Hydrochloric Acid → 6-chloro-4-(5-methyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-ylamino)pyridazin-3(2H)-one

HRID 1907789Notes

Reaction equation

HRID 1907789 reaction equation
[CH3:1][N:2]1[CH2:7][CH2:6][N:5]2[N:8]=[C:9]([NH2:11])[CH:10]=[C:4]2[CH2:3]1.Br[C:13]1[C:14](=[O:20])[NH:15][N:16]=[C:17]([Cl:19])[CH:18]=1.[Li+].C[Si]([N-][Si](C)(C)C)(C)C.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.Cl>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].O.C1COCC1.O1CCOCC1>[Cl:19][C:17]1[CH:18]=[C:13]([NH:11][C:9]2[CH:10]=[C:4]3[CH2:3][N:2]([CH3:1])[CH2:7][CH2:6][N:5]3[N:8]=2)[C:14](=[O:20])[NH:15][N:16]=1

Participants

10

Reactant 5

HCID 313Hydrochloric AcidHCID 6360441,1'-(9,9-Dimethyl-9H-xanthene-4,5-diyl)bis(1,1-diphenylphosphine)HCID 2733832Lithium HexamethyldisilazideHCID 115865224-Bromo-6-chloro-2,3-dihydropyridazin-3-oneHCID 580439335-methyl-4H,5H,6H,7H-pyrazolo[1,5-a]pyrazin-2-amine

Product 1

HCID 585403166-chloro-4-(5-methyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-ylamino)pyridazin-3(2H)-oneYield 74.8%

Reagents, catalysts & solvents 4

HCID 9811564Bis(dibenzylideneacetone)palladiumCatalystHCID 962WaterSolventHCID 8028TetrahydrofuranSolventHCID 312751,4-DioxaneSolvent

Procedure

A 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer, reflux condenser and nitrogen inlet was charged with 1,4-dioxane (5.0 mL), 5-methyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine (152 mg, 1.00 mmol), 4-bromo-6-chloropyridazin-3(2H)-one (209 mg, 1.00 mmol) and a 1 M THF solution of LiHMDS (5.0 mL, 5.00 mmol). After bubbling nitrogen through the resulting solution for 30 min, Xantphos (49 mg, 0.05 mmol) and tris(dibenzylideneacetone)dipalladium(0) (59 mg, 0.085 mmol) were added, and the reaction mixture was heated at reflux for 3 h. After this time, the reaction was cooled to room temperature, and water (10 mL) was added, The pH was adjusted to 6.5 with 2 N hydrochloric acid. The resulting precipitate was collected by vacuum filtration, washed with water (2×25 mL), absorbed on silica gel and purified by flash chromatography to afford a 74% yield (210 mg) of 6-chloro-4-(5-methyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-ylamino)pyridazin-3(2H)-one as a light brown solid: 1H NMR (300 MHz, DMSO-d6) δ 12.94 (s, 1H), 9.55 (s, 1H), 7.68 (s, 1H), 5.96 (s, 1H), 4.04 (t, 1H, J=5.7 Hz), 3.53 (s, 2H), 2.82 (t, 2H, J=5.7 Hz), 2.36 (s, 3H); MS (ESI+) m/z 281.1 (M+H).

Workup

  1. customA 50-mL single-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 3 h
  6. filtrationThe resulting precipitate was collected by vacuum filtration
  7. washwashed with water (2×25 mL)
  8. customabsorbed on silica gel
  9. custompurified by flash chromatography

Sources & evidence

ORD record
ord-c7645b9a28a84c09a3b7867b1dd66ddb
Source dataset
uspto-grants-2013_12
Patent number
US08598174B2

Reaction notes

Loading…