Potassium Carbonate → 2-(Pyridin-2-yl)-3-(imidazo[1,2-a]pyridin-6-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole

HRID 751295Notes

Reaction equation

HRID 751295 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([CH:8]=[CH:9][N:10]=2)[CH:7]=1.[N:11]1[N:12]2[CH2:21][CH2:20][CH2:19][C:13]2=[C:14](B(O)O)[CH:15]=1.C(=O)([O-])[O-].[K+].[K+].C(O[CH2:32][CH3:33])(=O)C.CO>CS(C)=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:6]1[CH:33]=[CH:32][CH:3]=[CH:4][C:5]=1[C:15]1[C:14]([C:2]2[CH:3]=[CH:4][C:5]3[N:6]([CH:8]=[CH:9][N:10]=3)[CH:7]=2)=[C:13]2[CH2:19][CH2:20][CH2:21][N:12]2[N:11]=1

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 27955476-Bromoimidazo[1,2-a]pyridineHCID 21584119Ethylacetate methanolHCID 72213308(5,6-Dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl)boronic acid

Product 1

HCID 103801302-(Pyridin-2-yl)-3-(imidazo[1,2-a]pyridin-6-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazoleYield 38%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 679Dimethyl SulfoxideSolvent

Procedure

Add tetrakis(triphenylphosphine)palladium(0) (0.025 g, 0.022 mmol) to a microwave tube containing a solution of 6-bromo-imidazo[1,2-a]pyridine (0.086 g, 0.44 mmol), 2-pyridin-2-yl)-5,6-dihydro-4H-pyrrolo[1,2-b]pyrazole-3-boronic acid (Preparation 5; 0.1 g, 0.436 mmol), and 2M aqueous potassium carbonate (0.5 mL, 1 mmol) in dimethylsulfoxide (1.5 mL). Irradiate the reaction in a microwave reactor set at 111° C., 50 W., 10 min with internal cooling. Normal phase chromatography using ethyl acetate/methanol mixtures followed by reversed phase preparative chromatography gives the 0.05 g (38%) of the title compound as a white solid. MS (electrospray, m/z) 301.9 (M+1). 1H NMR (400 MHz, DMSO-d) δ 8.57 (s, 1H), 8.4 (d, J=4.8 Hz, 1H), 7.87 (s, 1H), 7.78 (m, 2H), 7.52 (s, 1H), 7.42 (d, J=9.2 Hz, 1H), 7.26 (m, 1H), 7.05 (dd, J=9.2, 2 Hz, 1H), 4.2 (t, J=6.6 Hz, 2H, 2.99 (t, J=6.6 Hz, 2H), 2.59 (m, 1H).

Workup

  1. customIrradiate
  2. customthe reaction in a microwave reactor
  3. customset at 111° C.
  4. custom10 min

Sources & evidence

ORD record
ord-b7eea4a5c2094840b71aa730bd400bde
Source dataset
uspto-grants-2008_07
Patent number
US07405299B2

Reaction notes

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