反应详情

A solution of 19.3 g (0.08 mol) of 2-chloro-4,5-difluoronitrobenzene in 100 g of toluene are introduced into a 200 ml three-necked flask fitted with dropping funnel, precision-ground glass stirrer and reflux condenser. 18.1 g (0.21 mol) of piperazine are added dropwise to this solution at room temperature and with stirring over the course of one hour. The mixture is then stirred at room temperature for a further 2 hours. The reaction solution formed during the reaction is washed three times with 20 ml of water in each case and dried. The solvent is removed to give 18.5 g (0.071 mmol) of 2-chloro-5-fluoro-4-piperazinonitrobenzene. This corresponds to a yield of 95%, based on 2-chloro-4,5-difluoronitrobenzene used. 2-Chloro-5-fluoro-4-piperazinonitrobenzene of the following formula ##STR5## has a melting point of 91.5° C. (purity: 92.9%, determined by HPLC).

1. customfitted
2. temperaturereflux condenser
3. stirringThe mixture is then stirred at room temperature for a further 2 hours
4. customThe reaction solution formed during the reaction
5. washis washed three times with 20 ml of water in each case
6. customdried
7. customThe solvent is removed