Substituteed tetrahydropyrimidine derivatives and their use as polymerization inhibitors for vinyl aromatic compounds

摘要

The present invention is directed to substituted tetrahydropyrimidine derivatives of the general formula <IMAGE> wherein R1, R2, R3, R4, R5, R6 and R7, which may be the same or different, are hydrogen or alkyl aryl, cycloalkyl, alkaryl, aralkyl or heterocyclic, or substituted derivative thereof, R6 or R7 can additionally be -OH or -NR8 wherein R8 is hydrogen, alkyl, aryl, cycloalkyl, alkaryl, aralkyl or heterocyclic, or substituted derivative thereof, or R6 and R7 together can be =O or =NOH, and any two R groups on the same or adjacent carbon atoms can be joined in a cyclic configuration, and X is oxyl or hydroxy, it being provided that at least one of R2 and R3 and at least one of R4 and R5 are other than hydrogen.