Cesium carbonate → 5-Bromo-3-(6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazin-2-ylamino)-1-methylpyridin-2(1H)-one

HRID 407713Notes

Reaction equation

HRID 407713 reaction equation
[N:1]1[N:9]2[C:4]([CH2:5][O:6][CH2:7][CH2:8]2)=[CH:3][C:2]=1[NH2:10].Br[C:12]1[C:13](=[O:20])[N:14]([CH3:19])[CH:15]=[C:16]([Br:18])[CH:17]=1.C(=O)([O-])[O-].[Cs+].[Cs+].CC1(C)C2C(=C(P(C3C=CC=CC=3)C3C=CC=CC=3)C=CC=2)OC2C(P(C3C=CC=CC=3)C3C=CC=CC=3)=CC=CC1=2>C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].O1CCOCC1>[Br:18][C:16]1[CH:17]=[C:12]([NH:10][C:2]2[CH:3]=[C:4]3[CH2:5][O:6][CH2:7][CH2:8][N:9]3[N:1]=2)[C:13](=[O:20])[N:14]([CH3:19])[CH:15]=1

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 6360441,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine)HCID 36143503,5-Dibromo-1-methylpyridin-2(1H)-oneHCID 580437996,7-dihydro-4H-pyrazolo(5,1-c)(1,4)oxazin-2-amine

Product 1

HCID 670161895-Bromo-3-(6,7-dihydro-4H-pyrazolo[5,1-c][1,4]oxazin-2-ylamino)-1-methylpyridin-2(1H)-oneYield 31%

Reagents, catalysts & solvents 2

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 312751,4-DioxaneSolvent

Procedure

A 50-mL three-neck round-bottomed flask equipped with a magnetic stirrer, reflux condenser and nitrogen inlet was charged with 1,4-dioxane (20 mL), 131b (600 mg, 4.31 mmol), 3,5-dibromo-1-methylpyridine-2(1H)-one (1.44 g, 5.40 mmol) and cesium carbonate (3.08 g, 9.48 mmol). After bubbling nitrogen through the resulting solution for 30 min, Xantphos (300 mg, 0.52 mmol) and tris(dibenzylideneacetone)dipalladium(0) (320 mg, 0.35 mmol) were added, and the reaction mixture was heated at reflux for 2 h. After this time the reaction was cooled to room temperature, partitioned between ethyl acetate (75 mL) and water (75 mL) and filtered. The aqueous layer was separated and extracted with ethyl acetate (2×25 mL). The organic layers were combined and washed with brine (50 mL) and dried over sodium sulfate. The drying agent was removed by filtration and the filtrate concentrated under reduced pressure. The resulting residue was purified by column chromatography using 500 cc of silica gel and eluting with 1% methanol in methylene chloride. The fractions were collected to afford, after concentrating under reduced pressure, a 31% yield (433 mg) of 131c as a green solid: mp 195-197° C.; 1H NMR (300 MHz, CDCl3) 7.92 (d, 1H, J=2.4 Hz), 7.44 (s, 1H), 6.90 (d, 1H, J=2.4 Hz), 5.65 (s, 1H), 4.80 (s, 2H), 4.13 (s, 2H), 3.61 (s, 5H); MS (ESI+) m/z 324.9 (M+H).

Workup

  1. customA 50-mL three-neck round-bottomed flask equipped with a magnetic stirrer
  2. temperaturereflux condenser and nitrogen inlet
  3. customAfter bubbling nitrogen through the resulting solution for 30 min
  4. temperaturethe reaction mixture was heated
  5. temperatureat reflux for 2 h
  6. custompartitioned between ethyl acetate (75 mL) and water (75 mL)
  7. filtrationfiltered
  8. customThe aqueous layer was separated
  9. extractionextracted with ethyl acetate (2×25 mL)
  10. washwashed with brine (50 mL)
  11. dry with materialdried over sodium sulfate
  12. customThe drying agent was removed by filtration
  13. concentrationthe filtrate concentrated under reduced pressure
  14. customThe resulting residue was purified by column chromatography
  15. washeluting with 1% methanol in methylene chloride
  16. customThe fractions were collected
  17. customto afford
  18. concentrationafter concentrating under reduced pressure

Sources & evidence

ORD record
ord-1b830e6c9be144ec9119ae33001b3098
Source dataset
uspto-grants-2014_06
Patent number
US08754077B2

Reaction notes

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