HETEROCYCLIC POLYFLUORO-COMPOUNDS .16. 2,4,5-TRIFLUORO-6-IODOPYRIMIDINE

Reaction of tetrafluoropyrimidine with sodium iodide in dimethylformamide yields 2,4,5-trifluoro-6-iodopyrimidine, 2,5-difluoro-4,6-di-iodopyrimidine, and traces of 2,4,5-trifluoropyrimidine. The last compound is formed, together with 2,5-difluoropyrimidine and a small amount of 4,5,6-trifluoropyrimidine, when tetrafluoropyrimidine is treated with lithium aluminium hydride. Methoxide ion and ammonia attack 2,4,5-trifluoro-6-iodopyrimidine at the 4-position to yield the corresponding substituted 2,5-difluoroiodopyrimidines; coupling of the 6-iodo-compound by the Ullmann technique affords perfluoro-4,4′- bipyrimidyl. Attempts to convert 2,4,5-trifluoro-6-iodopyrimidine into the corresponding Grignard reagent failed.