On the Mechanism of Condensation between 5-Amino-4, 6-dichloro- 2-methylpyrimidine and 1-Acetyl-2-imidazolin-2-one

The condensation reaction between 5-amino-4, 6-dichloro-2-methylpyrimidine and 1-acetyl-2-imidazolin-2-one using POCl3 as solvent gave 4, 6-dichloro-2-methyl-5-(1-acetyl-tetra-hydro-imidazo-2-ylidene)- aminopyrimidine predominantly and 4, 6-dichloro-2-methyl-5-{1-[1-(2-oxo-tetrahydro-imidazolyl)]-acetyene}- aminopyrimidine as by-product. No 4, 6-dichloro-2-methyl-5-(1-acetyl-2-imidazolin-2-yl)-aminopyrimidine was found. The result indicated an esterifi- cation-addition-elimination mechanism