Studies on pyrimidine derivatives. VII. Nickel-phosphine complex-catalyzed Grignard coupling of chloropyrimidines

In the presence of a nickel phosphine complex, the coupling reaction of Grignard reagents with chloropyrimidines such as 2-chloro-4, 6-dimethyl-(III), 4-chloro-2, 6-dimethyl-(V), 4, 6-dichloro-2-methyl-(VIII), 2, 4-dichloro-6-methyl-(X), and 2, 4, 6-trichloro-pyrimidine (XIII) was studied to give the corresponding alkyl (or arkyl) substituted pyrimidines in yields ranging from 40 to 88%. Although in the cases of VIII, X, and XIII, the selectivity on the reaction due to the position of the chloride atom was not observed, this coupling was concluded to remove the defects of the Pinner reaction for the synthesis of polyalkyl (or polyaryl) pyrimidines.