4- chloro-2-fluoro-6-methylpyrimidine

The Levafix P dyes have been replaced by the Levafix PN (DyStar) range, which is based on the 5 chloro-2-fluorO 4-methylpyrimidine system. These two systems are essentially similar, but the Levafix PN dyes have a fluorine atom as the labile entity rather than the methylsulphonyl grouping. The necessary intermediate 5-chloro-2,6-difluoro-4-methyl-pyrimidine (7.25) can be made from 4-methyl-2,5,6-trichloropyrimidine by an exchange reaction with potassium fluoride (Scheme 7.20). Condensation with the dye base (Scheme 7.21) will give a mixture of isomers, namely, the 5 chloro-6-fluoro-4-methyl (7.26) and 5-chloro-2-fluoro-4-methyl (7.27) derivatives. 

---