Hydrochloric Acid → (3-amino-2-phenoxymethyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrazin-5-yl)-(4-fluoro-phenyl)-methanone

HRID 2369611Notes

Reaction equation

HRID 2369611 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([N:10]2[CH2:15][CH2:14][N:13]3[N:16]=[C:17]([CH2:20][O:21][C:22]4[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=4)[C:18](I)=[C:12]3[CH2:11]2)=[O:9])=[CH:4][CH:3]=1.CC(C)([O-])C.[Na+].C1(P(C2C=CC=CC=2)C2C=CC3C(=CC=CC=3)C=2C2C3C(=CC=CC=3)C=CC=2P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C(=[NH:93])(C1C=CC=CC=1)C1C=CC=CC=1.Cl>C1(C)C=CC=CC=1.C([O-])([O-])=O.[Na+].[Na+].O.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]>[NH2:93][C:18]1[C:17]([CH2:20][O:21][C:22]2[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=2)=[N:16][N:13]2[CH2:14][CH2:15][N:10]([C:8]([C:5]3[CH:6]=[CH:7][C:2]([F:1])=[CH:3][CH:4]=3)=[O:9])[CH2:11][C:12]=12

Participants

10

Reactant 5

HCID 313Hydrochloric AcidHCID 136809Benzophenone imineHCID 634876Binap, (A+-)-HCID 23676156Sodium t-butoxideHCID 67958487(4-fluoro-phenyl)-(3-iodo-2-phenoxymethyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrazin-5-yl)-methanone

Product 1

HCID 67960216(3-amino-2-phenoxymethyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrazin-5-yl)-(4-fluoro-phenyl)-methanoneYield 49.1%

Reagents, catalysts & solvents 4

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 962WaterSolventHCID 1140TolueneSolventHCID 10340Sodium CarbonateSolvent

Procedure

Tris(dibenzylideneacetone)dipalladium(0) (9.6 mg, 0.01 mmol) was added to a stirred suspension of (4-fluoro-phenyl)-(3-iodo-2-phenoxymethyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrazin-5-yl)-methanone (50 mg, 0.1 mmol), sodium tert-butoxide (30 mg, 0.31 mmol) and rac-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (19.6 mg, 0.031 mmol) in toluene (2 mL) in a sealed tube and under N2. The mixture was stirred at room temperature for 5 minutes and then benzophenone imine (0.035 mL, 0.21 mmol) was added. The mixture was stirred at 100° C. for 2.5 hours. Then a 1M aqueous solution of HCl (3 mL) was added and the mixture was stirred at room temperature for 16 hours. The mixture was diluted with a saturated solution of Na2CO3 and water and extracted with DCM. The organic layer was separated, dried (MgSO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; MeOH in DCM 0/100 to 6/94). The desired fractions were collected and the solvents evaporated in vacuo. The desired product was triturated with diethyl ether to yield (3-amino-2-phenoxymethyl-6,7-dihydro-4H-pyrazolo[1,5-a]pyrazin-5-yl)-(4-fluoro-phenyl)-methanone (18 mg, 47% yield) as a white solid. C20H19FN4O2 1H NMR (500 MHz, CDCl3) δ ppm 1.53 (s, 1H), 2.86 (br. s., 1H), 3.99 (br. s., 2H), 4.18 (br. s., 2H), 4.70 (br. s., 2H), 5.08 (s, 2H), 6.97 (t, J=7.4 Hz, 1H), 7.02 (d, J=8.1 Hz, 2H), 7.15 (t, J=8.7 Hz, 2H), 7.30 (dd, J=8.4, 7.5 Hz, 2H), 7.49 (dd, J=8.5, 5.3 Hz, 2H).

Workup

  1. stirringThe mixture was stirred at 100° C. for 2.5 hours
  2. stirringthe mixture was stirred at room temperature for 16 hours
  3. extractionextracted with DCM
  4. customThe organic layer was separated
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. customthe solvents evaporated in vacuo
  8. customThe crude product was purified by flash column chromatography (silica; MeOH in DCM 0/100 to 6/94)
  9. customThe desired fractions were collected
  10. customthe solvents evaporated in vacuo
  11. customThe desired product was triturated with diethyl ether

Sources & evidence

ORD record
ord-18baf16e19c44b0dbd069db0a435eb4b
Source dataset
uspto-grants-2014_04
Patent number
US08703946B2

Reaction notes

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