Boron trifluoride etherate → HCID 86713796, compound

HRID 521851Notes

Reaction equation

HRID 521851 reaction equation
CO[CH:3]1[O:8][CH:7]([C:9]2[N:13]([CH3:14])[N:12]=[CH:11][C:10]=2[N+:15]([O-:17])=[O:16])[CH:6]([CH3:18])[CH:5]=[C:4]1[CH3:19].B(F)(F)F.CCOCC.C([SiH](CC)CC)C.C([O-])(O)=O.[Na+]>C(Cl)Cl>[CH3:18][CH:6]1[CH:5]=[C:4]([CH3:19])[CH2:3][O:8][CH:7]1[C:9]1[N:13]([CH3:14])[N:12]=[CH:11][C:10]=1[N+:15]([O-:17])=[O:16]

Participants

6

Reactant 4

HCID 8000Boron trifluoride etherateHCID 12052TriethylsilaneHCID 516892Sodium BicarbonateHCID 86713797HCID 86713797, compound

Product 1

HCID 86713796HCID 86713796, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-78 °C

Procedure

To a solution of 5-(6-methoxy-3,5-dimethyl-3,6-dihydro-2H-pyran-2-yl)-1-methyl-4-nitro-pyrazole (100 mg, 0.38 mmol) in DCM (1 mL) cooled to −78° C. was added boron trifluoride diethyl etherate (0.14 mL, 1.13 mmol) and triethylsilane (0.36 mL), 2.68 mmol). After stirring at −78° C. for 1 hr, the reaction mixture was allowed to warm to room temperature and stirred for 18 hr. Saturated aqueous NaHCO3 (5 mL) and DCM (5 mL) were added and the organic layer was passed through a phase separation cartridge and concentrated under reduced pressure. Purification via silica gel column chromatography (0-60% EtOAc/isohexane) gave 5-(3,5-dimethyl-3,6-dihydro-2H-pyran-2-yl)-1-methyl-4-nitro-pyrazole as a yellow oil. The reaction was repeated to provide more material. To a solution of 5-(3,5-dimethyl-3,6-dihydro-2H-pyran-2-yl)-1-methyl-4-nitro-pyrazole (305 mg, 1.29 mmol) in DCM (6.5 mL) cooled to 0° C. was added m-CPBA (70-75%, 382 mg, 1.54 mmol) and the mixture was stirred at 0° C. for 90 min. More m-CPBA (70-75%, 191 mg, 0.774 mmol) was added and the mixture was slowly warmed to room temperature over 6 hr. The mixture was filtered through Celite® washing with DCM (15 mL) and the filtrate washed with saturated aqueous NaHCO3 (2×10 mL). The organic layer was passed through a phase separation cartridge and concentrated under reduced pressure. Purification via silica gel column chromatography (0-60% EtOAc/isohexane) gave 5-(2,6-dimethyl-4,7-dioxabicyclo[4.1.0]heptan-3-yl)-1-methyl-4-nitro-pyrazole as a single diastereomer as an off-white solid (189 mg, 53% over two steps). 1H NMR (400 MHz, CDCl3) δ 8.08 (s, 1H), 5.32-5.28 (m, 1H), 4.15-4.08 (m, 1H), 4.06 (s, 3H), 3.78 (d, J=12.9 Hz, 1H), 3.30 (d, J=5.6 Hz, 1H), 2.71-2.61 (m, 1H), 1.38 (s, 3H), 0.92 (d, J=7.0 Hz, 3H).

Workup

  1. temperatureto warm to room temperature
  2. stirringstirred for 18 hr
  3. customthe organic layer was passed through a phase separation cartridge
  4. concentrationconcentrated under reduced pressure
  5. customPurification via silica gel column chromatography (0-60% EtOAc/isohexane)

Sources & evidence

ORD record
ord-0d243e493f5647f4b9a258e4345a53df
Source dataset
uspto-grants-2016_05
Patent number
US09328106B2

Reaction notes

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