Reaction #657317

Reaction equation

sodium carbonate

N-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]cyclopropanecarboxamide

7-bromo-6-(4-fluorophenyl)-2,3-dihydropyrazolo[5,1-b][1,3]oxazole

→

N-{4-[6-(4-fluorophenyl)-2,3-dihydropyrazolo[5,1-b][1,3]oxazol-7-yl]pyridin-2-yl}cyclopropanecarboxamide

Yield 61.7%

Solvents

1,4-dioxan

Conditions

Workup

1. 1
   OtherThe reaction mixture is flushed for 5 mins with argon
2. 2
   Othersealed
3. 3
   TemperatureAfter cooling
4. 4
   Filtrationinsoluble components are filtered off
5. 5
   Washthe salt residue washed with 1,4-dioxan
6. 6
   OtherThe organic phase is evaporated
7. 7
   Otherthe crude product purified by silica gel chromatography (eluent cyclohexane/ethyl acetate)

Procedure

115 mg (0.40 mmol) of N-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-yl]cyclopropanecarboxamide and 124 mg (1.1 eq 0.44 mmol) of 7-bromo-6-(4-fluorophenyl)-2,3-dihydropyrazolo[5,1-b][1,3]oxazole are dissolved in 2 mL 1,4-dioxan. To this are added 30 mg of bis(tricyclohexylphosphine)-palladium(II)dichloride (0.04 mmol, 0.1 eq) and 2 mL sodium carbonate solution (2M in H2O). The reaction mixture is flushed for 5 mins with argon and then sealed. Next the mixture is heated for 12 mins at 120° C. in the microwave (CEM Explorer). After cooling, insoluble components are filtered off and the salt residue washed with 1,4-dioxan. The organic phase is evaporated and the crude product purified by silica gel chromatography (eluent cyclohexane/ethyl acetate). 90 mg (61%) of N-{4-[6-(4-fluorophenyl)-2,3-dihydropyrazolo[5,1-b][1,3]oxazol-7-yl]pyridin-2-yl}cyclopropanecarboxamide are obtained as a colourless solid.

Source