Réaction #1965635

Équation de réaction

6-bromo-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

Intermediate 1

6-bromo-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

3-(triethoxysilyl)furan

1,4-diazabicyclo(2.2.2)octane

tetrabutylammonium fluoride

3-(triethoxysilyl)furan

DABCO

→

6-(3-furyl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide

Solvants

tetrahydrofuran

dioxane

Conditions de réaction

Traitement

1. 1
   TempératureThe reaction mixture is heated for 3 hours in a microwave machine
2. 2
   Autreset at 120° C.
3. 3
   Températurethe mixture is heated for a further 1.5 hours in a microwave machine
4. 4
   Autreset at 150° C.
5. 5
   Températurecooled
6. 6
   Filtrationfiltered
7. 7
   ConcentrationThe filtrate is concentrated to dryness under reduced pressure
8. 8
   Autrethe residue is chromatographed on a silica cartridge
9. 9
   Lavageeluting with dichloromethane
10. 10
    workup.ADDITIONThe fractions containing the pure expected product
11. 11
    Autreevaporated to dryness under reduced pressure
12. 12
    workup.DISSOLUTIONThe solid is dissolved while
13. 13
    workup.ADDITIONhot in a mixture of dichloromethane and methanol
14. 14
    FiltrationThe hot solution is filtered
15. 15
    workup.ADDITIONtreated with diisopropyl ether
16. 16
    AutreThe precipitate formed
17. 17
    Filtrationis filtered off by suction
18. 18
    Autredried

Mode opératoire

200 mg of 6-bromo-N-phenylimidazo[1,2-a]pyridine-2-carboxamide (Intermediate 1), 10 mL of dioxane, 400 μL of 3-(triethoxysilyl)furan, 42 mg of palladium acetate, 42 mg of 1,4-diazabicyclo(2.2.2)octane (DABCO) and 1.5 mL of a molar solution of tetrabutylammonium fluoride in tetrahydrofuran are placed in a microwave tube. The reaction mixture is heated for 3 hours in a microwave machine set at 120° C., 200 μL of 3-(triethoxysilyl)furan, 20 mg of palladium acetate and 20 mg of DABCO are then added and the mixture is heated for a further 1.5 hours in a microwave machine set at 150° C. and then cooled and filtered. The filtrate is concentrated to dryness under reduced pressure and the residue is chromatographed on a silica cartridge, eluting with dichloromethane. The fractions containing the pure expected product are combined and evaporated to dryness under reduced pressure. The solid is dissolved while hot in a mixture of dichloromethane and methanol. The hot solution is filtered and treated with diisopropyl ether. The precipitate formed is filtered off by suction and dried to give 25 mg of 6-(3-furyl)-N-phenylimidazo[1,2-a]pyridine-2-carboxamide in the form of a yellow solid.

Source