Patent ID: 7230104

Claim:
A process for the preparation of a pyrimidine of formula I in which R 1 represents C 1 –C 10 -alkyl, C 1 –C 10 -haloalkyl, C 2 –C 6 -alkenyl, C 2 –C 6 -alkynyl, C 4 –C 8 -alkadienyl, C 1 –C 10 -alkoxy, C 3 –C 8 -cycloalkyl, phenyl, tri-C 1 –C 6 -alkyl-silyl, formyl or C 1 –C 10 -alkoxy carbonyl, wherein R 1 groups are unsubstituted or substituted by one to three groups R a ; R a is halogen, nitro, cyano, hydroxy, or is C 1 –C 10 -alkyl, C 3 –C 6 -cycloalkyl, C 3 –C 6 -cycloalkenyl, C 1 –C 10 -haloalkyl, C 3 –C 6 -halocycloalkyl, C 1 –C 10 -alkoxy, C 1 –C 10 -haloalkoxy, C 1 –C 10 -alkoxycarbonyl, tri-C 1 –C 4 -alkylsilyl, phenyl, halo- or dihalophenyl; R 2 represents phenyl or C 3 –C 6 -cycloalkyl which are unsubstituted or substituted by one to three groups R a ; R 3 represents hydrogen, halogen, or is C 1 –C 10 -alkyl, C 1 –C 10 -alkoxy, C 1 –C 10 -alkylthio, C 1 –C 10 -alkylamino or di-C 1 –C 10 -alkylamino, which are unsubstituted or substituted by one to three groups R a ; R 4 represents C 1 –C 10 -alkyl, C 2 –C 6 -alkenyl or C 2 –C 6 -alkynyl; which are unsubstituted or substituted by one to three groups R a ; and X represents O, S, NR 5 or a single bond, wherein R 5 represents hydrogen, C 1 –C 10 -alkyl or C 1 –C 10 -haloalkyl; or R 1 and R 5 together with the interjacent nitrogen atom form a heterocyclic ring selected from the group consisting of pyrrolidine, piperidine, tetrahydropyridine and azepane, which ring is optionally substituted by one or more C 1 –C 10 -alkyl groups, which process comprises reacting a sulfone of formula VI in which R 6 is C 1 –C 6 -alkyl or C 1 –C 6 -haloalkyl; with an alkylated cyanamide of formula VII wherein the sulfone of formula VI is obtained by reacting a 2-thiopyrimidine compound of formula VIII with an oxidizing agent.