Process for preparing a 2-alkyl- or 2-phenyl-1,4,5,6-tetrahydropyrimidineand and process for the preparation of 2-alkyl- or 2-phenyl- pyrimidines

摘要

The invention relates to a process for preparing a 2-alkyl-1,4,5,6-tetrahydropyrimidine with the formula where R represents a straight or branched chain with 1-8 C-atoms or a phenyl group from 1,3-diaminopropane and an alkanecarboxylic acid, in which the alkyl group of such an acid is the same as the R group described above, in which process the starting materials are reacted in the gas phase in the presence of an oxide catalyst at a temperature of between 250 and 450◊C and from the reaction mixture thus obtained the 2-alkyl-1,4,5,6-tetrahydropyrimidine is recovered.