Tetrahydrofuran → 1-(2-Aminopropyl)-1,4-dihydro-indeno[1,2-c]pyrazol-6-ol

HRID 585905Notes

Reaction equation

HRID 585905 reaction equation
C[O:2][C:3]1[CH:4]=[C:5]2[C:16](=[CH:17][CH:18]=1)[C:8]1[N:9]([CH2:12][CH:13]([NH2:15])[CH3:14])[N:10]=[CH:11][C:7]=1[CH2:6]2.[B-](Br)(Br)(Br)[S+](C)C.C1COCC1.C([O-])(O)=O.[Na+]>ClCCCl>[NH2:15][CH:13]([CH3:14])[CH2:12][N:9]1[C:8]2[C:16]3[C:5]([CH2:6][C:7]=2[CH:11]=[N:10]1)=[CH:4][C:3]([OH:2])=[CH:18][CH:17]=3

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 516892Sodium BicarbonateHCID 4181510Tribromoborane-methyl sulfideHCID 223383072-(6-Methoxy-4H-indeno[1,2-c]pyrazol-1-yl)-1-methylethylamine

Product 1

HCID 1354860361-(2-Aminopropyl)-1,4-dihydro-indeno[1,2-c]pyrazol-6-olYield 13.3%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

To a solution of the product from Step D (0.56 g, 0.23 mmol) in 1,2-dichloroethane (10 mL) was added boron tribromide-methylsulfide complex in THF solution (1.0M, 0.5 mL, 0.5 mmol) and the solution heated to reflux for 16 h. The solution was allowed to cool, poured into aqueous NaHCO3, extracted with chloroform (2×20 mL), dried (Na2SO4) and concentrated. The crude product was purified by chromatography (silica, 20% methanol in dichloromethane) to give a solid (0.007 g, 13%): 1H NMR (CDCl3) δ7.39 (m, 2H), 7.00 (s, 1H), 6.79 (dd, J=8.4, 2.4 Hz, 1H), 4.30 (dd, J=13.8, 4.8 Hz, 1H), 4.14 (dd, J=13.8,7.8Hz, 1H), 3.55 (m, 1H), 3.48 (bm, 4H), 1.19 (d, J=6.6 Hz, 3H); MS m/z 230 [M+H]+.

Workup

  1. temperaturethe solution heated
  2. temperatureto reflux for 16 h
  3. temperatureto cool
  4. extractionextracted with chloroform (2×20 mL)
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated
  7. customThe crude product was purified by chromatography (silica, 20% methanol in dichloromethane)

Sources & evidence

ORD record
ord-df3b2428b578474492ea58f22cf629fa
Source dataset
uspto-grants-2005_08
Patent number
US06933392B2

Reaction notes

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