Method for producing 4,6-dichloro-5-fluoropyrimidine
View Patent ↗The invention relates to a novel process for preparing 4,6-dichloro-5-pyrimidine.
1. A process for preparing the compound of formula (I)
comprising reacting 4,6-dihydroxy-5-fluoropyrimidine of formula (II) or an alkali metal salt thereof
with phosgene in the presence of nitrobenzene as solvent, optionally in the presence of a catalyst, and optionally in the presence of a phase transfer catalyst.
2. A process according to claim 1 in which the catalyst is 4-dimethylaminopyridine.
3. A process according to claim 1 carried out without a catalyst and without a phase transfer catalyst.
4. A process according to claim 1 carried out using 4-dimethylaminopyridine as a catalyst but without a phase transfer catalyst.
5. A process according to claim 1 carried out at temperatures from 40° C. up to the reflux temperature of the reaction mixture.
6. A process according to claim 1 in which from 2 to 20 mol of phosgene are used per mole of the compound of formula (II).
7. A process according to claim 1 in which from 0 to 30 mol% of the catalyst are used per mole of the compound of formula (II).