Triacetoxyperiodinane → (R)-tert-butyl 1-(4-fluorophenyl)-4a-picolinoyl-4a,5,7,8-tetrahydro-1H-pyrazolo[3,4-g]isoquinoline-6(4H)-carboxylate

HRID 920614Notes

Reaction equation

HRID 920614 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:12]3[CH:13]=[C:14]4[C:19]([C@@H:21]([OH:28])[C:22]5[CH:27]=[CH:26][CH:25]=[CH:24][N:23]=5)([CH2:20][C:11]=3[CH:10]=[N:9]2)[CH2:18][N:17]([C:29]([O:31][C:32]([CH3:35])([CH3:34])[CH3:33])=[O:30])[CH2:16][CH2:15]4)=[CH:4][CH:3]=1.CC(OI1(OC(C)=O)(OC(C)=O)OC(=O)C2C1=CC=CC=2)=O.C(=O)([O-])O.[Na+]>ClCCl>[F:1][C:2]1[CH:3]=[CH:4][C:5]([N:8]2[C:12]3[CH:13]=[C:14]4[C@:19]([C:21](=[O:28])[C:22]5[CH:27]=[CH:26][CH:25]=[CH:24][N:23]=5)([CH2:20][C:11]=3[CH:10]=[N:9]2)[CH2:18][N:17]([C:29]([O:31][C:32]([CH3:35])([CH3:34])[CH3:33])=[O:30])[CH2:16][CH2:15]4)=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 159087TriacetoxyperiodinaneHCID 516892Sodium BicarbonateHCID 131731947(R)-tert-butyl 1-(4-fluorophenyl)-4a-(R/S)-(hydroxy(pyridin-2-yl)methyl)-4a,5,7,8-tetrahydro-1H-pyrazolo[3,4-g]isoquinoline-6(4H)-carboxylate

Product 1

HCID 86709979(R)-tert-butyl 1-(4-fluorophenyl)-4a-picolinoyl-4a,5,7,8-tetrahydro-1H-pyrazolo[3,4-g]isoquinoline-6(4H)-carboxylateYield 45.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of (R)-tert-butyl 1-(4-fluorophenyl)-4a-(R/S)-(hydroxy(pyridin-2-yl)methyl)-4a,5,7,8-tetrahydro-1H-pyrazolo[3,4-g]isoquinoline-6(4H)-carboxylate (410 mg, 0.86 mmol) in dry dichloromethane (10 mL) was treated with 1,1,1-triacetoxy-1,1-dihydro-1,2-benziodoxol-3(1H)-one (547 mg, 1.29 mmol; Dess-Martin periodinane) and the reaction mixture was stirred for 1 hour at room temperature. The reaction mixture was cooled and treated with saturated sodium hydrogen carbonate solution (20 mL) followed by dichloromethane (10 mL). The mixture was stirred for 10 minutes and the phases were separated. The aqueous phase was extracted with further dichloromethane (×2) and the combined organic phases dried over sodium sulfate. The solids were removed by filtration, the filtrate was concentrated under reduced pressure and the residue was purified by column chromatography on silica gel (gradient: 20-40% ethyl acetate in cyclohexane) to afford (R)-tert-butyl 1-(4-fluorophenyl)-4a-picolinoyl-4a,5,7,8-tetrahydro-1H-pyrazolo[3,4-g]isoquinoline-6(4H)-carboxylate as a pale yellow foam (185 mg). LCMS (Method B, ESI): RT 4.13 min, m+H=475.5; 1H NMR (400 MHz, CDCl3): δ 8.68 (d, J=4.8 Hz, 2 H); 7.44-7.45 (m, 5 H); 7.15-7.16 (m, 3 H); 6.51 (s, 2 H); 2.83 (br s, 5 H); 2.49 (s, 1 H); 1.43 (s, 9 H).

Workup

  1. temperatureThe reaction mixture was cooled
  2. stirringThe mixture was stirred for 10 minutes
  3. customthe phases were separated
  4. extractionThe aqueous phase was extracted with further dichloromethane (×2)
  5. dry with materialthe combined organic phases dried over sodium sulfate
  6. customThe solids were removed by filtration
  7. concentrationthe filtrate was concentrated under reduced pressure
  8. customthe residue was purified by column chromatography on silica gel (gradient: 20-40% ethyl acetate in cyclohexane)

Sources & evidence

ORD record
ord-117677a9acaa45ba9e6b9910291717f6
Source dataset
uspto-grants-2016_03
Patent number
US09273047B2

Reaction notes

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