Cesium carbonate → tert-Butyl 6-nitro-3',6'-dihydro-[3,4'-bipyridine]-1'(2'H)-carboxylate

HRID 402949Notes

Reaction equation

HRID 402949 reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH:12]=[C:11](B2OC(C)(C)C(C)(C)O2)[CH2:10][CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].Br[C:24]1[CH:25]=[CH:26][C:27]([N+:30]([O-:32])=[O:31])=[N:28][CH:29]=1.C([O-])([O-])=O.[Cs+].[Cs+]>O1CCOCC1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH:12]=[C:11]([C:24]2[CH:29]=[N:28][C:27]([N+:30]([O-:32])=[O:31])=[CH:26][CH:25]=2)[CH2:10][CH2:9]1)=[O:7])([CH3:2])([CH3:3])[CH3:4]

Participants

6

Reactant 3

HCID 10796Cesium carbonateHCID 8176205-Bromo-2-nitropyridineHCID 4642098Tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,2,3,6-tetrahydropyridine-1-carboxylate

Product 1

HCID 49840377tert-Butyl 6-nitro-3',6'-dihydro-[3,4'-bipyridine]-1'(2'H)-carboxylateYield 64%

Reagents, catalysts & solvents 2

HCID 178418476HCID 178418476, compoundCatalystHCID 312751,4-DioxaneSolvent

Procedure

A solution of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (5.38 g, 17.40 mmol), 5-bromo-2-nitro-pyridine (3.52 g, 17.40 mmol), Cs2CO3 (11.34 g, 34.8 mmol), and Pd(PPh3)2Cl2 (1.27 g, 1.74 mmol) in dioxane (50 mL) was stirred at 85° C. under N2 atmosphere overnight. TLC showed a complete reaction. The solution was poured onto water and extracted with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, and concentrated. Purification by column chromatography on silica gel (petroleum ether:ethyl acetate, 2:1 eluent) afforded the desired product as yellow solid (3.37 g, 64%). 1H NMR (300 MHz, CDCl3): δ 8.63 (d, J=2.4 Hz, 1H), 8.20 (d, J=8.4 Hz, 1H), 7.93 (dd, J=8.4, 2.4 Hz, 1H), 6.31 (s, 1H), 4.17-4.14 (m, 2H), 3.68 (t, J=5.7 Hz, 1H), 2.57-2.54 (m, 2H), 1.49 (s, 9H).

Workup

  1. customa complete reaction
  2. additionThe solution was poured onto water
  3. extractionextracted with ethyl acetate
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated
  7. customPurification by column chromatography on silica gel (petroleum ether:ethyl acetate, 2:1 eluent)

Sources & evidence

ORD record
ord-f2c0894e24594d848b17a44292ec0025
Source dataset
uspto-grants-2014_06
Patent number
US08742098B2

Reaction notes

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