Potassium Carbonate → Ethyl 7-(1-(tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)imidazo[1,2-a]pyridine-3-carboxylate

HRID 1497886Notes

Reaction equation

HRID 1497886 reaction equation
Br[C:2]1[CH:7]=[CH:6][N:5]2[C:8]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[CH:9][N:10]=[C:4]2[CH:3]=1.CC1(C)C(C)(C)OB([C:24]2[CH2:29][CH2:28][N:27]([C:30]([O:32][C:33]([CH3:36])([CH3:35])[CH3:34])=[O:31])[CH2:26][CH:25]=2)O1.C([O-])([O-])=O.[K+].[K+]>CN(C=O)C.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>[C:33]([O:32][C:30]([N:27]1[CH2:26][CH:25]=[C:24]([C:2]2[CH:7]=[CH:6][N:5]3[C:8]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[CH:9][N:10]=[C:4]3[CH:3]=2)[CH2:29][CH2:28]1)=[O:31])([CH3:36])([CH3:34])[CH3:35]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 4642098Tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,2,3,6-tetrahydropyridine-1-carboxylateHCID 67260906Ethyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylate

Product 1

HCID 71280489Ethyl 7-(1-(tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)imidazo[1,2-a]pyridine-3-carboxylate

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
160 °C

Procedure

To a solution of 5-ethyl 7-bromoimidazo[1,2-a]pyridine-3-carboxylate (24g) (300 mg, 1.11 mmol) in DMF (9 mL) was added tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (414 mg, 1.34 mmol), K2CO3 (1.8M, 1.85 mL, 3.33 mmol) and Pd(PPh3)4(87 mg, 0.11 mmol). The reaction was evacuated and backfilled with nitrogen twice then heated at 160° C. for 10 minutes via microwave. After the reaction mixture was filtered through a pad of Celite, the mixture was diluted with a saturated solution of NH4Cl and extracted with ethyl acetate. The organic layer was washed with brine, dried over Na2SO4 and concentrated to give crude ethyl 7-(1-(tert-butoxycarbonyl)-1,2,3,6-tetrahydropyridin-4-yl)imidazo[1,2-a]pyridine-3-carboxylate (89) (MS (m/z) 372.1 (M+1)+.

Workup

  1. customThe reaction was evacuated
  2. filtrationAfter the reaction mixture was filtered through a pad of Celite
  3. additionthe mixture was diluted with a saturated solution of NH4Cl
  4. extractionextracted with ethyl acetate
  5. washThe organic layer was washed with brine
  6. dry with materialdried over Na2SO4
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-eb3ff360d6924f96972b9abaee6fa9ac
Source dataset
uspto-grants-2015_12
Patent number
US09199981B2

Reaction notes

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