Reaction #2254184

Reaction equation

Pyridine-4-boronic acid

3-(5-bromo-4-methyl-thiophen-2-yl)-5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole

K2CO3

→

4-{5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophen-2-yl}-pyridine

Yield 40.2%

Solvents

THF

water

Conditions

Workup

1. 1
   Otherthe reaction is quenched with water
2. 2
   Extractionextracted three times with ethyl acetate
3. 3
   Dryingdried over MgSO4
4. 4
   Concentrationconcentrated in vacuo
5. 5
   OtherThe crude product is purified on a semi-preparative HPLC

Procedure

, Pyridine-4-boronic acid (30 mg) is added to a solution of 3-(5-bromo-4-methyl-thiophen-2-yl)-5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazole (100 mg), K2CO3 (90 mg) and Pd(PPh3)4 (20 mg) in a mixture of THF and water (0.4 ml, 9:1). After 22 hours at 70° C., the reaction is quenched with water and extracted three times with ethyl acetate. The organic phases are combined, dried over MgSO4 and concentrated in vacuo. The crude product is purified on a semi-preparative HPLC to yield 4-{5-[5-(3,5-dichloro-phenyl)-5-trifluoromethyl-4,5-dihydro-isoxazol-3-yl]-3-methyl-thiophen-2-yl}-pyridine (40 mg) as a colorless oil. MS (HPLC/MS): 457 (MH+). Retention time: 5.20 min.

Source