2-Bromopyridine → tert-Butyl 5',6'-dihydro-[2,4'-bipyridine]-1'(2'H)-carboxylate

HRID 1403616Notes

Reaction equation

CC1(C)C(C)(C)OB([C:9]2[CH2:14][CH2:13][N:12]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:11][CH:10]=2)O1.Br[C:24]1[CH:29]=[CH:28][CH:27]=[CH:26][N:25]=1.[O-]P([O-])([O-])=O.[K+].[K+].[K+]>O1CCOCC1.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[N:25]1[CH:26]=[CH:27][CH:28]=[CH:29][C:24]=1[C:9]1[CH2:14][CH2:13][N:12]([C:15]([O:17][C:18]([CH3:19])([CH3:20])[CH3:21])=[O:16])[CH2:11][CH:10]=1

Participants

Conditions

Temperature: 90 °C

Procedure

To a solution of tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (1 g, 3.23 mmol) in dioxane (35 ml) and water (2.0 ml) was added 2-bromopyridine (2.9 g, 18.35 mmol), K3PO4 (3.8 g, 17.90 mmol) and Pd(PPh3)4 (350 mg, 0.30 mmol), and the resulting mixture was allowed to react with stirring for 3 hours at 90° C. The reaction mixture was diluted with water (180 ml) and extracted with ethyl acetate (3×50 ml). The organic layers were combined, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure to give the residue, which was purified via silica gel column chromatography (2% ethyl acetate in petroleum ether) to afford tert-butyl 4-(pyridin-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate as pink oil (1.1 g, 70%).

Workup

customto react
extractionextracted with ethyl acetate (3×50 ml)
dry with materialdried over anhydrous magnesium sulfate
concentrationconcentrated under reduced pressure
customto give the residue, which
customwas purified via silica gel column chromatography (2% ethyl acetate in petroleum ether)

Sources & evidence

ORD record: ord-777160b193f540f2a315fca22ed2c5e4
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08912188B2

Reaction notes

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