m-Chloroperbenzoic acid → 5-(5,8-Dioxabicyclo[5.1.0]octan-4-yl)-1-methyl-4-nitro-pyrazole

HRID 521844Notes

Reaction equation

HRID 521844 reaction equation
[CH3:1][N:2]1[C:6]([CH:7]2[CH2:13][CH2:12][CH:11]=[CH:10][CH2:9][O:8]2)=[C:5]([N+:14]([O-:16])=[O:15])[CH:4]=[N:3]1.C1C=C(Cl)C=C(C(OO)=[O:25])C=1>C(Cl)Cl>[CH:11]12[O:25][CH:10]1[CH2:9][O:8][CH:7]([C:6]1[N:2]([CH3:1])[N:3]=[CH:4][C:5]=1[N+:14]([O-:16])=[O:15])[CH2:13][CH2:12]2

Participants

4

Reactant 2

HCID 70297m-Chloroperbenzoic acidHCID 867137771-Methyl-4-nitro-5-(2,3,4,7-tetrahydrooxepin-2-yl)pyrazole

Product 1

HCID 867138335-(5,8-Dioxabicyclo[5.1.0]octan-4-yl)-1-methyl-4-nitro-pyrazoleYield 43.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

To a solution of 1-methyl-4-nitro-5-(2,3,4,7-tetrahydrooxepin-2-yl)pyrazole (1.00 g, 4.74 mmol) in DCM (25 mL) was added m-CPBA (70-75%, 1.75 g, 7.11 mmol) and the reaction mixture was stirred at room temperature for 18 hr. The reaction mixture was diluted with DCM (50 mL), washed with saturated aqueous NaHCO3 (50 mL), water (50 mL) and brine (50 mL). The organic layer was separated, dried over MgSO4, and concentrated under reduced pressure. Purification via silica gel column chromatography (0-30% EtOAc/isohexane) gave racemic 5-(5,8-dioxabicyclo[5.1.0]octan-4-yl)-1-methyl-4-nitro-pyrazole as a colourless solid (490 mg, 43%). 1H NMR (400 MHz, CDCl3) δ 8.22-7.87 (m, 1H), 5.07 (d, J=9.9 Hz, 1H), 4.50 (dd, J=14.5, 3.1 Hz, 1H), 4.05 (s, 3H), 3.93 (d, J=14.4 Hz, 1H), 3.35 (t, J=4.5 Hz, 1H), 3.13 (t, J=3.6 Hz, 1H), 2.55-2.47 (m, 1H), 2.31-2.21 (m, 1H), 2.16-2.04 (m, 1H), 1.79 (dd, J=14.4, 1.8 Hz, 1H).

Workup

  1. washwashed with saturated aqueous NaHCO3 (50 mL), water (50 mL) and brine (50 mL)
  2. customThe organic layer was separated
  3. dry with materialdried over MgSO4
  4. concentrationconcentrated under reduced pressure
  5. customPurification via silica gel column chromatography (0-30% EtOAc/isohexane)

Sources & evidence

ORD record
ord-625d41745ebf41e2b9301853e7e94b88
Source dataset
uspto-grants-2016_05
Patent number
US09328106B2

Reaction notes

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