反应详情

温度

150 °C

96.3 g (1660 mmol) of spray-dried potassium fluoride were carefully dried under high vacuum. 129.2 g (664 mmol) of 5-chloro-1-methyl-3-difluoromethyl-1H-pyrazole-4-carbaldehyde (II-1) in 1 L of DMF were added. The reaction mixture was heated to 150° C. with rapid stirring. The reaction is complete after 3 hours (GC check). The reaction mixture is cooled down to room temperature and bulked with water to a total volume of 4 L. The reaction mixture is washed twice with 2000 ml of ethyl acetate each time. The combined organic phases were subsequently washed with saturated sodium chloride solution, dried over sodium sulphate and concentrated to obtain 117.6 g (90% of theory, purity 90%) of 5-fluoro-1-methyl-3-difluoromethyl-1H-pyrazole-4-carbaldehyde (IV-1) in the form of a brown solid which is further reacted without further purification.

1. temperatureThe reaction mixture is cooled down to room temperature
2. washThe reaction mixture is washed twice with 2000 ml of ethyl acetate each time
3. washThe combined organic phases were subsequently washed with saturated sodium chloride solution
4. dry with materialdried over sodium sulphate
5. concentrationconcentrated