4-iodo-1-methyl-5-(4-(trifluoromethyl)phenyl)-1H-pyrazole synthesis

Yield:1356997-76-6 4.80 g

Reaction Conditions:

with sodium acetate;Iodine monochloride;acetic acid at 20; for 4 h;

Steps:

22 4-Iodo-1-methyl-5-[4-(trifluoromethyl)phenyl]-1H-pyrazole

Production Example 22
4-Iodo-1-methyl-5-[4-(trifluoromethyl)phenyl]-1H-pyrazole
An acetic acid (3.3 mL) solution of iodine monochloride (2.64 g) was added dropwise to an acetic acid (22 mL) solution that contained 1-methyl-5-[4-(trifluoromethyl)phenyl]-1H-pyrazole (3.70 g) and sodium acetate (1.38 g) at a room temperature, and the obtained solution was then stirred for 4 hours.
Thereafter, water (250 mL) was added to the reaction solution, and the obtained solution was then stirred for 30 minutes.
Then, a precipitated solid was collected by filtration, and was then washed with water.
The obtained solid was dissolved in ethyl acetate, and the obtained solution was then washed with water and a saturated sodium hydrogencarbonate aqueous solution.
The organic layer was dried over anhydrous sodium sulfate, and was then concentrated under a reduced pressure.
Thereafter, the residue was purified by column chromatography (silica gel 60N, hexane:ethyl acetate=5:1 to 7:3), so as to obtain the title compound (4.80 g) in the form of a brownish-red oily substance.
¹H NMR (600 MHz, CHLOROFORM-d) δ ppm 3.84 (s, 3H) 7.52 (d, J=8.25 Hz, 2H) 7.59 (s, 1H) 7.77 (d, J=7.79 Hz, 2H); MS (ESI pos.) m/z: 353 [M+H]⁺

References:

US2013/123500,2013,A1 Location in patent:Paragraph 0287; 0288