonylalkyl;
• and
• R18 signifies hydrogen, C1-6-alkyl, C2-6-alkenyl, C2-6-alkinyl, C2-8-alkoxyalkyl, C3-6-cycloalkyl, C3-6-cycloalkenyl, C1-6-halogen-alkyl, C2-6-halogen-alkenyl, C2-6-hydroxycarbonylalkyl, C3-8-alkoxycarbonylalkyl, C3-8-alkenyloxycarbonylalkyl or C3-8-alkinyloxycarbonylalkyl;
• by reacting an isocyanate of the formula II
• O═C═N—Q (II)
• wherein Q has the meaning given under formula I, with an enamine of the formula III, at a temperature −5° C. to +50° C.
• wherein R1 and R2 have the meanings given under formula I in the presence of a base and in the presence of an inert solvent;
• the improvement which comprises carrying out the reaction of the isocyanate of the formula II with the enamine of the formula III in the presence of 0.1 to 0.3 equivalents of a base selected from potassium tert.butylate, sodium tert.butylate, sodium methylate, sodium ethylate, potassium methylate, potassium ethylate, sodium hydride, potassium hydride, sodium pentylate, potassium pentylate and 1,8-diazabicyclo[5.4.0]undec-7-ylene (DBU).