Reaction #66756

Reaction equation

1′-tert-butoxycarbonyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)spiro[chroman-2,4′-piperidin]-4-one

6-chloronicotinamide

Na2CO3

→

compound

tert-Butyl 6-(5-carbamoylpyridin-2-yl)-4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate

Solvents

dioxane

CHCl3

H2O

Conditions

Workup

1. 1
   Extractionthe aqueous layer was extracted with CHCl3
2. 2
   WashThe combined organic layer was washed with brine
3. 3
   Dryingdried over MgSO4 and silicagel
4. 4
   OtherThe desiccant was removed through celite filtration
5. 5
   Concentrationthe filtrate was concentrated under reduced pressure
6. 6
   OtherThe resulting residue was purified by crystallization (CHCl3-EtOAc)

Procedure

1′-tert-butoxycarbonyl-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)spiro[chroman-2,4′-piperidin]-4-one (40.0 g, 90.0 mmol), 6-chloronicotinamide (17.0 g, 108 mmol), Pd(PPh3)4 (5.21 g, 4.51 mmol), and aqueous 2M Na2CO3 (100 ml) solution were suspended in dioxane (300 ml) and heated at 100° C. for 16 h. The reaction mixture was diluted with CHCl3 and H2O, the aqueous layer was extracted with CHCl3. The combined organic layer was washed with brine, dried over MgSO4 and silicagel. The desiccant was removed through celite filtration and the filtrate was concentrated under reduced pressure. The resulting residue was purified by crystallization (CHCl3-EtOAc) to obtain the intended compound as a colorless solid.

Source