反应详情

温度

23 °C

A mixture of commercially available 1-(4-chlorophenyl)-4,4,4-trifluoro-1,3-butanedione (8.65 g, 34.52 mmol) and commercially available 3-aminopyrazole (2.87 g, 34.52 mmol) in acetic acid (70 mL) was refluxed for 3 h (intermediate 5-(4-chloro-phenyl)-7-trifluoromethyl-pyrazolo[1,5-a]pyrimidine). Cooled to 23° C., added sodium acetate (3.54 g, 43.2 mmol) and a solution of iodine monochloride (2.11 mL, 41.4 mmol) in acetic acid (12 mL) was added dropwise, whereupon the reaction mixture solidified 2 min after complete addition. Added acetic acid (50 mL) and the mixture was stirred at 23° C. for additional 1 h. Diluted slowly with water (up to 400 mL), stirred at 23° C. for 30 min, the precipitate was filtered off, washed with water and dried in air at 50° C. to give a yellow solid, which was dissolved in EtOAc, washed with sat. NaHCO3-sol. and sat. Na2SO3-sol. and brine, dried over Na2SO4. Removal of the solvent in vacuum gave 5-(4-chloro-phenyl)-3-iodo-7-trifluoromethyl-pyrazolo[1,5-a]pyrimidine as a yellow solid (14.30 g, 98%). MS (EI) 422.9 [(M)+] and 425.0 [(M+2)+]; mp 155° C.

1. additionafter complete addition
2. filtrationthe precipitate was filtered off
3. washwashed with water
4. customdried in air at 50° C.
5. customto give a yellow solid, which
6. washwashed with sat. NaHCO3-sol
7. dry with materialand brine, dried over Na2SO4
8. customRemoval of the solvent in vacuum